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1104.3887 | AGN, such as blazars, are most often observed during flare states, primarily
due to ease of detection. We report microvariability observations of one
blazar, however, while in a historically low state. Comparisons of the
amplitude of the variability between high and low states are made. These
observations strongly suggest that the relativistic jet associated with the
central source of this object is responsible for the observed microvariability
(as opposed to a source within the accretion disk).
| [
"astro-ph.CO"
] | astro-ph.CO | Cosmology and Nongalactic Astrophysics | 1,725Cosmology and Nongalactic Astrophysics
|
|
2205.03414 | The remarkably high energies of the Large Hadron Collider (LHC) have allowed
for the first measurements of the shapes and scalings of multi-point
correlators of energy flow operators, $\langle \Psi | \mathcal{E}(\vec n_1)
\mathcal{E}(\vec n_2) \cdots \mathcal{E}(\vec n_k) |\Psi \rangle$, providing
new insights into the Lorentzian dynamics of quantum chromodynamics (QCD). In
this Letter, we use recent advances in effective field theory to derive a
rigorous factorization theorem for the light-ray density matrix, $\rho=
|\Psi\rangle \langle \Psi |$, inside high transverse momentum jets at the LHC.
Using the light-ray operator product expansion, the scaling behavior of
multi-point correlators can be computed from the expectation value of the
twist-2 spin-$J$ light-ray operators, $\mathbb{O}^{[J]}$, in this state,
$\text{Tr}[ \rho ~\mathbb{O}^{[J]} ]$. We compute the light-ray density matrix
at next-to-leading order, and combine this with results for the next-to-leading
logarithmic scaling behavior of the correlators up to six-points, comparing
with CMS Open Data. This theoretical accuracy allows us to resolve the quantum
scaling dimensions of QCD light-ray operators inside jets at the LHC. Our
factorization theorem for the light-ray density matrix at the LHC completes the
link between recent developments in the study of energy correlators and LHC
phenomenology, opening the door to a wide variety of precision jet substructure
studies.
| [
"hep-ph",
"hep-ex",
"nucl-ex",
"nucl-th"
] | hep-ph | hep-ex | High Energy Physics - Phenomenology;High Energy Physics - Experiment;Nuclear Experiment;Nuclear Theory | 3,215High Energy Physics - Phenomenology;High Energy Physics - Experiment;Nuclear Experiment;Nuclear Theory
|
physics/0407047 | This is a brief account of our numerical study of the tearing mode
reconnection. We demonstrate two main points. First, we show that, given
sufficiently small resistivity, the Rutherford regime always exists; larger
values of Delta' require smaller values of resistivity. Rutherford's
negligible-inertia assumption is validated and the asymptotically linear
dependence of the time derivative of the island width on the resistivity and
Delta' is confirmed. Second, we find that, at large Delta', the Rutherford
regime is followed by a nonlinear stage of fast growth linked to X-point
collapse and formation of a current sheet. This causes the reconnection to
become Sweet-Parke (SP) like. The signature resistivity^{1/2} scaling of the
effective island growth rate is, indeed, found in this nonlinear stage. The SP
stage culminates in the saturation of the mode, which can, thus, be achieved
much faster than via Rutherford regime.
| [
"physics.plasm-ph",
"physics.space-ph"
] | physics.plasm-ph | physics.space-ph | Plasma Physics;Space Physics | 5,606Plasma Physics;Space Physics
|
0809.2612 | The ESSENCE project was a six year supernova search carried out with the CTIO
4-m telescope. We also obtained spectra with many of the world's largest
ground-based telescopes and observed some of our SNe with the Hubble Space
Telescope and the Spitzer Space Telescope. We achieved our goal of discovering
over 200 Type Ia SNe in the redshift range 0.2 to 0.8. With these data we
determined the cosmic equation of state parameter to +/- 10 percent. The data
are consistent with a geometrically flat universe whose dark energy is
equivalent to Einstein's cosmological constant.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2304.06124 | ChatGPT has been emerging as a novel information source, and it is likely
that the public might seek information from ChatGPT while taking protective
actions when facing climate hazards such as floods and hurricanes. The
objective of this study is to evaluate the accuracy and completeness of
responses generated by ChatGPT when individuals seek information about aspects
of taking protective actions. The survey analysis results indicated that: (1)
the emergency managers considered the responses provided by ChatGPT as accurate
and complete to a great extent; (2) it was statistically verified in
evaluations that the generated information was accurate, but lacked
completeness, implying that the extent of information provided is accurate; and
(3) information generated for prompts related to hazard insurance received the
highest evaluation, whereas the information generated related to evacuation
received the lowest. This last result implies that, for complex,
context-specific protective actions (such as evacuation), the information was
rated as less complete compared with other protective actions. Also, the
results showed that the perception of respondents regarding the utility of AI-
assistive technologies (such as ChatGPT) for emergency preparedness and
response improved after taking the survey and evaluating the information
generated by ChatGPT. The findings from this study provide empirical evaluation
regarding the utility of AI-assistive technologies for improving public
decision-making and protective actions in disasters.
