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1110.0981 | The Fermi surface (FS) nesting properties of URu$_2$Si$_2$ are analyzed with
particular focus on their implication for the mysterious hidden order phase. We
show that there exist two Fermi surfaces that exhibit a strong nesting at the
antiferromagnetic wavevector, $\boldsymbol{Q}_0$=(0,\,0,\,1). The corresponding
energy dispersions fulfill the relation $\epsilon_{1}(\boldsymbol{k})$=$-
\epsilon_{2} (\boldsymbol{k}\pm \boldsymbol{Q}_0)$ at eight FS hotspot lines.
The spin-orbital characters of the involved $5f$ states are {\it distinct}
($j_z$=$\pm$5/2 {\it vs.} $\pm$3/2) and hence the degenerate Dirac crossings
are symmetry protected in the nonmagnetic normal state. Dynamical symmetry
breaking through an Ising-like spin and orbital excitation mode with $\Delta
j_z$=$\pm$1 induces a hybridization of the two states, causing substantial FS
gapping. Concomitant spin and orbital currents in the uranium planes give rise
to a rotational symmetry breaking.
| [
"cond-mat.str-el"
] | cond-mat.str-el | Strongly Correlated Electrons | 6,979Strongly Correlated Electrons
|
|
1903.01931 | In this paper, we propose Orthogonal Generative Adversarial Networks
(O-GANs). We decompose the network of discriminator orthogonally and add an
extra loss into the objective of common GANs, which can enforce discriminator
become an effective encoder. The same extra loss can be embedded into any kind
of GANs and there is almost no increase in computation. Furthermore, we discuss
the principle of our method, which is relative to the fully-exploiting of the
remaining degrees of freedom of discriminator. As we know, our solution is the
simplest approach to train a generative adversarial network with auto-encoding
ability.
| [
"cs.CV",
"cs.LG"
] | cs.CV | cs.LG | Computer Vision and Pattern Recognition;Machine Learning | 1,593Computer Vision and Pattern Recognition;Machine Learning
|
1205.0382 | Living cell signaling systems include multistep biochemical signaling
reaction cascades (BSCs) comprising modifications of molecular signaling
proteins. Substantial data on BSCs have been accumulated in the field of
molecular biology and the analysis of signaling systems requires qualitative
evaluation. However, quantification of the information and channel capacity of
BSCs has not been focused on from the perspective of information theory. In the
current study, we aimed to derive basic equations for describing the channel
capacity and information density of BSCs using the fluctuation theorem. From
the results, channel capacity and information density can be described using
the average entropy production rate when the signaling system is minimally
redundant. The channel capacity could actually be calculated for the
mitogen-activated protein kinase BSC when it was minimally redundant. This
quantitative method of examination is applicable to the quantitative analysis
of BSCs.
| [
"q-bio.MN"
] | q-bio.MN | Molecular Networks | 4,646Molecular Networks
|
|
2007.08934 | In this paper, we propose offline and online adaptive enrichment algorithms
for the generalized multiscale approximation of a mixed finite element method
with velocity elimination to solve the subsurface flow problem in high-contrast
and heterogeneous porous media. We give the theoretical analysis for the
convergence of these two adaptive methods, which shows that sufficient initial
basis functions (belong to the offline space) leads to a faster convergence
rate. A series of numerical examples are provided to highlight the performance
of both these two adaptive methods and also validate the theoretical analysis.
Both offline and online adaptive methods are effective that can reduce the
relative error substantially. In addition, the online adaptive method generally
performs better than the offline adaptive method as online basis functions
contain important global information such as distant effects that cannot be
captured by offline basis functions. The numerical results also show that with
a suitable initial multiscale space that includes all offline basis functions
corresponding to relative smaller eigenvalues of local spectral decompositions
in the offline stage, the convergence rate of the online enrichment is
independent of the permeability contrast.
| [
"math.NA",
"cs.NA"
] | math.NA | cs.NA | Numerical Analysis;Numerical Analysis | 5,059Numerical Analysis;Numerical Analysis
|
2312.14327 | Abbreviation expansion is a strategy used to speed up communication by
limiting the amount of typing and using a language model to suggest expansions.
Here we look at personalizing a Large Language Model's (LLM) suggestions based
on prior conversations to enhance the relevance of predictions, particularly
when the user data is small (~1000 samples). Specifically, we compare
fine-tuning, prompt-tuning, and retrieval augmented generation of expanded text
suggestions for abbreviated inputs. Our case study with a deployed 8B parameter
LLM on a real user living with ALS, and experiments on movie character
personalization indicates that (1) customization may be necessary in some
scenarios and prompt-tuning generalizes well to those, (2) fine-tuning on
in-domain data (with as few as 600 samples) still shows some gains, however (3)
retrieval augmented few-shot selection also outperforms fine-tuning. (4)
Parameter efficient tuning allows for efficient and scalable personalization.
For prompt-tuning, we also find that initializing the learned "soft-prompts" to
user relevant concept tokens leads to higher accuracy than random
initialization.
| [
"cs.CL"
] | cs.CL | Computation and Language | 1,168Computation and Language
|
|
1506.06823 | We introduce new quantities for exploratory causal inference between
bivariate time series. The quantities, called penchants and leanings, are
computationally straightforward to apply, follow directly from assumptions of
probabilistic causality, do not depend on any assumed models for the time
series generating process, and do not rely on any embedding procedures; these
features may provide a clearer interpretation of the results than those from
existing time series causality tools. The penchant and leaning are computed
based on a structured method for computing probabilities.
| [
"physics.data-an",
"stat.ME"
] | physics.data-an | stat.ME | Data Analysis, Statistics and Probability;Methodology | 1,894Data Analysis, Statistics and Probability;Methodology
|
1607.06853 | Present laboratory limits on the coupling strength of anomalous pseudoscalar
and axial interactions are many orders of magnitude weaker than their scalar
and vector analogs. Here we investigate two mechanisms which can circumvent
this suppression and thereby lead to improved limits.
| [
"hep-ph",
"nucl-th"
] | hep-ph | nucl-th | High Energy Physics - Phenomenology;Nuclear Theory | 3,240High Energy Physics - Phenomenology;Nuclear Theory
|
1904.02680 | Quantum resource theories have been widely studied to systematically
characterize the non-classicality of quantum systems. Most resource theories
focus on quantum states and study their interconversions. Although quantum
channels are generally used as the tool for state manipulation, such a
manipulation capability can be naturally regarded as a generalized quantum
resource, leading to an open research direction in the resource theories of
quantum channels. Various resource-theoretic properties of channels have been
investigated, however, without treating channels themselves as operational
resources that can also be manipulated and converted. In this Letter, we
address this problem by first proposing a general resource framework for
quantum channels and introducing resource monotones based on general distance
quantifiers of channels. We study the interplay between channel and state
resource theories by relating resource monotones of a quantum channel to its
manipulation power of the state resource. Regarding channels as operational
resources, we introduce asymptotic channel distillation and dilution, the most
important tasks in an operational resource theory, and show how to bound the
conversion rates with channel resource monotones. Finally, we apply our results
to quantum coherence as an example and introduce the coherence of channels,
which characterizes the coherence generation ability of channels. We consider
asymptotic channel distillation and dilution with maximally incoherent
operations and find the theory asymptotically irreversible, in contrast to the
asymptotic reversibility of the coherence of states.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
1006.1939 | A quasi-tree is a geodesic metric space quasi-isometric to a tree. We give a
general construction of many actions of groups on quasi-trees. The groups we
can handle include non-elementary (relatively) hyperbolic groups, rank 1 CAT(0)
groups, mapping class groups and Out(Fn). As an application, we show that
mapping class groups act on finite products of {\delta}-hyperbolic spaces so
that orbit maps are quasi-isometric embeddings. We prove that mapping class
groups have finite asymptotic dimension.
| [
"math.GR",
"math.GT"
] | math.GR | math.GT | Group Theory;Geometric Topology | 2,950Group Theory;Geometric Topology
|
1511.06775 | Darwin's theory of evolution - as introduced in game theory by Maynard Smith
- is not the only important evolutionary aspect in a evolutionary dynamics,
since complex interdependencies, competition, and growth should be modeled by,
for example, reactive aspects. In the ultimatum game the reciprocity and the
fifty-fifty partition seems to be a deviation from rational behavior of the
players under the light of the Nash equilibrium concept.Such equilibrium
emerges, for example, from the punishment of the responder who generally tends
to refuse unfair proposals. In the iterated version of the game, the proposers
are able to improve their proposals by adding a value thus making fairer
proposals. Such evolutionary aspects are not properly Darwinian-motivated, but
they are endowed with a fundamental aspect: they reflect their actions
according to value of the offers. Recently, a reactive version of the ultimatum
game where acceptance occurs with fixed probability was proposed. In this
paper, we aim at exploring this reactive version of the ultimatum game where
the acceptance by players depends on the offer. In order to do so, we analyze
two situations: (i) mean field and (ii) we consider players inserted within the
networks with arbitrary coordination. We then show that the reactive aspect,
here studied, thus far not analyzed in the evolutionary game theory literature
can unveil an essential feature for the convergence to fifty-fifty split.
Moreover we also analyze populations under four different polices ranging from
a highly conservative to a moderate one, with respect to decision in changing
the proposal based on acceptations. We show that the idea of gaining less more
times added to the reciprocity of the players is highly relevant to the
"healthy" societies population bargaining concept.
| [
"physics.soc-ph"
] | physics.soc-ph | Physics and Society | 5,463Physics and Society
|
|
2103.02918 | Let $A$ be a Noetherian flat $K[t]$-algebra, $h$ an integer and let $N$ be a
graded $K[t]$-module, we introduce and study "$N$-fiber-full up to $h$"
$A$-modules. We prove that an $A$-module $M$ is $N$-fiber-full up to $h$ if and
only if $\mathrm{Ext}^i_A(M, N)$ is flat over $K[t]$ for all $i\le h-1$. And we
show some applications of this result extending the recent result on squarefree
Gr\"obner degenerations by Conca and Varbaro.
| [
"math.AC"
] | math.AC | Commutative Algebra | 1,107Commutative Algebra
|
|
2009.13831 | In this paper, we treat the problem of testing for normality as a binary
classification problem and construct a feedforward neural network that can
successfully detect normal distributions by inspecting small samples from them.
The numerical experiments conducted on small samples with no more than 100
elements indicated that the neural network which we trained was more accurate
and far more powerful than the most frequently used and most powerful standard
tests of normality: Shapiro-Wilk, Anderson-Darling, Lilliefors and
Jarque-Berra, as well as the kernel tests of goodness-of-fit. The neural
network had the AUROC score of almost 1, which corresponds to the perfect
binary classifier. Additionally, the network's accuracy was higher than 96% on
a set of larger samples with 250-1000 elements. Since the normality of data is
an assumption of numerous techniques for analysis and inference, the neural
network constructed in this study has a very high potential for use in everyday
practice of statistics, data analysis and machine learning in both science and
industry.
| [
"stat.ML",
"cs.LG",
"stat.ME"
] | stat.ML | cs.LG | Machine Learning;Machine Learning;Methodology | 4,183Machine Learning;Machine Learning;Methodology
|
1903.07576 | In this paper we study the existence and linear stability of almost periodic
solutions for a NLS equation on the circle with external parameters. Starting
from the seminal result of Bourgain (2005) on the quintic NLS, we propose a
novel approach allowing to prove in a unified framework the persistence of
finite and infinite dimensional invariant tori, which are the support of the
desired solutions. The persistence result is given through a rather abstract
"counter-term theorem" `a la Herman, directly in the original elliptic
variables without passing to action-angle ones. Our framework allows us to find
"many more" almost periodic solutions with respect to the existing literature
and consider also non-translation invariant PDEs.
| [
"math.AP"
] | math.AP | Analysis of PDEs | 205Analysis of PDEs
|
|
0903.2938 | A semimetal-insulator transition in the Hubbard model on the honeycomb
lattice is studied by using the dynamical mean field theory. Electrons in the
honeycomb lattice resemble the Dirac electron liquid and for weak interactions
the system is semimetal. With increasing the local interaction a
semimetal-insulator transition occurs. We find a nonanalytical structure of the
phase transition which consists of a first-order transition line ending in a
second-order transition point and high-temperature crossover line. A phase
separation of semimetal and insulator occurs at low temperatures. Maxwell
construction is performed to determine the first order transition line. The
phase diagram is also presented.
| [
"cond-mat.str-el"
] | cond-mat.str-el | Strongly Correlated Electrons | 6,979Strongly Correlated Electrons
|
|
2303.16252 | Task-oriented dialog systems empower users to accomplish their goals by
facilitating intuitive and expressive natural language interactions.
State-of-the-art approaches in task-oriented dialog systems formulate the
problem as a conditional sequence generation task and fine-tune pre-trained
causal language models in the supervised setting. This requires labeled
training data for each new domain or task, and acquiring such data is
prohibitively laborious and expensive, thus making it a bottleneck for scaling
systems to a wide range of domains. To overcome this challenge, we introduce a
novel Zero-Shot generalizable end-to-end Task-oriented Dialog system, ZS-ToD,
that leverages domain schemas to allow for robust generalization to unseen
domains and exploits effective summarization of the dialog history. We employ
GPT-2 as a backbone model and introduce a two-step training process where the
goal of the first step is to learn the general structure of the dialog data and
the second step optimizes the response generation as well as intermediate
outputs, such as dialog state and system actions. As opposed to
state-of-the-art systems that are trained to fulfill certain intents in the
given domains and memorize task-specific conversational patterns, ZS-ToD learns
generic task-completion skills by comprehending domain semantics via domain
schemas and generalizing to unseen domains seamlessly. We conduct an extensive
experimental evaluation on SGD and SGD-X datasets that span up to 20 unique
domains and ZS-ToD outperforms state-of-the-art systems on key metrics, with an
improvement of +17% on joint goal accuracy and +5 on inform. Additionally, we
present a detailed ablation study to demonstrate the effectiveness of the
proposed components and training mechanism
| [
"cs.CL",
"cs.LG"
] | cs.CL | cs.LG | Computation and Language;Machine Learning | 1,237Computation and Language;Machine Learning
|
physics/0603205 | We propose a mechanism for the low frequency electromagnetic emissions and
other electromagnetic phenomena which have been associated with earthquakes.
The mechanism combines the critical earthquake concept and the concept of crust
acting as a charging electric battery under increasing stress. The electric
charges are released by activation of dormant charge carriers in the oxygen
anion sublattice, called peroxy bonds or positive hole pairs (PHP), where a PHP
represents an $O_3X/^{OO}\backslash YO_3$ with $X,Y = Si^{4+}, Al^{3+}...$,
i.e. an $O^-$ in a matrix of $O^{2-}$ of silicates. We propose that PHP are
activated by plastic deformations during the slow cooperative build-up of
stress and the increasingly correlated damage culminating in a large
``critical'' earthquake. Recent laboratory experiments indeed show that
stressed rocks form electric batteries which can release their charge when a
conducting path closes the equivalent electric circuit. We conjecture that the
intermittent and erratic occurrences of EM signals are a consequence of the
progressive build-up of the battery charges in the Earth crust and their
erratic release when crack networks are percolating throughout the stressed
rock volumes, providing a conductive pathway for the battery currents to
discharge. EM signals are thus expected close to the rupture, either slightly
before or after, that is, when percolation is most favored.
| [
"physics.geo-ph",
"physics.gen-ph"
] | physics.geo-ph | physics.gen-ph | Geophysics;General Physics | 2,881Geophysics;General Physics
|
2312.12225 | Metric perturbations induced by ultralight dark matter (ULDM) fields have
long been identified as a potential target for pulsar timing array (PTA)
observations. Previous works have focused on the coherent oscillation of metric
perturbations at the characteristic frequency set by the ULDM mass. In this
work, we show that ULDM fields source low-frequency stochastic metric
fluctuations and that these low-frequency fluctuations can produce distinctive
detectable signals in PTA data. Using the NANOGrav 12.5-year data set and
synthetic data sets mimicking present and future PTA capabilities, we show that
the current and future PTA observations provide the strongest probe of ULDM
density within the solar system for masses in the range of $10^{-18}\;{\rm
eV}-10^{-16}\;{\rm eV}$.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2011.14118 | In the case of airborne diseases, pathogen copies are transmitted by droplets
of respiratory tract fluid that are exhaled by the infectious and, after
partial or full drying, inhaled as aerosols by the susceptible. The risk of
infection in indoor environments is typically modelled using the Wells-Riley
model or a Wells-Riley-like formulation, usually assuming the pathogen dose
follows a Poisson distribution (mono-pathogen assumption). Aerosols that hold
more than one pathogen copy, i.e. poly-pathogen aerosols, break this assumption
even if the aerosol dose itself follows a Poisson distribution. For the largest
aerosols where the number of pathogen in each aerosol can sometimes be several
hundred or several thousand, the effect is non-negligible, especially in
diseases where the risk of infection per pathogen is high. Here we report on a
generalization of the Wells-Riley model and dose-response models for
poly-pathogen aerosols by separately modeling each number of pathogen copies
per aerosol, while the aerosol dose itself follows a Poisson distribution. This
results in a model for computational risk assessment suitable for
mono-/poly-pathogen aerosols. We show that the mono-pathogen assumption
significantly overestimates the risk of infection for high pathogen
concentrations in the respiratory tract fluid. The model also includes the
aerosol removal due to filtering by the individuals which becomes significant
for poorly ventilated environments with a high density of individuals, and
systematically includes the effects of facemasks in the infectious aerosol
source and sink terms and dose calculations.
| [
"q-bio.QM",
"physics.med-ph"
] | q-bio.QM | physics.med-ph | Quantitative Methods;Medical Physics | 5,855Quantitative Methods;Medical Physics
|
astro-ph/0510143 | SHARC II, 350-micron continuum and archival HST J-H band maps are presented
of NGC 3656, the brightest of our sample of six elliptical galaxies for which
resolved CO gas disks have recently been detected with 7''-spatial-resolution,
interferometry mapping. These gas disks confirm the conclusions of earlier
results showing optical dust lanes and unresolved CO that implied the common
existence of molecular gas in ellipticals and the disk-like structure of this
gas. The presented SHARC II mapping results provide the best to date resolved
FIR-submm extent of NGC 3656 and of any elliptical galaxy > 40 Mpc, showing
that dust of 29 K exists out to at least 1.8 kpc in this galaxy. These new data
are used in conjunction with the archival HST maps and other published data to
determine dust properties and associations with galactic structures, including
dominant heating sources such as nuclear-activity, star-formation or
diffuse-stellar radiation.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
1612.08907 | In an ordinary billiard trajectories of a Hamiltonian system are elastically
reflected after a collision with a hypersurface (scatterer). If the scatterer
is a submanifold of codimension more than one, we say that the billiard is
degenerate. Degenerate billiards appear as limits of systems with singularities
in celestial mechanics. We prove the existence of trajectories of such systems
shadowing trajectories of the corresponding degenerate billiards. This research
is motivated by the problem of second species solutions of Poincar\'e.
| [
"math.DS"
] | math.DS | Dynamical Systems | 2,265Dynamical Systems
|
|
hep-th/9609185 | In 1+1 dimensions two different formulations exist of SU(N) Yang Mills
theories in light-cone gauge; only one of them gives results which comply with
the ones obtained in Feynman gauge. Moreover the theory, when considered in
1+(D-1) dimensions, looks discontinuous in the limit D=2. All those features
are proven in Wilson loop calculations as well as in the study of the $q\bar q$
bound state integral equation in the large N limit.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
cond-mat/0304552 | We have investigated the MoSr2R1.5Ce0.5Cu2O10-d (Mo-1222R, R=rare earth)
system by several complementary experimental techniques. In contrast to the
iso-structural RuSr2R1.5Ce0.5Cu2O10-d (Ru-1222) system, in which
superconductivity (SC) in the CuO2 planes and weak-ferromagnetism in the Ru
sub-lattice coexists, in Mo-1222, displays a competition between the two
states, namely, SC vanishes when the magnetic order sets in. The contraction in
the R elements leads to a change of the physical states. The light R ions (Pr
and Nd) are paramagnetic down to 5 K, whereas the middle R ions (Sm and Eu) are
SC at TC 18-23 K respectively. The SC charge carriers originate from the CuO2
planes, and annealing under oxygen pressures does not affect TC. A simple model
for the SC state is proposed. For the heavy R elements Ho-Lu and Y, the
pentavalent Mo layers are antiferromagnetically (AFM) ordered at TN ranging
from 13-26 K. For R=Gd, the sample is not SC and exhibit two magnetic
transitions at 11 and 184 K. Both the SC or AFM states depend strongly on the
R/Ce ratio and for R/Ce=1, both states are suppressed.
| [
"cond-mat.supr-con"
] | cond-mat.supr-con | Superconductivity | 7,066Superconductivity
|
|
1005.0354 | We define a "quantum relation" on a von Neumann algebra M \subset B(H) to be
a weak* closed operator bimodule over its commutant M'. Although this
definition is framed in terms of a particular representation of M, it is
effectively representation independent. Quantum relations on l^\infty(X)
exactly correspond to subsets of X^2, i.e., relations on X. There is also a
good definition of a "measurable relation" on a measure space, to which quantum
relations partially reduce in the general abelian case. By analogy with the
classical setting, we can identify structures such as quantum equivalence
relations, quantum partial orders, and quantum graphs, and we can generalize
Arveson's fundamental work on weak* closed operator algebras containing a masa
to these cases. We are also able to intrinsically characterize the quantum
relations on M in terms of families of projections in M \otimes B(l^2).
| [
"math.OA",
"math.FA"
] | math.OA | math.FA | Operator Algebras;Functional Analysis | 5,121Operator Algebras;Functional Analysis
|
2206.05859 | This work introduces Directed-Evolution (DE) method for sparsification of
neural networks, where the relevance of parameters to the network accuracy is
directly assessed and the parameters that produce the least effect on accuracy
when tentatively zeroed are indeed zeroed. DE method avoids a potentially
combinatorial explosion of all possible candidate sets of parameters to be
zeroed in large networks by mimicking evolution in the natural world. DE uses a
distillation context [5]. In this context, the original network is the teacher
and DE evolves the student neural network to the sparsification goal while
maintaining minimal divergence between teacher and student. After the desired
sparsification level is reached in each layer of the network by DE, a variety
of quantization alternatives are used on the surviving parameters to find the
lowest number of bits for their representation with acceptable loss of
accuracy. A procedure to find optimal distribution of quantization levels in
each sparsified layer is presented. Suitable final lossless encoding of the
surviving quantized parameters is used for the final parameter representation.
DE was used in sample of representative neural networks using MNIST,
FashionMNIST and COCO data sets with progressive larger networks. An 80 classes
YOLOv3 with more than 60 million parameters network trained on COCO dataset
reached 90% sparsification and correctly identifies and segments all objects
identified by the original network with more than 80% confidence using 4bit
parameter quantization. Compression between 40x and 80x. It has not escaped the
authors that techniques from different methods can be nested. Once the best
parameter set for sparsification is identified in a cycle of DE, a decision on
zeroing only a sub-set of those parameters can be made using a combination of
criteria like parameter magnitude and Hessian approximations.
| [
"cs.LG",
"cs.CV",
"cs.NE"
] | cs.LG | cs.CV | Machine Learning;Computer Vision and Pattern Recognition;Neural and Evolutionary Computing | 4,060Machine Learning;Computer Vision and Pattern Recognition;Neural and Evolutionary Computing
|
2306.05193 | We study the Wannier-Stark (WS) localization in one-dimensional
amplitude-chirped lattices with the $j$th onsite potential modulated by a
function $Fj\cos(2\pi \alpha j)$, where $F$ is the external field with a period
determined by $\alpha=p/q$ ($p$ and $q$ are coprime integers). In the Hermitian
(or non-Hermitian) systems with real (or imaginary) fields, we can obtain real
(or imaginary) WS ladders in the eigenenergy spectrum. In most cases with $q
\geq 2$, there are multiple WS ladders with all the eigenstates localized in
the strong field limit. However, in the lattices with $q=4$, the
energy-dependent localization phenomenon emerges due to the presence of both
spatially periodic and linearly increasing behaviors in the onsite potential.