| [
"cs.CY"
] | cs.CY | Computers and Society | 1,646Computers and Society
|
|
2401.04443 | In this article, we described 1/2-derivations of solvable Lie algebras with a
thread-like nilradical. Nontrivial transposed Poisson algebras with solvable
Lie algebras are constructed. That is, by using 1/2-derivations of Lie
algebras, we have established commutative associative multiplication to
construct a transposed Poisson algebra with an associated given Lie algebra.
| [
"math.RA"
] | math.RA | Rings and Algebras | 6,272Rings and Algebras
|
|
1804.04402 | Interactive program verification is characterized by iterations of unfinished
proof attempts. To support the process of constructing a complete proof, many
interactive program verification systems offer a proof scripting language as a
text-based way to describe the non-automatic steps in a proof. Such scripting
languages are beneficial, but users spent a lot of effort on inspecting proof
scripts and the proofs they construct to detect the cause when a proof attempt
is unsuccessful and leads to unintended proof states. We present an offline and
replay debugger to support the user in analyzing proof attempts performed with
proof scripts. This debugger adapts successful concepts from software debugging
to the area of proof script debugging. The tool is built on top of KeY, a
system for deductive verification of Java programs. The debugger and its
graphical user interface are designed to support program verification in
particular, the underlying concepts and the implementation, however, are
adaptable to other provers and proof tasks.
| [
"cs.LO"
] | cs.LO | Logic in Computer Science | 3,801Logic in Computer Science
|
|
1010.2570 | A mean-field potential version of the Ultra-relativistic Quantum Molecular
Dynamics (UrQMD) model is used to investigate the production of strange
baryons, especially the $\Lambda$s and $\overline{\Lambda}$s, from heavy ion
collisions at SPS energies. It is found that, with the consideration of both
formed and pre-formed hadron potentials in UrQMD, the transverse mass and
longitudinal rapidity distributions of experimental data of both $\Lambda$s and
$\overline{\Lambda}$s can be quantitatively explained fairly well. Our
investigation also shows that both the production mechanism and the
rescattering process of hadrons play important roles in the final yield of
strange baryons.
| [
"nucl-th",
"hep-ex",
"hep-ph"
] | nucl-th | hep-ex | Nuclear Theory;High Energy Physics - Experiment;High Energy Physics - Phenomenology | 4,907Nuclear Theory;High Energy Physics - Experiment;High Energy Physics - Phenomenology
|
2105.00799 | In a recent Letter, it was suggested that a previously neglected Standard
Model process, namely, the production of antihelium-3 nuclei through decays of
$\bar\Lambda_b$ baryons can lead to a flux of antihelium-3 from dark matter
annihilations detectable by AMS-02. We show that an essential condition for its
detectability -- the introduction of the "$\bar\Lambda_b$ tune" of Pythia -- is
excluded by a wealth of measurements of (anti-) baryon and (anti-) meson
production at accelerators. Moreover, we argue that Monte Carlo generators like
Pythia should not be used to predict branching ratios like $BR(\bar\Lambda_b\to
\bar u d u (ud_0))$, which control the formation rate of antihelium-3. In
particular, we show that $\bar\Lambda_b$ decays which proceed via diquark
formation are overestimated by Pythia using its standard settings, which are
further enhanced in the "$\bar\Lambda_b$ tune".