About half the number of eigenstates are gathered at the band center and can
extend over a wide region or even the full range of the lattice, even when the
field becomes very strong. Moreover, in the non-Hermitian lattices with odd
$q$, some of the WS ladders become doubly degenerate, where the eigenstates are
evenly distributed at two neighboring sites in a wide regime of field strength.
Our work opens an avenue for exploring WS localization in both Hermitian and
non-Hermitian amplitude-chirped lattices.
| [
"cond-mat.dis-nn",
"quant-ph"
] | cond-mat.dis-nn | quant-ph | Disordered Systems and Neural Networks;Quantum Physics | 2,169Disordered Systems and Neural Networks;Quantum Physics
|
1506.07784 | Recent works related to Palis conjecture of J. Yang, S. Crovisier, M.
Sambarino and D. Yang showed that any aperiodic class of a $C^1$-generic
diffeomorphism far away from homoclinic bifurcations (or homoclinic tangencies)
is partially hyperbolic. We show in this paper that, generically, a non-trivial
dominated splitting implies partial hyperbolicity for an aperiodic class if it
is Lyapunov stable. More precisely, for $C^1$-generic diffeomorphisms, if a
Lyapunov stable aperiodic class has a non-trivial dominated splitting $E\oplus
F$, then one of the two bundles is hyperbolic (either $E$ is contracted or $F$
is expanded).
| [
"math.DS"
] | math.DS | Dynamical Systems | 2,265Dynamical Systems
|
|
nlin/0308007 | Short planar glow discharges coupled to a resistive layer exhibit a wealth of
spontaneous spatio-temporal patterns. Several authors have suggested effective
reaction-diffusion-models to explore similarities with other pattern forming
systems. To test these effective models, we here investigate the temporal
oscillations of a glow discharge layer coupled to a linear resistor. We find an
unexpected cascade of period doubling events. This shows that the inner
structure of the discharge is more complex than can be described by a
reaction-diffusion-model with negative differential conductivity.
| [
"nlin.PS"
] | nlin.PS | Pattern Formation and Solitons | 5,407Pattern Formation and Solitons
|
|
1702.03995 | These notes are defining the notion of centric linking system for a locally
finite group If a locally finite group $G$ has countable Sylow $p$-subgroups,
we prove that, with a countable condition on the set of intersections, the
$p$-completion of its classifying space is homotopy equivalent to the
$p$-completion of the nerve of its centric linking system.
| [
"math.AT",
"math.GR"
] | math.AT | math.GR | Algebraic Topology;Group Theory | 190Algebraic Topology;Group Theory
|
1307.7547 | We propose a new algorithm for the solution of the robust multiple-load
topology optimization problem. The algorithm can be applied to any type of
problem, e.g., truss topology, variable thickness sheet or free material
optimization. We assume that the given loads are uncertain and can be subject
to small random perturbations. Furthermore, we define a rigorous measure of
robustness of the given design with respect to these perturbations. To
implement the algorithm, the users only need software to solve their standard
multiple-load problem. Additionally, they have to solve a few small-dimensional
eigenvalue problems. Numerical examples demonstrate the efficiency of our
approach.
| [
"math.OC",
"math.NA"
] | math.OC | math.NA | Optimization and Control;Numerical Analysis | 5,318Optimization and Control;Numerical Analysis
|
0704.1832 | We make use of new near and mid-IR photometry of the Pleiades cluster in
order to help identify proposed cluster members. We also use the new photometry
with previously published photometry to define the single-star main sequence
locus at the age of the Pleiades in a variety of color-magnitude planes.
The new near and mid-IR photometry extend effectively two magnitudes deeper
than the 2MASS All-Sky Point Source catalog, and hence allow us to select a new
set of candidate very low mass and sub-stellar mass members of the Pleiades in
the central square degree of the cluster. We identify 42 new candidate members
fainter than Ks =14 (corresponding to 0.1 Mo). These candidate members should
eventually allow a better estimate of the cluster mass function to be made down
to of order 0.04 solar masses.
We also use new IRAC data, in particular the images obtained at 8 um, in
order to comment briefly on interstellar dust in and near the Pleiades. We
confirm, as expected, that -- with one exception -- a sample of low mass stars
recently identified as having 24 um excesses due to debris disks do not have
significant excesses at IRAC wavelengths. However, evidence is also presented
that several of the Pleiades high mass stars are found to be impacting with
local condensations of the molecular cloud that is passing through the Pleiades
at the current epoch.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2012.07083 | In this note we will describe a simple and practical approach to get rigorous
bounds on the Hausdorff dimension of limits sets for some one dimensional
Markov iterated function schemes. The general problem has attracted
considerable attention, but we are particularly concerned with the role of the
value of the Hausdorff dimension in solving conjectures and problems in other
areas red of mathematics. As our first application we confirm, and often
strengthen, conjectures on the difference of the Lagrange and Markov spectra in
Diophantine analysis, which appear in the work of Matheus and Moreira
arXiv:1803.01230. As a second application we (re-)validate and improve
estimates connected with the Zaremba conjecture in number theory, used in the
work of Bourgain-Kontorovich arXiv:1107.3776v2, Huang arXiv:1310.3772v4 and Kan
arXiv:1604.04884. As a third more geometric application, we rigorously bound
the bottom of the spectrum of the Laplacian for infinite area surfaces, as
illustrated by an example studied by McMullen. In all approaches to estimating
the dimension of limit sets there are questions about the efficiency of the
algorithm, the computational effort required and the rigour of the bounds. The
approach we use has the virtues of being simple and efficient and we present it
in section 3 in a way that is straightforward to implement.
| [
"math.DS",
"math.NT"
] | math.DS | math.NT | Dynamical Systems;Number Theory | 2,326Dynamical Systems;Number Theory
|
2102.06883 | The coronavirus (COVID-19) is currently the most common contagious disease
which is prevalent all over the world. The main challenge of this disease is
the primary diagnosis to prevent secondary infections and its spread from one
person to another. Therefore, it is essential to use an automatic diagnosis
system along with clinical procedures for the rapid diagnosis of COVID-19 to
prevent its spread. Artificial intelligence techniques using computed
tomography (CT) images of the lungs and chest radiography have the potential to
obtain high diagnostic performance for Covid-19 diagnosis. In this study, a
fusion of convolutional neural network (CNN), support vector machine (SVM), and
Sobel filter is proposed to detect COVID-19 using X-ray images. A new X-ray
image dataset was collected and subjected to high pass filter using a Sobel
filter to obtain the edges of the images. Then these images are fed to CNN deep
learning model followed by SVM classifier with ten-fold cross validation
strategy. This method is designed so that it can learn with not many data. Our
results show that the proposed CNN-SVM with Sobel filtering (CNN-SVM+Sobel)
achieved the highest classification accuracy of 99.02% in accurate detection of
COVID-19. It showed that using Sobel filter can improve the performance of CNN.
Unlike most of the other researches, this method does not use a pre-trained
network. We have also validated our developed model using six public databases
and obtained the highest performance. Hence, our developed model is ready for
clinical application
| [
"eess.IV",
"cs.CV"
] | eess.IV | cs.CV | Image and Video Processing;Computer Vision and Pattern Recognition | 3,532Image and Video Processing;Computer Vision and Pattern Recognition
|
2211.16560 | Topological photonic crystals have received considerable attention for their
ability to manipulate and guide light in unique ways. They are typically
designed by hand based on careful analysis of their bands and mode profiles,
but recent theoretical advances have revealed new and powerful insights into
the connection between band symmetry, connectivity, and topology. Here we
propose a combined global and local optimization framework that integrates a
flexible symmetry-constrained level-set parameterization with standard
gradient-free optimization algorithms to optimize topological photonic
crystals, a problem setting where the objective function may be highly
non-convex and non-continuous. Our framework can be applied to any
symmetry-identifiable band topology, and we demonstrate its applicability to
several prominent kinds of three-dimensional band topology, namely
$\Gamma$-enforced nodal lines, Weyl points, and Chern insulators. Requiring no
prior examples of topological photonic crystals or prior knowledge on the
connection between structure and band topology, our approach indicates a path
towards the automated discovery of novel topological photonic crystal designs.
| [
"physics.optics",
"cond-mat.other",
"physics.comp-ph"
] | physics.optics | cond-mat.other | Optics;Other Condensed Matter;Computational Physics | 7,267longtail
|
2103.03612 | As the successor of H.265/HEVC, the new versatile video coding standard
(H.266/VVC) can provide up to 50% bitrate saving with the same subjective
quality, at the cost of increased decoding complexity. To accelerate the
application of the new coding standard, a real-time H.266/VVC software decoder
that can support various platforms is implemented, where SIMD technologies,
parallelism optimization, and the acceleration strategies based on the
characteristics of each coding tool are applied. As the mobile devices have
become an essential carrier for video services nowadays, the mentioned
optimization efforts are not only implemented for the x86 platform, but more
importantly utilized to highly optimize the decoding performance on the ARM
platform in this work. The experimental results show that when running on the
Apple A14 SoC (iPhone 12pro), the average single-thread decoding speed of the
present implementation can achieve 53fps (RA and LB) for full HD (1080p)
bitstreams generated by VTM-11.0 reference software using 8bit Common Test
Conditions (CTC). When multi-threading is enabled, an average of 32 fps (RA)
can be achieved when decoding the 4K bitstreams.
| [
"eess.IV",
"cs.MM"
] | eess.IV | cs.MM | Image and Video Processing;Multimedia | 3,568Image and Video Processing;Multimedia
|
astro-ph/0412606 | I present a simple self-consistent dust spectral energy distribution (SED)
model that has been applied to fit the well-sampled observed UV-to-radio SED of
four nearby starbursting dwarf galaxies. The main originality of this model is
that numerous multi-wavelength observations, from UV to millimeter (mm),
constrain in a self-consistent manner, both the local radiation field and the
grain size distribution. I finally present the results of our model and discuss
the average dust properties in these dwarf galaxies.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2006.15552 | In this work we study type IIB Calabi-Yau orientifold compactifications in
the presence of space-time filling D7-branes and O7-planes. In particular, we
conclude that $\alpha'^2 g_s$-corrections to their DBI actions lead to a
modification of the four-dimensional $\mathcal{N}=1$ K\"ahler potential and
coordinates. We focus on the one-modulus case of the geometric background i.e.
$h^{1,1}=1$ where we find that the $\alpha'^2 g_s$-correction is of topological
nature. It depends on the first Chern form of the four-cycle of the Calabi-Yau
orientifold which is wrapped by the D7-branes and O7-plane. This is in
agreement with our previous F-theory analysis and provides further evidence for
a potential breaking of the no-scale structure at order $\alpha'^2 g_s$.
Corrected background solutions for the dilaton, the warp-factor as well as the
internal space metric are derived. Additionally, we briefly discuss
$\alpha'$-corrections from other D$p$-branes.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2104.02158 | Containerization simplifies the sharing and deployment of applications when
environments change in the software delivery chain. To deploy an application,
container delivery methods push and pull container images. These methods
operate on file and layer (set of files) granularity, and introduce redundant
data within a container. Several container operations such as upgrading,
installing, and maintaining become inefficient, because of copying and
provisioning of redundant data. In this paper, we reestablish recent results
that block-level deduplication reduces the size of individual containers, by
verifying the result using content-defined chunking. Block-level deduplication,
however, does not improve the efficiency of push/pull operations which must
determine the specific blocks to transfer. We introduce a content-defined
Merkle Tree (\CDMT{}) over deduplicated storage in a container. \CDMT{} indexes
deduplicated blocks and determines changes to blocks in logarithmic time on the
client. \CDMT{} efficiently pushes and pulls container images from a registry,
especially as containers are upgraded and (re-)provisioned on a client. We also
describe how a registry can efficiently maintain the \CDMT{} index as new image
versions are pushed. We show the scalability of \CDMT{} over Merkle Trees in
terms of disk and network I/O savings using 15 container images and 233 image
versions from Docker Hub.
| [
"cs.DB"
] | cs.DB | Databases | 1,977Databases
|
|
hep-th/9906044 | This is a thesis/review article that combines some of the results of
hep-th/9809061, hep-th/9810224 and hep-th/9901135 with a short discussion of
introductory background material; an attempt has been made to present the work
in a self-contained manner. The first chapter mostly targets readers who are
vaguely familiar with traditional and contemporary string theory. Chapter two
discusses in detail the thermodynamics of the 0+1 dimensional Super Yang-Mills
(SYM) theory as an illustrative example of the main ideas of the work. The
third chapter outlines the phase structures of p+1 dimensional SYM theories on
tori for 1<=p<=5, and that of the D1D5 system; we avoid presenting the
technical details of the construction of these phase diagrams, focusing instead
on the physics of the final results. The last chapter discusses the dynamics of
the formation of boosted black holes in strongly coupled SYM theory.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
1711.00693 | This paper studies the problem of full reference visual quality assessment of
denoised images with a special emphasis on images with low contrast and
noise-like texture. Denoising of such images together with noise removal often
results in image details loss or smoothing. A new test image database, FLT,
containing 75 noise-free "reference" images and 300 filtered ("distorted")
images is developed. Each reference image, corrupted by an additive white
Gaussian noise, is denoised by the BM3D filter with four different values of
threshold parameter (four levels of noise suppression). After carrying out a
perceptual quality assessment of distorted images, the mean opinion scores
(MOS) are obtained and compared with the values of known full reference quality
metrics. As a result, the Spearman Rank Order Correlation Coefficient (SROCC)
between PSNR values and MOS has a value close to zero, and SROCC between values
of known full-reference image visual quality metrics and MOS does not exceed
0.82 (which is reached by a new visual quality metric proposed in this paper).
The FLT dataset is more complex than earlier datasets used for assessment of
visual quality for image denoising. Thus, it can be effectively used to design
new image visual quality metrics for image denoising.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
2309.12686 | Understanding the evolution of cooperation in structured populations
represented by networks is a problem of long research interest, and a most
fundamental and widespread property of social networks related to cooperation
phenomena is that the node's degree (i.e., number of edges connected to the
node) is heterogeneously distributed. Previous results indicate that static
heterogeneous (i.e., degree-heterogeneous) networks promote cooperation in
stationarity compared to static regular (i.e., degree-homogeneous) networks if
equilibrium dynamics starting from many cooperators and defectors is employed.
However, the above conclusion reverses if we employ non-equilibrium stochastic
processes to measure the fixation probability for cooperation, i.e., the
probability that a single cooperator successfully invades a population. Here we
resolve this conundrum by analyzing the fixation of cooperation on temporal
(i.e., time-varying) networks. We theoretically prove and numerically confirm
that on both synthetic and empirical networks, contrary to the case of static
networks, temporal heterogeneous networks can promote cooperation more than
temporal regular networks in terms of the fixation probability of cooperation.
Given that the same conclusion is known for the equilibrium fraction of
cooperators on temporal networks, the present results provide a unified
understanding of the effect of temporal degree heterogeneity on promoting
cooperation across two main analytical frameworks, i.e., equilibrium and
non-equilibrium ones.
| [
"physics.soc-ph",
"math.DS"
] | physics.soc-ph | math.DS | Physics and Society;Dynamical Systems | 5,499Physics and Society;Dynamical Systems
|
1202.4723 | Interactions of Cn (element 112) atoms with small Au clusters are studied
using accurate ab initio scalar relativistic coupled cluster method for
correlation treatment and two-component relativistic density functional theory
(RDFT) to account for spin-dependent relativistic effect. The results
demonstrate the failure of RDFT with simple generalized-gradient and hybrid
functionals in describing Cn--Au bonds in complex systems.
| [
"physics.chem-ph"
] | physics.chem-ph | Chemical Physics | 859Chemical Physics
|
|
2306.01608 | A set $D$ of vertices is a strong dominating set in a graph $G$, if for every
vertex $x\in V(G) \setminus D$ there is a vertex $y\in D$ with $xy\in E(G)$ and
$deg(x) \leq deg(y)$. The strong domination number $\gamma_{st}(G)$ of $G$ is
the minimum cardinality of a strong dominating set in $G$. Let $G$ be a
connected graph constructed from pairwise disjoint connected graphs $G_1,\ldots
,G_k$ by selecting a vertex of $G_1$, a vertex of $G_2$, and identifying these
two vertices, and thereafter continuing in this manner inductively. The graphs
$G_1,\ldots ,G_k$ are the primary subgraphs of $G$. In this paper, we study the
strong domination number of $K_r$-gluing of two graphs and investigate the
strong domination number for some particular cases of graphs from their primary
subgraphs.
| [
"math.CO"
] | math.CO | Combinatorics | 1,014Combinatorics
|
|
cond-mat/0610495 | The magnetic field dependence of the oxygen-isotope (^{16}O/^{18}O) effect
(OIE) on the in-plane magnetic field penetration depth \lambda_{ab} was studied
in the hole-doped high-temperature cuprate superconductors YBa_2Cu_4O_8,
Y_0.8Pr_0.2Ba_2Cu_3O_7-\delta, and Y_0.7Pr_0.3Ba_2Cu_3O_7-\delta. It was found
that \lambda_ab for the ^{16}O substituted samples increases stronger with
increasing magnetic field than for the ^{18}O ones. The OIE on \lambda_ab
decreases by more than a factor of two with increasing magnetic field from
\mu_0H=0.2 T to \mu_0H=0.6 T. This effect can be explained by the isotope
dependence of the in-plane charge carrier mass m^\ast_{ab}.
| [
"cond-mat.supr-con"
] | cond-mat.supr-con | Superconductivity | 7,066Superconductivity
|
|
1402.5293 | In this paper we examine the interaction of $D N$ and $D^* N$ states,
together with their coupled channels, by using an extension of the local hidden
gauge formalism from the light meson sector, which is based on heavy quark spin
symmetry. The scheme is based on the use of the impulse approximation at the
quark level, with the heavy quarks acting as spectators, which occurs for the
dominant terms where there is the exchange of a light meson. The pion exchange
and the Weinberg-Tomozawa interactions are generalized and with this dynamics
we look for states generated from the interaction, with a unitary coupled
channels approach that mixes the pseudoscalar-baryon and vector-baryon states.
We find two states with nearly zero width which are associated to the
$\Lambda_c(2595)$ and $\Lambda_c(2625)$. The lower state, with $J^P = 1/2^-$,
couples to $D N$ and $D^* N$, and the second one, with $J^P = 3/2^-$, to $D^*
N$. In addition to these two $\Lambda_c$ states, we find four more states with
$I=0$, one of them nearly degenerate in two states of $J=1/2,\ 3/2$.
Furthermore we find three states in $I=1$, two of them degenerate in $J=1/2,
3/2$.
| [
"hep-ph",
"nucl-th"
] | hep-ph | nucl-th | High Energy Physics - Phenomenology;Nuclear Theory | 3,240High Energy Physics - Phenomenology;Nuclear Theory
|
2111.12657 | Entangled photons are pivotal elements in emerging quantum information
technologies. While several schemes are available for the production of
entangled photons, they typically require the assistance of cumbersome optical
elements to couple them to other components involved in logic operations. Here,
we introduce a scheme by which entangled photon pairs are directly generated as
guided mode states in optical waveguides. The scheme relies on the intrinsic
nonlinearity of the waveguide material, circumventing the use of bulky optical
components. Specifically, we consider an optical fiber under normal
illumination, so that photon down-conversion can take place to waveguide states
emitted with opposite momentum into a spectral region populated by only two
accessible modes. By additionally configuring the external illumination to
interfere different incident directions, we can produce maximally entangled
photon-pair states, directly generated as waveguide modes with conversion
efficiencies that are competitive with respect to existing macroscopic schemes.
These results should find application in the design of more efficient and
compact quantum optics devices.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
cond-mat/0603663 | We apply periodic-orbit theory to calculate the integrated density of states
$N(k)$ from the periodic orbits of pseudointegrable polygon and barrier
billiards. We show that the results agree so well with the results obtained
from direct diagonalization of the Schr\"odinger equation, that about the first
100 eigenvalues can be obtained directly from the periodic-orbit calculations
in good accuracy.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
0802.0279 | We remove the need to physically transport computational anyons around each
other from the implementation of computational gates in topological quantum
computing. By using an anyonic analog of quantum state teleportation, we show
how the braiding transformations used to generate computational gates may be
produced through a series of topological charge measurements.
| [
"quant-ph",
"cond-mat.mes-hall",
"hep-th"
] | quant-ph | cond-mat.mes-hall | Quantum Physics;Mesoscale and Nanoscale Physics;High Energy Physics - Theory | 6,123Quantum Physics;Mesoscale and Nanoscale Physics;High Energy Physics - Theory
|
2110.13683 | Constructing large-scaled medical knowledge graphs can significantly boost
healthcare applications for medical surveillance, bring much attention from
recent research. An essential step in constructing large-scale MKG is
extracting information from medical reports. Recently, information extraction
techniques have been proposed and show promising performance in biomedical
information extraction. However, these methods only consider limited types of
entity and relation due to the noisy biomedical text data with complex entity
correlations. Thus, they fail to provide enough information for constructing
MKGs and restrict the downstream applications. To address this issue, we
propose Biomedical Information Extraction, a hybrid neural network to extract
relations from biomedical text and unstructured medical reports. Our model
utilizes a multi-head attention enhanced graph convolutional network to capture
the complex relations and context information while resisting the noise from
the data. We evaluate our model on two major biomedical relationship extraction
tasks, chemical-disease relation and chemical-protein interaction, and a
cross-hospital pan-cancer pathology report corpus. The results show that our
method achieves superior performance than baselines. Furthermore, we evaluate
the applicability of our method under a transfer learning setting and show that
BioIE achieves promising performance in processing medical text from different
formats and writing styles.
| [
"cs.CV",
"cs.AI",
"cs.CL"
] | cs.CV | cs.AI | Computer Vision and Pattern Recognition;Artificial Intelligence;Computation and Language | 1,503Computer Vision and Pattern Recognition;Artificial Intelligence;Computation and Language
|
2006.04668 | In this paper, we decompose the space of nearly holomorphic Hilbert-Siegel
automorphic forms as representations of the adele group under certain
assumptions. We also give an application for classical holomorphic
Hilbert-Siegel modular forms. In particular, we show the surjectivity of the
global Siegel operator for certain congruence subgroups with large weights.
| [
"math.NT",
"math.RT"
] | math.NT | math.RT | Number Theory;Representation Theory | 4,998Number Theory;Representation Theory
|
2112.08867 | 3D-aware image generative modeling aims to generate 3D-consistent images with
explicitly controllable camera poses. Recent works have shown promising results
by training neural radiance field (NeRF) generators on unstructured 2D images,
but still can not generate highly-realistic images with fine details. A
critical reason is that the high memory and computation cost of volumetric
representation learning greatly restricts the number of point samples for
radiance integration during training. Deficient sampling not only limits the
expressive power of the generator to handle fine details but also impedes
effective GAN training due to the noise caused by unstable Monte Carlo
sampling. We propose a novel approach that regulates point sampling and
radiance field learning on 2D manifolds, embodied as a set of learned implicit
surfaces in the 3D volume. For each viewing ray, we calculate ray-surface
intersections and accumulate their radiance generated by the network. By
training and rendering such radiance manifolds, our generator can produce high
quality images with realistic fine details and strong visual 3D consistency.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
cond-mat/0201234 | We show that low-angle grain boundaries (GB) in high-temperature
superconductors exhibit intermediate Abrikosov vortices with Josephson cores,
whose length $l$ along GB is smaller that the London penetration depth, but
larger than the coherence length. We found an exact solution for a periodic
vortex structure moving along GB in a magnetic field $H$ and calculated the
flux flow resistivity $R_F(H)$, and the nonlinear voltage-current
characteristics. The predicted $R_F(H)$ dependence describes well our
experimental data on $7^{\circ}$ unirradiated and irradiated $YBa_2Cu_3O_7$
bicrystals, from which the core size $l(T)$, and the intrinsic depairing
density $J_b(T)$ on nanoscales of few GB dislocations were measured for the
first time. The observed temperature dependence of $J_b(T)=J_{b0}(1-T/T_c)^2$
indicates a significant order parameter suppression in current channels between
GB dislocation cores.