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
0809.0973 | We use the combined GALFORM semi-analytical model of galaxy formation and
GRASIL spectrophotometric code to investigate the properties of galaxies
selected via their sub-mm emission. Our fiducial model has previously been
shown to fit the properties of local ULIRGs, as well as the number counts of
faint sub-mm galaxies. Here, we test the model in detail by comparing the SEDs
and stellar, dynamical, gas and halo masses of sub-mm galaxies against
observational data. We precisely mimic the sub-mm and radio selection function
of the observations and show that the predicted far-infrared properties of
model galaxies with S_850>5mJy and S_1.4>30uJy are in good agreement with
observations. Although the dust emission model does not assume a single dust
temperature, the far-infrared SEDs are well described by single component
modified black-body spectrum with characteristic temperature 32+/-5K. We also
find evidence that the observations may have uncovered evolution in the
far-infrared--radio relation in ULIRGs out to z~2. We show that the predicted
redshift distribution of sub-mm galaxies provides a reasonable fit to the
observational data with a median redshift z=2.0, with the radio-selected subset
predicted to make up approximately 75% of the population. However, the
predicted K-band and mid-infrared (3--8um) flux densities of the sub-mm
galaxies (and LBGs) are up to a factor 10x fainter than observed. This
discrepancy may indicate that the stellar masses of the sub-mm galaxies in the
model are too low: M~10^10Mo, while observations suggest more massive systems,
M~10^11Mo. Finally, we discuss the potential modifications to the models which
may improve the fit to the observational data. [Abridged]
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
1805.07772 | Energy-time uncertainty plays an important role in quantum foundations and
technologies, and it was even discussed by the founders of quantum mechanics.
However, standard approaches (e.g., Robertson's uncertainty relation) do not
apply to energy-time uncertainty because, in general, there is no Hermitian
operator associated with time. Following previous approaches, we quantify time
uncertainty by how well one can read off the time from a quantum clock. We then
use entropy to quantify the information-theoretic distinguishability of the
various time states of the clock. Our main result is an entropic energy-time
uncertainty relation for general time-independent Hamiltonians, stated for both
the discrete-time and continuous-time cases. Our uncertainty relation is
strong, in the sense that it allows for a quantum memory to help reduce the
uncertainty, and this formulation leads us to reinterpret it as a bound on the
relative entropy of asymmetry. Due to the operational relevance of entropy, we
anticipate that our uncertainty relation will have information-processing
applications.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
math/0512644 | The Hausdorff dimension of an exceptional set of periods for which
convergence of a formal solution to an inhomogeneous wave equation in n spatial
and one temporal dimension is problematic, is determined along with conditions
which the periods must satisfy to ensure the solvability of the inhomogeneous
wave equation by a smooth periodic function. To derive this information, a
complete metric theory for a related fully nonlinear Diophantine approximation
problem involving perfect squares is established.
| [
"math.AP",
"math.NT"
] | math.AP | math.NT | Analysis of PDEs;Number Theory | 252Analysis of PDEs;Number Theory
|
1810.07125 | The CoNLL--SIGMORPHON 2018 shared task on supervised learning of
morphological generation featured data sets from 103 typologically diverse
languages. Apart from extending the number of languages involved in earlier
supervised tasks of generating inflected forms, this year the shared task also
featured a new second task which asked participants to inflect words in
sentential context, similar to a cloze task. This second task featured seven
languages. Task 1 received 27 submissions and task 2 received 6 submissions.
Both tasks featured a low, medium, and high data condition. Nearly all
submissions featured a neural component and built on highly-ranked systems from
the earlier 2017 shared task. In the inflection task (task 1), 41 of the 52
languages present in last year's inflection task showed improvement by the best
systems in the low-resource setting. The cloze task (task 2) proved to be
difficult, and few submissions managed to consistently improve upon both a
simple neural baseline system and a lemma-repeating baseline.
| [
"cs.CL"
] | cs.CL | Computation and Language | 1,168Computation and Language
|
|
2212.09523 | Artificial intelligence and natural language processing (NLP) are
increasingly being used in customer service to interact with users and answer
their questions. The goal of this systematic review is to examine existing
research on the use of NLP technology in customer service, including the
research domain, applications, datasets used, and evaluation methods. The
review also looks at the future direction of the field and any significant
limitations. The review covers the time period from 2015 to 2022 and includes
papers from five major scientific databases. Chatbots and question-answering
systems were found to be used in 10 main fields, with the most common use in
general, social networking, and e-commerce areas. Twitter was the second most
commonly used dataset, with most research also using their own original
datasets. Accuracy, precision, recall, and F1 were the most common evaluation
methods. Future work aims to improve the performance and understanding of user
behavior and emotions, and address limitations such as the volume, diversity,
and quality of datasets. This review includes research on different spoken
languages and models and techniques.
| [
"cs.CL",
"cs.AI"
] | cs.CL | cs.AI | Computation and Language;Artificial Intelligence | 1,170Computation and Language;Artificial Intelligence
|
1608.08328 | We apply a recently developed method (V. A. Dzuba, PRA 90, 012517 (2014); J.