| [
"cond-mat.supr-con"
] | cond-mat.supr-con | Superconductivity | 7,066Superconductivity
|
|
1506.01787 | Using a method of eigenfunction expansion, a stochastic equation is developed
for the generalized Schr{\"o}dinger equation with random fluctuations. The wave
field $ {\psi} $ is expanded in terms of eigenfunctions: $ {\psi} = \sum_{n}
a_{n} (t) {\phi}_{n} (x) $, with $ {\phi}_{n} $ being the eigenfunction that
satisfies the eigenvalue equation $ H_{0} {\phi}_{n} = {\lambda}_{n} {\phi}_{n}
$, where $ H_{0} $ is the reference "Hamiltonian" conventionally called
"unperturbed" Hamiltonian. The Langevin equation is derived for the expansion
coefficient $ a_{n} (t) $, and it is converted to the Fokker--Planck (FP)
equation for a set $ \{ a_{n} \} $ under the assumption of the Gaussian white
noise for the fluctuation. This procedure is carried out by a functional
integral, in which the functional Jacobian plays a crucial role for determining
the form of the FP equation. The analyses are given for the FP equation by
adopting several approximate schemes.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
nucl-ex/0702045 | A Large Ion Collider Experiment - ALICE will become operational with the
startup of the Large Hadron Collider - LHC at the end of 2007. One focus of the
physics program is the measurement of quarkonia in proton-proton and lead-lead
collisions. Quarkonia states will be measured in two kinematic regions and
channels: di-muonic decays will be measured in the forward region by the muon
arm, the central part of the detector will measure di-electronic decays. The
presented studies show the expected performance of the di-electron measurement
in proton-proton and central lead-lead collisions.
| [
"nucl-ex"
] | nucl-ex | Nuclear Experiment | 4,855Nuclear Experiment
|
|
2305.15669 | Offline-to-online reinforcement learning (RL), by combining the benefits of
offline pretraining and online finetuning, promises enhanced sample efficiency
and policy performance. However, existing methods, effective as they are,
suffer from suboptimal performance, limited adaptability, and unsatisfactory
computational efficiency. We propose a novel framework, PROTO, which overcomes
the aforementioned limitations by augmenting the standard RL objective with an
iteratively evolving regularization term. Performing a trust-region-style
update, PROTO yields stable initial finetuning and optimal final performance by
gradually evolving the regularization term to relax the constraint strength. By
adjusting only a few lines of code, PROTO can bridge any offline policy
pretraining and standard off-policy RL finetuning to form a powerful
offline-to-online RL pathway, birthing great adaptability to diverse methods.
Simple yet elegant, PROTO imposes minimal additional computation and enables
highly efficient online finetuning. Extensive experiments demonstrate that
PROTO achieves superior performance over SOTA baselines, offering an adaptable
and efficient offline-to-online RL framework.
| [
"cs.LG",
"cs.AI",
"cs.RO"
] | cs.LG | cs.AI | Machine Learning;Artificial Intelligence;Robotics | 3,980Machine Learning;Artificial Intelligence;Robotics
|
1604.06732 | Previously we considered the effect of experimental parameters on optimized
transmission through opaque media using spatial light modulator (SLM)-based
wavefront shaping. In this study we consider the opposite geometry, in which we
optimize reflection from an opaque surface such that the backscattered light is
focused onto a spot on an imaging detector. By systematically varying different
experimental parameters (genetic algorithm iterations, bin size, SLM active
area, target area, spot size, and sample angle with respect to the optical
axis) and optimizing the reflected light we determine how each parameter
affects the intensity enhancement. We find that the effects of the experimental
parameters on the enhancement are similar to those measured for a transmissive
geometry, but with the exact functional forms changed due to the different
geometry and the use of a genetic algorithm instead of an iterative algorithm.
Additionally, we find preliminary evidence of greater enhancements than
predicted by random matrix theory, suggesting a possibly new physical mechanism
to be investigated in future work.
| [
"physics.optics"
] | physics.optics | Optics | 5,146Optics
|
|
1802.03624 | These are lecture notes prepared for the summer school "Geometric, algebraic
and topological methods in quantum field theory", held in Villa de Leyva in
July 2017. Our goal is to provide an introduction to a conjecture of Chern that
states that the Euler characteristic of a closed affine manifold vanishes. We
present part of the history and motivation for the conjecture as well as some
recent developments. All comments and corrections are most welcome!
| [
"math.DG",
"math.AT"
] | math.DG | math.AT | Differential Geometry;Algebraic Topology | 2,019Differential Geometry;Algebraic Topology
|
2010.13718 | Attosecond transient absorption spectroscopy (ATAS) is used to observe
photoexcited dynamics with outstanding time resolution. The main experimental
challenge of this technique is that high-harmonic generation sources show
significant instabilities, resulting in sub-par sensitivity when compared to
other techniques. This paper proposes edge-pixel referencing as a means to
suppress this noise. Two approaches are introduced: the first is deterministic
and uses a correlation analysis, while the second relies on singular value
decomposition. Each methods is demonstrated and quantified on a noisy
measurement taken on $\text{WS}_2$ and results in a fivefold increase in
sensitivity. The combination of the two methods ensures the fidelity of the
procedure and can be implemented on live data collection but also on existing
datasets. The results show that edge-referencing methods bring the sensitivity
of ATAS near the detector noise floor. An implementation of the post-processing
code is provided to the reader.
| [
"physics.optics",
"physics.data-an",
"physics.ins-det"
] | physics.optics | physics.data-an | Optics;Data Analysis, Statistics and Probability;Instrumentation and Detectors | 7,267longtail
|
0712.3124 | I present a simplified model for the gluon Green's function governing
high-energy QCD dynamics, in arbitrary space-time dimensions. The BFKL integral
equation (either with or without running coupling) reduces to a second order
differential equation that can be solved in terms of Bessel and hypergeometric
functions. Explicit expressions for the gluon density and its anomalous
dimension are derived in MS and Q_0 factorization schemes. This analysis
illustrates the qualitative features of the QCD gluon density in both
factorization schemes. In addition, it clarifies the mathematical properties
and validates the results of the ``gamma-representation'' method proposed by
M.Ciafaloni and myself for extracting resummed next-to-leading-log x anomalous
dimensions of phenomenological relevance in the two schemes.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2002.03737 | Deep convolutional neural networks (CNN) always depend on wider receptive
field (RF) and more complex non-linearity to achieve state-of-the-art
performance, while suffering the increased difficult to interpret how relevant
patches contribute the final prediction. In this paper, we construct an
interpretable AnchorNet equipped with our carefully designed RFs and linearly
spatial aggregation to provide patch-wise interpretability of the input media
meanwhile localizing multi-scale informative patches only supervised on
media-level labels without any extra bounding box annotations. Visualization of
localized informative image and text patches show the superior multi-scale
localization capability of AnchorNet. We further use localized patches for
downstream classification tasks across widely applied networks. Experimental
results demonstrate that replacing the original inputs with their patches for
classification can get a clear inference acceleration with only tiny
performance degradation, which proves that localized patches can indeed retain
the most semantics and evidences of the original inputs.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
2007.01286 | We investigate the crossover of the entanglement entropy towards its thermal
value in nearly integrable systems. We employ equation of motion techniques to
study the entanglement dynamics in a lattice model of weakly interacting
spinless fermions after a quantum quench. For weak enough interactions we
observe a two-step relaxation of the entanglement entropies of finite
subsystems. Initially the entropies follow a nearly integrable evolution,
approaching the value predicted by the Generalized Gibbs Ensemble (GGE) of the
unperturbed model. Then, they start a slow drift towards the thermal stationary
value described by a standard Gibbs Ensemble (GE). While the initial relaxation
to the GGE is independent of the interaction, the slow drift from GGE to GE
values happens on time scales proportional to the inverse interaction squared.
For asymptotically large times and subsystem sizes the dynamics of the
entropies can be predicted using a modified quasiparticle picture that keeps
track of the evolution of the fermionic occupations caused by the integrability
breaking. This picture gives a quantitative description of the results as long
as the integrability-breaking timescale is much larger than the one associated
with the (quasi) saturation to the GGE. In the opposite limit the quasiparticle
picture still provides the correct late-time behaviour, but it underestimates
the initial slope of the entanglement entropy.
| [
"cond-mat.stat-mech",
"cond-mat.str-el",
"quant-ph"
] | cond-mat.stat-mech | cond-mat.str-el | Statistical Mechanics;Strongly Correlated Electrons;Quantum Physics | 6,974Statistical Mechanics;Strongly Correlated Electrons;Quantum Physics
|
1709.06795 | We map the phase-space trajectories of an external-cavity semiconductor laser
using phase portraits. This is both a visualization tool as well as a
thoroughly quantitative approach enabling unprecedented insight into the
dynamical regimes, from continuous-wave through coherence collapse as feedback
is increased. Namely, the phase portraits in the intensity versus laser-diode
terminal-voltage (serving as a surrogate for inversion) plane are mapped out.
We observe a route to chaos interrupted by two types of limit cycles, a
subharmonic regime and period-doubled dynamics at the edge of chaos. The
transition of the dynamics are analyzed utilizing bifurcation diagrams for both
the optical intensity and the laser-diode terminal voltage. These observations
provide visual insight into the dynamics in these systems.
| [
"nlin.CD"
] | nlin.CD | Chaotic Dynamics | 810Chaotic Dynamics
|
|
1811.12468 | We investigate the effect on survival and coexistence of introducing forest
fire epidemics to a certain two-species competition model. The model is an
extension of the one introduced by Durrett and Remenik [DR09], who studied a
discrete time particle system running on a random 3-regular graph where
occupied sites grow until they become sufficiently dense so that an epidemic
wipes out large clusters. In our extension we let two species affected by
independent epidemics compete for space, and we allow the epidemic to attack
not only giant clusters, but also clusters of smaller order. Our main results
show that, for the two-type model, there are explicit parameter regions where
either one species dominates or there is coexistence; this contrasts with the
behavior of the model without epidemics, where the fitter species always
dominates. We also discuss the survival and extinction regimes for the model
with a single species. In both cases we prove convergence to explicit dynamical
systems; simulations suggest that their orbits present chaotic behavior.
| [
"math.PR"
] | math.PR | Probability | 5,709Probability
|
|
2211.03490 | This work focuses on the problem of detection and prevention of stolen and
misused secrets (such as private keys) for authentication toward centralized
services. We propose a solution for such a problem based on the
blockchain-based two-factor authentication scheme SmartOTPs, which we modify
for our purposes and utilize in the setting of two and half-factor
authentication against a centralized service provider. Our proposed solution
consists of four entities that interact together to ensure authentication: (1)
the user, (2) the authenticator, (3) the service provider, and (4) the smart
contract. Out of two and a half factors of our solution, the first factor
stands for the private key, and the second and a half factor stands for
one-time passwords (OTPs) and their precursors, where OTPs are obtained from
the precursors (a.k.a., pre-images) by cryptographically secure hashing. We
describe the protocol for bootstrapping our approach as well as the
authentication procedure. We make the security analysis of our solution, where
on top of the main attacker model that steals secrets from the client, we
analyze man-in-the-middle attacks and malware tampering with the client. In the
case of stolen credentials, we show that our solution enables the user to
immediately detect the attack occurrence and proceed to re-initialization with
fresh credentials.
| [
"cs.CR"
] | cs.CR | Cryptography and Security | 1,782Cryptography and Security
|
|
1612.02875 | We propose a distributed computing framework, based on a divide and conquer
strategy and hierarchical modeling, to accelerate posterior inference for
high-dimensional Bayesian factor models. Our approach distributes the task of
high-dimensional covariance matrix estimation to multiple cores, solves each
subproblem separately via a latent factor model, and then combines these
estimates to produce a global estimate of the covariance matrix. Existing
divide and conquer methods focus exclusively on dividing the total number of
observations $n$ into subsamples while keeping the dimension $p$ fixed. Our
approach is novel in this regard: it includes all of the $n$ samples in each
subproblem and, instead, splits the dimension $p$ into smaller subsets for each
subproblem. The subproblems themselves can be challenging to solve when $p$ is
large due to the dependencies across dimensions. To circumvent this issue, we
specify a novel hierarchical structure on the latent factors that allows for
flexible dependencies across dimensions, while still maintaining computational
efficiency. Our approach is readily parallelizable and is shown to have
computational efficiency of several orders of magnitude in comparison to
fitting a full factor model. We report the performance of our method in
synthetic examples and a genomics application.
| [
"stat.ME"
] | stat.ME | Methodology | 4,557Methodology
|
|
2010.02933 | Superstring/M-theory compactified on compact Ricci flat manifolds have
recently been conjectured to exhibit instabilities whenever the metrics do not
have special holonomy. We use worldsheet conformal field theory to investigate
instabilities of Type II superstring theories on compact, Ricci flat, spin
3-manifolds including a worldsheet description of their spin structures. The
instabilities are signalled by the appearance of stringy tachyons at small
radius and a negative (1-loop) vacuum energy density at large radius. We
briefly discuss the extension to higher dimensions.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
0807.2777 | We develop a theoretical framework that allows us to compare electromagnetism
and gravitation in a fully covariant way. This new scenario does not rely on
any kind of approximation nor associate objects with different operational
meaning as it's sometime done in the literature. We construct the
electromagnetic analogue to the Riemann and Weyl tensors and develop the
equations of motion for these objects. In particular, we are able to identify
precisely how and in what conditions gravity can be mapped to electrodynamics.
As a consequence, many of the gemometrical tools of General Relativity can be
applied to Electromagnetism and vice-versa. We hope our results would shed new
light in the nature of electromagnetic and gravitational theories.
| [
"gr-qc"
] | gr-qc | General Relativity and Quantum Cosmology | 2,674General Relativity and Quantum Cosmology
|
|
2210.07308 | The crisis caused by the COVID-19 outbreak around the globe raised an
increasing concern about the ongoing emergence of variants of SARS-CoV-2 that
may evade the immune response provided by vaccines. New variants appear due to
mutation, and as the cases accumulate, the probability of the emergence of a
variant of concern increases. In this article, we propose a modified SIR model
with waning immunity that captures the competition of two strain classes of an
infectious disease under the effect of vaccination with a highly contagious and
deadly strain class emerging from a prior strain due to mutation. When these
strains compete for a limited supply of susceptible individuals, changes in the
efficiency of vaccines may affect the behaviour of the disease in a non-trivial
way, resulting in complex outcomes. We characterise the parameter space
including intrinsic parameters of the disease, and using the vaccine
efficiencies as control variables. We find different types of transcritical
bifurcations between endemic fixed points and a disease-free equilibrium and
identify a region of strain competition where the two strain classes coexist
during a transient period. We show that a strain can be extinguished either due
to strain competition or vaccination, and we obtain the critical values of the
efficiency of vaccines to eradicate the disease. Numerical studies using
parameters estimated from publicly reported data agree with our theoretical
results. Our mathematical model could be a tool to assess quantitatively the
vaccination policies of competing and emerging strains using the dynamics in
epidemics of infectious diseases.
| [
"q-bio.PE",
"nlin.CD",
"physics.soc-ph"
] | q-bio.PE | nlin.CD | Populations and Evolution;Chaotic Dynamics;Physics and Society | 7,267longtail
|
2107.06604 | Inhomogeneous superconductivity in the high quality single crystals of ZrB12
(Tc = 6 K) has been studied using the heat capacity and x-ray diffraction (XRD)
data. Evidence of two-band superconductivity with two branches of upper
critical field Hc2(Tc) is obtained in a magnetic field applied along the [110]
axis of the crystal. On the contrary, at H //[100], the only dependence Hc2(Tc)
is observed. This finding is supplemented with the checkerboard-type patterns
of the charge stripes in ZrB12 deduced from the detailed analysis of XRD data.
These patterns are compared to the structure of the charge stripes in the
weakly bound superconductor LuB12, whose Tc is 15 times lower than that of
ZrB12. Probable nature of the two-gap superconductivity in ZrB12 with strongly
enhanced characteristics is discussed.
| [
"cond-mat.supr-con"
] | cond-mat.supr-con | Superconductivity | 7,066Superconductivity
|
|
1901.05333 | An experiment on the propagation of flexural-gravity waves was performed in
the HSVA ice tank. Physical characteristics of the water-ice system were
measured in different locations in the tank during the tests, with a number of
sensors deployed in the water, on the ice and in the air. Water velocity was
measured with an acoustic doppler velocimeter (ADV) and an acoustic doppler
current profiler (ADCP); wave amplitudes were measured with ultrasonic sensors
and the optical system Qualisys; in-plane deformations of the ice and the
temperature of the ice and water were measured by fiber optic sensors, and
acoustic emissions were recorded with compressional crystal sensors. All
together 61 tests were performed, with ice thicknesses of 3 cm and 5 cm. The
experimental setup and selected results of the tests are discussed in this
paper. We show that cyclic motion of the ice along the tank, imitating ice
drift, causes an increase in wave damping. We also show that the formation of
non-through cracks in the ice, caused by the action of waves, increases wave
damping.
| [
"physics.ao-ph"
] | physics.ao-ph | Atmospheric and Oceanic Physics | 543Atmospheric and Oceanic Physics
|
|
2002.03630 | The `no-hair' conjecture claims that for a spherically symmetric black hole,
only the information regarding the mass and charge of the black hole is
available to an external observer. However, there are numerous counterexamples
to the `no-hair' conjecture. In this work, we consider a particular
counter-example to the `no-hair' conjecture in (3+1) dimensions, namely, a
static spherically symmetric charged black hole with a scalar hair. We provide
semi-analytic bounds on the greybody factors and study the sparsity of Hawking
radiation of mass-less uncharged scalar fields. Our results show that the
scalar and electric charges contribute oppositely to the greybody factor and
the sparsity of the Hawking radiation cascade. Also, the greybody factor
decreases and the Hawking emission spectra become more sparse with the
reduction in the black hole (ADM) mass.
| [
"gr-qc",
"hep-th"
] | gr-qc | hep-th | General Relativity and Quantum Cosmology;High Energy Physics - Theory | 2,746General Relativity and Quantum Cosmology;High Energy Physics - Theory
|
2304.01817 | A relativistic Hartree-Fock Lagrangian including a chiral potential and
nucleon polarisation is investigated in hopes of providing a better description
of dense nuclear matter. We fully consider the contribution of the exchange
Fock term to the energy and the self-energies, and in addition we investigate
the nucleon's compositeness and finite size effects (confinement and form
factors) and short range correlations modeled by a Jastrow ansatz. These
effects are added step by step, such that their impact on the dense matter
properties can be analysed in details. The parameters of the model are adjusted
to reproduce fundamental properties related to the QCD theory at low energy,
such as the chiral symmetry breaking, nucleon's quark substructure and
Lattice-QCD predictions, as well as two empirical properties at saturation: the
binding energy and the density. All other empirical parameters, e.g., symmetry
energy and its slope, incompressibility modulus, effective mass, as well as
spin-isospin Landau-Midgal parameter are predictions of the models and can be
used to evaluate the gain of the different approximation schemes in describing
nuclear properties. Bayesian statistics is employed in order to propagate
parameter uncertainties into predictions for the nuclear matter properties. We
show that the splitting of the effective Landau mass is largely influenced by
the value of the $\rho^T$ coupling, and we show that the fit to the symmetry
energy, which induces an increase of the coupling constant $g_\rho$ by about
20-25% compared to the case where it is fixed by the quark model, provides a
very good EoS compatible with the present nuclear physics knowledge.
| [
"nucl-th"
] | nucl-th | Nuclear Theory | 4,876Nuclear Theory
|
|
2010.00518 | Tailings ponds are places for storing industrial waste. Once the tailings
pond collapses, the villages nearby will be destroyed and the harmful chemicals
will cause serious environmental pollution. There is an urgent need for a
reliable forecast model, which could investigate the variation trend of
stability coefficient of tailing dam and issue early warnings. In order to fill
the gap, this work presents an hybrid network - Wavelet-based Long-Short-Term
Memory (LSTM) and Convolutional Neural Network (CNN), namely Wavelet-CNN-LSTM
netwrok for predicting the tailings pond risk. Firstly, we construct the
especial nonlinear data processing method to impute the missing value with the
numerical inversion (NI) method, which combines correlation analysis,
sensitivity analysis, and Random Forest (RF) algorithms. Secondly, a new
forecasting model was proposed to monitor the saturation line, which is the
lifeline of the tailings pond and can directly reflect the stability of the
tailings pond. After using the discrete wavelet transform (DWT) to decompose
the original saturation line data into 4-layer wavelets and de-noise the data,
the CNN was used to identify and learn the spatial structures in the time
series, followed by LSTM cells for detecting the long-short-term dependence.
Finally, different experiments were conducted to evaluate the effectiveness of
our model by comparing it with other state-of-the-art algorithms. The results
show that Wavelet-CNN-LSTM achieves the best score both in mean absolute
percentage error (MAPE), root-mean-square error (RMSE) and R 2 .
| [
"eess.SP"
] | eess.SP | Signal Processing | 6,402Signal Processing
|
|
1801.03039 | In this paper a novel biclustering algorithm based on artificial intelligence
(AI) is introduced. The method called EBIC aims to detect biologically
meaningful, order-preserving patterns in complex data. The proposed algorithm
is probably the first one capable of discovering with accuracy exceeding 50%
multiple complex patterns in real gene expression datasets. It is also one of
the very few biclustering methods designed for parallel environments with
multiple graphics processing units (GPUs). We demonstrate that EBIC outperforms
state-of-the-art biclustering methods, in terms of recovery and relevance, on
both synthetic and genetic datasets. EBIC also yields results over 12 times
faster than the most accurate reference algorithms. The proposed algorithm is
anticipated to be added to the repertoire of unsupervised machine learning
algorithms for the analysis of datasets, including those from large-scale
genomic studies.
| [
"cs.LG",
"cs.CV",
"cs.IR",
"q-bio.GN"
] | cs.LG | cs.CV | Machine Learning;Computer Vision and Pattern Recognition;Information Retrieval;Genomics | 7,267longtail
|
2102.07601 | Collaborative filtering (CF) has achieved great success in the field of
recommender systems. In recent years, many novel CF models, particularly those
based on deep learning or graph techniques, have been proposed for a variety of
recommendation tasks, such as rating prediction and item ranking. These newly
published models usually demonstrate their performance in comparison to
baselines or existing models in terms of accuracy improvements. However, others
have pointed out that many newly proposed models are not as strong as expected
and are outperformed by very simple baselines.
This paper proposes a simple linear model based on Matrix Factorization (MF),
called UserReg, which regularizes users' latent representations with explicit
feedback information for rating prediction. We compare the effectiveness of
UserReg with three linear CF models that are widely-used as baselines, and with
a set of recently proposed complex models that are based on deep learning or
graph techniques. Experimental results show that UserReg achieves overall
better performance than the fine-tuned baselines considered and is highly
competitive when compared with other recently proposed models. We conclude that
UserReg can be used as a strong baseline for future CF research.
| [
"cs.IR",
"cs.LG"
] | cs.IR | cs.LG | Information Retrieval;Machine Learning | 3,610Information Retrieval;Machine Learning
|
2206.10185 | Since reinforcement learning algorithms are notoriously data-intensive, the
task of sampling observations from the environment is usually split across
multiple agents. However, transferring these observations from the agents to a
central location can be prohibitively expensive in terms of the communication
cost, and it can also compromise the privacy of each agent's local behavior
policy. In this paper, we consider a federated reinforcement learning framework
where multiple agents collaboratively learn a global model, without sharing
their individual data and policies. Each agent maintains a local copy of the
model and updates it using locally sampled data. Although having N agents
enables the sampling of N times more data, it is not clear if it leads to
proportional convergence speedup. We propose federated versions of on-policy
TD, off-policy TD and Q-learning, and analyze their convergence. For all these
algorithms, to the best of our knowledge, we are the first to consider
Markovian noise and multiple local updates, and prove a linear convergence
speedup with respect to the number of agents. To obtain these results, we show
that federated TD and Q-learning are special cases of a general framework for
federated stochastic approximation with Markovian noise, and we leverage this
framework to provide a unified convergence analysis that applies to all the
algorithms.
| [
"cs.LG"
] | cs.LG | Machine Learning | 3,882Machine Learning
|
|
1210.0628 | Mathematical mean-field approaches have been used in many fields, not only in
Physics and Chemistry, but also recently in Finance, Economics, and Game
Theory. In this paper we will study a new special mean-field problem in a
purely probabilistic method, to characterize its limit which is the solution of
mean-field backward stochastic differential equations (BSDEs) with reflections.