S. M. Ginges and V. A. Dzuba, PRA 91, 042505 (2015)) to calculate energy levels
of superheavy elements Uut (Z = 113), Fl (Z = 114), and Fl+. The method
combines the linearized single-double coupledcluster technigue, the all-order
correlation potential method and configuration interaction method. Breit and
quantum electrodynamic corrections are included. The role of relativistic and
correlation effects is discussed. Similar calculations for Tl, Pb and Pb+ are
used to gauge the accuracy of the calculations.
| [
"physics.atom-ph"
] | physics.atom-ph | Atomic Physics | 569Atomic Physics
|
|
hep-ex/9910024 | The diffractive dissociation of 500 GeV/c $\pi^-$ into di-jets is described
as a way to measure the momentum distribution of quarks in the pion. The
measurements of the pion diffractive dissociation were carried out using data
from Fermilab E791. Preliminary results show that the $|q\bar {q}>$ Asymptotic
wave function which was developed using perturbative QCD methods describes the
data well for $Q^2 \sim 10 ~{\rm (GeV/c)^2}$. At these values signals of color
transparency are expected and, indeed, observed through the $A$-dependence of
the yield of the diffractive di-jets.
| [
"hep-ex"
] | hep-ex | High Energy Physics - Experiment | 3,059High Energy Physics - Experiment
|
|
cond-mat/0208599 | Motivated by experiments on wormlike micelles, we study the early stages of
the shear banding instability using a two-fluid Johnson-Segalman model. We
perform a linear stability analysis for coupled fluctuations in shear rate,
micellar strain and concentration about an initially homogeneous state. First
we calculate the ``spinodal'' onset of instability in sweeps along the
intrinsic constitutive curve. For startup ``quenches'' into the unstable
region, the instability usually occurs before the intrinsic constitutive curve
can be attained so we analyse the fluctuations with respect to the homogeneous
startup flow to find the selected length and time scales at which inhomogeneity
first emerges. In the uncoupled limit, fluctuations in shear rate and micellar
strain are independent of those in concentration, and are unstable when the
intrinsic constitutive curve has negative slope; but no length scale is
selected. When coupled to concentration, this instability is enhanced at short
length scales; a length scale is selected, as seen experimentally. The unstable
region is then broadened. Far from an underlying (zero-shear) demixing
instability, the broadening is slight and the instability is still dominated by
shear rate and micellar strain. Close to demixing, instability sets in at very
low shear rate, where it is demixing triggered by flow.
| [
"cond-mat.soft",
"cond-mat.stat-mech"
] | cond-mat.soft | cond-mat.stat-mech | Soft Condensed Matter;Statistical Mechanics | 6,608Soft Condensed Matter;Statistical Mechanics
|
2105.00840 | In this paper, we investigate the invasion percolation (IP) in imperfect
support in which the configuration of imperfections is considered to be
correlated. Three lattice models were engaged to realize this pattern: site
percolation, Ising model and random Coulomb potential (RCP). The first two
models are short range interaction (SRI), whereas the last one includes coulomb
like interactions which is pretty long range (long-range interactions, LRI). By
examining various dynamical observables we show that the critical exponents of
SRI IP are robust against the control parameters (temperature in the Ising
model and occupation probability in site percolation), whereas its properties
in the LRI (RCP) supports are completely different from the normal IP (i.e. on
the regular lattice). Especially the fractal dimension of the external frontier
of the largest hole converges to $1.099\pm 0.008$ for RCP IP, whereas it is
nearly $\frac{4}{3}$ for SRI IP being compatible with normal IP. Additionally a
novel dynamical crossover is seen in the RCP IP according to which the time
dependence of all of the observables is divided to three parts: the power-law
(small times), the logarithmic (mid time), and the linear (long time) regimes.