On the other hand, we will prove that this type of reflected mean-field BSDEs
can also be obtained as the limit equation of the mean-field BSDEs by
penalization method. Finally, we give the probabilistic interpretation of the
nonlinear and nonlocal partial differential equations with the obstacles by the
solutions of reflected mean-field BSDEs.
| [
"math.PR",
"math.AP"
] | math.PR | math.AP | Probability;Analysis of PDEs | 5,713Probability;Analysis of PDEs
|
2108.11511 | The hydroxyl radical is the primary reactive oxygen species produced by the
radiolysis of water, and is a significant source of radiation damage to living
organisms. Mobility of the hydroxyl radical at low temperatures and/or high
pressures is hence a potentially important factor in determining the challenges
facing psychrophilic and/or barophilic organisms in high-radiation environments
(e.g., ice-interface or undersea environments in which radiative heating is a
potential heat and energy source). Here, we estimate the diffusion coefficient
for the hydroxyl radical in aqueous solution, using a hierarchical Bayesian
model based on atomistic molecular dynamics trajectories in TIP4P/2005 water
over a range of temperatures and pressures.
| [
"stat.AP",
"physics.chem-ph"
] | stat.AP | physics.chem-ph | Applications;Chemical Physics | 7,267longtail
|
0905.4869 | LHCb is the dedicated B physics experiment at the LHC and is due to start
data taking later this year. Its goal is to search for new physics in very rare
processes and make precision measurements of CP violation in B decays. The CKM
angle gamma plays an important role in flavour physics in the Standard Model.
LHCb will exploit the large variety of B hadrons produced by the 14 TeV pp
collisions, performing gamma measurements to the precision of a few degrees.
Here, we will present a summary of the expected gamma sensitivities LHCb will
reach during its first years of data taking, with contributions from several
strategies in both tree and loop processes.
| [
"hep-ex"
] | hep-ex | High Energy Physics - Experiment | 3,059High Energy Physics - Experiment
|
|
gr-qc/9801051 | The relation between microscopic and macroscopic entities in the generally
covariant theories is considered, and it is argued that a sensible definition
of the macroscopic averages requires a restriction of the allowed
transformations of coordinates. Spacetime averages of the geometric objects of
Einstein's unified field theory are then defined, and the reconstruction of
some features of macroscopic reality from hypothetic microscopic structures is
attempted. It is shown how a fluctuating microscopic behaviour of the metric
field can rule the constitutive relation for electromagnetism both in vacuo and
in nondispersive material media. Moreover, if both the metric and the skew
tensor density that represents the electric displacement and the magnetic field
are assumed to possess a wavy microscopic structure, nonvanishing generalized
force densities can appear in the continuum. They originate from a resonance
process, in which at least three waves need to be involved. This process only
occurs if the wavevectors fulfil the three-wave resonance condition, so
ubiquitous in quantum physics. The wavy behaviour of the metric is essential
for the occurrence of this resonance phenomenon.
| [
"gr-qc"
] | gr-qc | General Relativity and Quantum Cosmology | 2,674General Relativity and Quantum Cosmology
|
|
2101.00716 | The problem of finding pure strategy Nash equilibria in multiagent concurrent
games with finite-horizon temporal goals has received some recent attention.
Earlier work solved this problem through the use of Rabin automata. In this
work, we take advantage of the finite-horizon nature of the agents' goals and
show that checking for and finding pure strategy Nash equilibria can be done
using a combination of safety games and lasso testing in B\"uchi automata. To
separate strategic reasoning from temporal reasoning, we model agents' goals by
deterministic finite-word automata (DFAs), since finite-horizon logics such as
LTL\textsubscript{f} and LDL\textsubscript{f} are reasoned about through
conversion to equivalent DFAs. This allow us characterize the complexity of the
problem as PSPACE complete.
| [
"cs.GT"
] | cs.GT | Computer Science and Game Theory | 1,449Computer Science and Game Theory
|
|
1503.00865 | Let $K$ be an uncountable compact metric space and let $C(K,\mathbb{R}^d)$
denote the set of continuous maps $f\colon K \to \mathbb{R}^d$ endowed with the
maximum norm. The goal of this paper is to determine various fractal dimensions
of the graph of the prevalent $f\in C(K,\mathbb{R}^d)$.
As the main result of the paper we show that if $K$ has finitely many
isolated points then the lower and upper box dimension of the graph of the
prevalent $f\in C(K,\mathbb{R}^d)$ are $\underline{\dim}_B K+d$ and
$\overline{\dim}_B K+d$, respectively. This generalizes a theorem of Gruslys,
Jonu\v{s}as, Mijovi\`c, Ng, Olsen, and Petrykiewicz.
We prove that the graph of the prevalent $f\in C(K,\mathbb{R}^d)$ has packing
dimension $\dim_P K+d$, generalizing a result of Balka, Darji, and Elekes.
Balka, Darji, and Elekes proved that the Hausdorff dimension of the graph of
the prevalent $f\in C(K,\mathbb{R}^d)$ equals $\dim_H K+d$. We give a simpler
proof for this statement based on a method of Fraser and Hyde.
| [
"math.CA",
"math.MG",
"math.PR"
] | math.CA | math.MG | Classical Analysis and ODEs;Metric Geometry;Probability | 7,267longtail
|
1601.02750 | Quantum correlations including entanglement and quantum discord has drawn
much attention in characterizing quantum phase transitions. Quantum deficit
originates in questions regarding work extraction from quantum systems coupled
to a heat bath [Phys. Rev. Lett. 89, 180402 (2002)]. It links quantum
thermodynamics with quantum correlations and provides a new standpoint for
understanding quantum non-locality. In this paper, we evaluate the one-way
deficit of two adjacent spins in the bulk for the XX model. In the
thermodynamic limit, the XX model undergoes a first order transition from fully
polarized to a critical phase with quasi-long-range order with decrease of
quantum parameter. We find that the one-way deficit becomes nonzero after the
critical point. Therefore, the one-way deficit characterizes the quantum phase
transition in the XX model.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
2106.15868 | Navigating the world is a fundamental ability for any living entity.
Accomplishing the same degree of freedom in technology has proven to be
difficult. The brain is the only known mechanism capable of voluntary
navigation, making neuroscience our best source of inspiration toward autonomy.
Assuming that state representation is key, we explore the difference in how the
brain and the machine represent the navigational state. Where Reinforcement
Learning (RL) requires a monolithic state representation in accordance with the
Markov property, Neural Representation of Euclidean Space (NRES) reflects
navigational state via distributed activation patterns. We show how
NRES-Oriented RL (neoRL) agents are possible before verifying our theoretical
findings by experiments. Ultimately, neoRL agents are capable of behavior
synthesis across state spaces -- allowing for decomposition of the problem into
smaller spaces, alleviating the curse of dimensionality.
| [
"cs.RO",
"cs.AI"
] | cs.RO | cs.AI | Robotics;Artificial Intelligence | 6,329Robotics;Artificial Intelligence
|
astro-ph/0310259 | We calculate the thermal structure and quiescent thermal luminosity of
accreting neutron stars (warmed by deep crustal heating in accreted matter) in
soft X-ray transients (SXTs). We consider neutron stars with nucleon and
hyperon cores and with accreted envelopes. It is assumed that an envelope has
an outer helium layer (of variable depth) and deeper layers of heavier
elements, either with iron or with much heavier nuclei (of atomic weight A >
100) on the top (Haensel & Zdunik 1990, 2003, astro-ph/0305220). The relation
between the internal and surface stellar temperatures is obtained and fitted.
The quiescent luminosity of the hottest (low-mass) and coldest (high-mass)
neutron stars is calculated, together with the ranges of its possible
variations due to variable thickness of the helium layer. The results are
compared with observations of SXTs, particularly, containing the coldest (SAX
J1808.4-3658) and the hottest (Aql X-1) neutron stars. The observations of SAX
J1808.4-3658 in a quiescent state on March 24, 2001 (Campana et al. 2002,
astro-ph/0206376) can be explained only if this SXT contains a massive neutron
star with a nucleon/hyperon core; a hyperon core with a not too low fraction of
electrons is preferable. Future observations may discriminate between the
various models of hyperon/nucleon dense matter. The thermal emission of SAX
J1808.4-3658 is also sensitive to the models of plasma ionization in the
outermost surface layers and can serve for testing such models.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2008.08406 | We consider the equation $\Delta_x u+u_{yy}+f(u)=0,\
x=(x_1,\dots,x_N)\in\mathbb{R}^N,\ y\in \mathbb{R},$ where $N\geq 2$ and $f$ is
a sufficiently smooth function satisfying $f(0)=0$, $f'(0)<0$, and some natural
additional conditions. We prove that the equation possesses uncountably many
positive solutions (disregarding translations) which are radially symmetric in
$x'=(x_1,\dots,x_{N-1})$ and decaying as $|x'|\to\infty$, periodic in $x_N$,
and quasiperiodic in $y$. Related theorems for more general equations are
included in our analysis as well. Our method is based on center manifold and
KAM-type results.
| [
"math.AP",
"math.DS"
] | math.AP | math.DS | Analysis of PDEs;Dynamical Systems | 231Analysis of PDEs;Dynamical Systems
|
2302.13307 | This paper presents a convex-QCQP based novel path planning algorithm named
ellipsoidal constrained agent navigation (ECAN), for a challenging problem of
online path planning in completely unknown and unseen continuous environments.
ECAN plans path for the agent by making a tunnel of overlapping ellipsoids, in
an online fashion, through the environment. Convex constraints in the
ellipsoid-formation step circumvent collision with the obstacles. The problem
of online-tunneling is solved as a convex-QCQP. This paper assumes no
constraints on shape of the agent and the obstacles. However, to make the
approach clearer, this paper first introduces the framework for a point-mass
agent with point-size obstacles. After explaining the underlying principle in
drawing an ellipsoid tunnel, the framework is extended to the agent and
obstacles having finite area (2d space) and finite-volume (3d-space).
| [
"cs.RO",
"cs.AI"
] | cs.RO | cs.AI | Robotics;Artificial Intelligence | 6,329Robotics;Artificial Intelligence
|
hep-ph/0605296 | We systematically study the possibility of determining the spin of new
particles after their discovery at the LHC. We concentrate on angular
correlations in cascade decays. Motivated by constraints of electroweak
precision tests and the potential of providing a Cold Dark Matter candidate, we
focus on scenarios of new physics in which some discrete symmetry guarantees
the existence of stable neutral particles which escape the detector. More
specifically, we compare supersymmetry with another generic scenario in which
new physics particles have the same spin as their Standard Model partners. A
survey of possibilities of observing spin correlations in a broad range of
decay channels is carried out, with interesting ones identified. Rather than
confining ourselves to one "collider friendly" benchmark point (such as SPS1a),
we describe the parameter region in which any particular decay channel is
effective. We conduct a more detailed study of chargino's spin determination in
the decay channel $\tilde{q}\to q + \tilde{C}^\pm \to q + W^\pm + LSP$. A scan
over the chargino and neutralino masses is performed. We find that as long as
the spectrum is not too degenerate the prospects for spin determination in this
channel are rather good.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
hep-ph/0603161 | Filon-Simpson quadrature rules are derived for integrals of the type \int_a^b
dx f(x) sin(xy)/(xy) and \int_a^b dx f(x) 4 sin^2(xy/2)/(xy)^2 which are needed
in applications of the worldline variational approach to Quantum Field Theory.
These new integration rules reduce to the standard Simpson rule for y = 0 and
are exact for y \to \infty when a = 0 and f(0) \ne 0.The subleading term in the
asymptotic expansion is also reproduced more and more precisely when the number
of integration points is increased. Tests show that the numerical results are
indeed stable over a wide range of y-values whereas usual Gauss-Legendre
quadrature rules are more precise at low y but fail completely for large values
of y. The associated Filon-Simpson weights are given in terms of sine and
cosine integrals and have to be evaluated for each value of y. A Fortran
program to calculate them in a fast and accurate manner is available. A
detailed comparison with the double exponential method of Ooura and Mori is
made.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2309.03202 | This work seeks to answer key research questions regarding the viability of
reinforcement learning over the S&P 500 index. The on-policy techniques of
Value Iteration (VI) and State-action-reward-state-action (SARSA) are
implemented along with the off-policy technique of Q-Learning. The models are
trained and tested on a dataset comprising multiple years of stock market data
from 2000-2023. The analysis presents the results and findings from training
and testing the models using two different time periods: one including the
COVID-19 pandemic years and one excluding them. The results indicate that
including market data from the COVID-19 period in the training dataset leads to
superior performance compared to the baseline strategies. During testing, the
on-policy approaches (VI and SARSA) outperform Q-learning, highlighting the
influence of bias-variance tradeoff and the generalization capabilities of
simpler policies. However, it is noted that the performance of Q-learning may
vary depending on the stability of future market conditions. Future work is
suggested, including experiments with updated Q-learning policies during
testing and trading diverse individual stocks. Additionally, the exploration of
alternative economic indicators for training the models is proposed.
| [
"q-fin.TR",
"cs.LG"
] | q-fin.TR | cs.LG | Trading and Market Microstructure;Machine Learning | 7,259Trading and Market Microstructure;Machine Learning
|
hep-lat/0310018 | We propose a new method for simulating QCD at finite density, where
interesting phases such as the color superconductivity phase is conjectured to
appear. The method is based on a general factorization property of distribution
functions of observables, and it is therefore applicable to any system with a
complex action. The so-called overlap problem is completely eliminated by the
use of constrained simulations. We test this method in a Random Matrix Theory
for finite density QCD, where we are able to reproduce the exact results for
the quark number density. The achieved system size is large enough to extract
the thermodynamic limit. Our results provide a clear understanding of how the
expected first order phase transition is induced by the imaginary part of the
action. We also discuss the noncommutativity of the zero chemical potential
limit and the thermodynamic limit, which is relevant to recent Monte Carlo
studies at small chemical potential.
| [
"hep-lat"
] | hep-lat | High Energy Physics - Lattice | 3,092High Energy Physics - Lattice
|
|
1204.3914 | We explore the magnetic properties of the Fermi-like liquid represented by
the D3-D7' system. The system exhibits interesting magnetic properties such as
ferromagnetism and an anomalous Hall effect, which are due to the Chern-Simons
term in the effective gravitational action. We investigate the spectrum of
quasi-normal modes in the presence of a magnetic field and show that the
magnetic field mitigates the instability towards a striped phase. In addition,
we find a critical magnetic field above which the zero sound mode becomes
massive.
| [
"hep-th",
"cond-mat.str-el"
] | hep-th | cond-mat.str-el | High Energy Physics - Theory;Strongly Correlated Electrons | 3,408High Energy Physics - Theory;Strongly Correlated Electrons
|
1506.06429 | We present the results of a very deep (500 ks) Chandra observation, along
with tailored numerical simulations, of the nearest, best resolved cluster cold
front in the sky, which lies 90 kpc (19 arcmin) to the north-west of M 87. The
northern part of the front appears the sharpest, with a width smaller than 2.5
kpc (1.5 Coulomb mean free paths; at 99 per cent confidence). Everywhere along
the front, the temperature discontinuity is narrower than 4-8 kpc and the
metallicity gradient is narrower than 6 kpc, indicating that diffusion,
conduction and mixing are suppressed across the interface. Such transport
processes can be naturally suppressed by magnetic fields aligned with the cold
front. Interestingly, comparison to magnetohydrodynamic simulations indicates
that in order to maintain the observed sharp density and temperature
discontinuities, conduction must also be suppressed along the magnetic field
lines. However, the northwestern part of the cold front is observed to have a
non-zero width. While other explanations are possible, the broadening is
consistent with the presence of Kelvin-Helmholtz instabilities (KHI) on
length-scales of a few kpc. Based on comparison with simulations, the presence
of KHI would imply that the effective viscosity of the intracluster medium is
suppressed by more than an order of magnitude with respect to the isotropic
Spitzer-like temperature dependent viscosity. Underneath the cold front, we
observe quasi-linear features that are ~10 per cent brighter than the
surrounding gas and are separated by ~15 kpc from each other in projection.
Comparison to tailored numerical simulations suggests that the observed
phenomena may be due to the amplification of magnetic fields by gas sloshing in
wide layers below the cold front, where the magnetic pressure reaches ~5-10 per
cent of the thermal pressure, reducing the gas density between the bright
features.
| [
"astro-ph.CO",
"astro-ph.GA",
"astro-ph.HE"
] | astro-ph.CO | astro-ph.GA | Cosmology and Nongalactic Astrophysics;Astrophysics of Galaxies;High Energy Astrophysical Phenomena | 1,732Cosmology and Nongalactic Astrophysics;Astrophysics of Galaxies;High Energy Astrophysical Phenomena
|
1109.2752 | Boolean optimization finds a wide range of application domains, that
motivated a number of different organizations of Boolean optimizers since the
mid 90s. Some of the most successful approaches are based on iterative calls to
an NP oracle, using either linear search, binary search or the identification
of unsatisfiable sub-formulas. The increasing use of Boolean optimizers in
practical settings raises the question of confidence in computed results. For
example, the issue of confidence is paramount in safety critical settings. One
way of increasing the confidence of the results computed by Boolean optimizers
is to develop techniques for validating the results. Recent work studied the
validation of Boolean optimizers based on branch-and-bound search. This paper
complements existing work, and develops methods for validating Boolean
optimizers that are based on iterative calls to an NP oracle. This entails
implementing solutions for validating both satisfiable and unsatisfiable
answers from the NP oracle. The work described in this paper can be applied to
a wide range of Boolean optimizers, that find application in Pseudo-Boolean
Optimization and in Maximum Satisfiability. Preliminary experimental results
indicate that the impact of the proposed method in overall performance is
negligible.
| [
"cs.AI"
] | cs.AI | Artificial Intelligence | 361Artificial Intelligence
|
|
1408.3948 | In this paper, we analyze finite difference schemes for Benjamin-Ono
equation, u_t = uu_x + Hu_{xx}, where H denotes the Hilbert transform. Both the
decaying case on the full line and the periodic case are considered. If the
initial data are sufficiently regular, fully discrete finite difference schemes
shown to converge to a classical solution. Finally, the convergence is
illustrated by several examples.
| [
"math.AP",
"math.NA"
] | math.AP | math.NA | Analysis of PDEs;Numerical Analysis | 253Analysis of PDEs;Numerical Analysis
|
1507.04915 | We prove that the continuous cohomology of $\text{Isom}^+(\mathbb{H}^n)$ can
be measurably realized on the boundary of hyperbolic space. This implies in
particular that for $\text{Isom}^+(\mathbb{H}^n)$ the comparison map from
continuous bounded cohomology to continuous cohomology is injective in degree
$3$. We furthermore prove a stability result for the continuous bounded
cohomology of $\text{Isom}(\mathbb{H}^n)$ and
$\text{Isom}(\mathbb{H}_{\mathbb{C}}^n)$.
| [
"math.GR",
"math.AT"
] | math.GR | math.AT | Group Theory;Algebraic Topology | 2,917Group Theory;Algebraic Topology
|
hep-th/0605097 | We re-interpret the anomaly cancellation conditions for the gauge symmetries
and the baryonic flavor symmetries in quiver gauge theories realized by the
brane tilings from the viewpoint of flux conservation on branes.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2010.14982 | Designing activity detection systems that can be successfully deployed in
daily-living environments requires datasets that pose the challenges typical of
real-world scenarios. In this paper, we introduce a new untrimmed daily-living
dataset that features several real-world challenges: Toyota Smarthome Untrimmed
(TSU). TSU contains a wide variety of activities performed in a spontaneous
manner. The dataset contains dense annotations including elementary, composite
activities and activities involving interactions with objects. We provide an
analysis of the real-world challenges featured by our dataset, highlighting the
open issues for detection algorithms. We show that current state-of-the-art
methods fail to achieve satisfactory performance on the TSU dataset. Therefore,
we propose a new baseline method for activity detection to tackle the novel
challenges provided by our dataset. This method leverages one modality (i.e.
optic flow) to generate the attention weights to guide another modality (i.e
RGB) to better detect the activity boundaries. This is particularly beneficial
to detect activities characterized by high temporal variance. We show that the
method we propose outperforms state-of-the-art methods on TSU and on another
popular challenging dataset, Charades.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
hep-ph/0002021 | We study the mixing of elementary and composite particles. In quantum field
theory the mixing of composite particles originates in the couplings of the
constituent quarks and for neutrinos in self-energy diagrams. In the event that
the incoming and outgoing neutrinos have different masses, the self-energy
diagrams vanish because energy is not conserved but the finite decaying widths
make the mixing possible. We can consider the neutrinos to be "fuzzy" states on
their mass shell and the mixing is understood as the overlap of two
wavefunctions. These considerations restrict the mass difference to be
approximately equal to or smaller than the largest of the two widths: abs(M_i -
M_j) lessorequal max(Gamma_i, Gamma_j).
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2110.13795 | We present a scalable star-shaped quantum key distribution (QKD) optical
fiber network. We use wavelength-division demultiplexing (WDM) of broadband
photon pairs to establish key exchange between multiple pairs of participants
simultaneously. Our QKD system is the first entanglement-based network of four
participants using BBM92 time-bin coding and the first network achieving timing
synchronization solely by clock recovery based on the photon arrival times. We
demonstrate simultaneous bipartite key exchange between any possible
combination of participants and show that the quantum bit error rate (QBER)
itself can be used to stabilize the phase in the interferometers by small
temperature adjustments. The key distribution is insensitive to polarization
fluctuations in the network, enabling key distribution using deployed fibers
even under challenging environmental conditions. We show that our network can
be readily extended to 34 participants by using a standard arrayed-waveguide
grating for WDM with 100 GHz channel spacing and that reconfigurable network
connections are possible with a wavelength-selective switch. In a field test we
demonstrate secure key rates of 6.3 bit/s with a QBER of 4.5% over a total
fiber length of 108 km with 26.8 km of deployed fiber between two participants
with high stability.
Our system features a relatively simple design of the receiver modules and
enables scaling QKD networks without a trusted nodes to distances up to more
than 100 km and to more than 100 users. With such a network, a secure
communication infrastructure on a metropolitan scale can be established.
| [
"quant-ph",
"physics.optics"
] | quant-ph | physics.optics | Quantum Physics;Optics | 6,146Quantum Physics;Optics
|
1908.09491 | Normalized exponential sums are entire functions of the form
$$
f(z)=1+H_1e^{w_1z}+\cdots+H_ne^{w_nz},
$$ where $H_1,\ldots, H_n\in\C$ and $0<w_1<\ldots<w_n$. It is known that the
zeros of such functions are in finitely many vertical strips $S$. The
asymptotic number of the zeros in the union of all these strips was found by R.
E. Langer already in 1931. In 1973, C. J. Moreno proved that there are zeros
arbitrarily close to any vertical line in any strip $S$, provided that
$1,w_1,\ldots,w_n$ are linearly independent over the rational numbers. In this
study the asymptotic number of zeros in each individual vertical strip is found
by relying on R. J. Backlund's lemma, which was originally used to study the
zeros of the Riemann $\zeta$-function. As a counterpart to Moreno's result, it
is shown that almost every vertical line meets at most finitely many small
discs around the zeros of $f$.
| [
"math.CV",
"math.NT"
] | math.CV | math.NT | Complex Variables;Number Theory | 1,158Complex Variables;Number Theory
|