The second crossover time is shown to go to infinity in the thermodynamic
limit, whereas the first crossover time is nearly unchanged, signaling the
dominance of the logarithmic regime. The observables become nearly constant in
the thermodynamic limit for the long time, showing that it is a stationary
phase.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
2105.06157 | Carpet-type structures constitute an ideal laboratory to study and analyze
the robustness of the interference process that underlies this phenomenon
against the harmful effects of decoherence. Here, without losing any
generality, for simplicity, the case of a particle with a mass m is considered
and described by a localized state corresponding to the ground state of a
square box of width w, which is released inside a wider cavity (with a width L
> w). The effects of decoherence are then numerically investigated by means of
a simple dynamical model that captures the essential features of the phenomenon
under Markovian conditions, leaving aside extra complications associated with a
more detailed dynamical description of the system-environment interaction. As
it is shown, this model takes into account and reproduces the fact that
decoherence effects are stronger as energy levels become more separated (in
energy), which translates into a progressive collapse of the energy density
matrix to its main diagonal. However, because energy dissipation is not
considered, an analogous behavior is not observed in the position
representation, where a proper spatial localization of the probability density
does not take place, but rather a delocalized distribution. This result
emphasizes the fact that classicality is reached only if both decoherence and
dissipation coexist; otherwise, non-classical traits might still persist.
Actually, as it is also shown, in the position representation some off-diagonal
correlations indeed survive unless an additional spatial-type factor is
included in the model. This makes evident the rather complex nature of the
decoherence phenomenon and hence the importance to have a familiarity with how
it manifests in different representations, particularly with the purpose to
determine and design reliable control mechanisms.
| [
"quant-ph",
"physics.optics"
] | quant-ph | physics.optics | Quantum Physics;Optics | 6,146Quantum Physics;Optics
|
1810.07964 | A rigid set in a curve complex of a surface is a subcomplex such that every
locally injective simplicial map from the set into the curve complex is induced
by a homeomorphism of the surface. In this paper, we find finite rigid sets in
the curve complexes of connected non-orientable surfaces of genus $g$ with $n$
holes for $g+n \neq 4$.
| [
"math.GT"
] | math.GT | Geometric Topology | 2,813Geometric Topology
|
|
0904.2523 | We have performed small-angle neutron scattering (SANS) of the flux line
lattice (FLL) in a Fe doped NbSe_2 sample which presents a large peak effect in
the critical current. The scattered intensity and the width of the Bragg peaks
of the equilibrium FLL indicate an ordered structure in the peak effect zone.
The history dependence in the FLL structure has been studied using field cooled
and zero field cooled procedures, and each state shows the same intensity of
Bragg scattering and good orientational order. These results strongly suggest
that the peak effect is unrelated to a bulk disordering transition, and confirm
the role of a heterogeneous distribution of screening current.
| [
"cond-mat.supr-con"
] | cond-mat.supr-con | Superconductivity | 7,066Superconductivity
|
|
2006.15965 | This paper contributes to the classification of positive scalar curvature
metrics up to bordism and up to concordance. Let $M$ be a closed spin manifold
of dimension $\ge 5$ which admits a metric with positive scalar curvature. We
give lower bounds on the rank of the group of psc metrics over $M$ up to
bordism in terms of the corank of the canonical map $KO_*(M)\to
KO_*(B\pi_1(M))$, provided the rational analytic Novikov conjecture is true for
$\pi_1(M)$.
| [
"math.KT",
"math.DG",
"math.GT"
] | math.KT | math.DG | K-Theory and Homology;Differential Geometry;Geometric Topology | 7,267longtail
|
1310.6098 | In this paper, we are concerned with a shape design problem, in which our
target is to design, up to rigid transformations and scaling, the shape of an
object given either its polarization tensor at multiple contrasts or the
partial eigenvalues of its Neumann-Poincar\'e operator, which are known as the
Fredholm eigenvalues. We begin by proposing to recover the eigenvalues of the
Neumann-Poincar\'e operator from the polarization tensor by means of the
holomorphic functional calculus. Then we develop a regularized Gauss-Newton
optimization method for the shape reconstruction process. We present numerical
results to demonstrate the effectiveness of the proposed methods and to
illustrate important properties of the Fredholm eigenvalues and their
associated eigenfunctions. Our results are expected to have important
applications in the design of plasmon resonances in nanoparticles as well as in
the multifrequency or pulsed imaging of small anomalies.
| [
"math.OC",
"math.NA"
] | math.OC | math.NA | Optimization and Control;Numerical Analysis | 5,318Optimization and Control;Numerical Analysis
|
2102.06300 | Magnetic wave perturbations are observed in the solar wind and in the
vicinity of Earth's bow shock. For such environments, recent work on magnetic
pumping with electrons trapped in the magnetic perturbations have demonstrated
the possibility of efficient energization of superthermal electrons. Here we
also analyze the energization of such energetic electrons for which the transit
time through the system is short compared to time scales associated with the
magnetic field evolution. In particular, considering an idealized magnetic
configuration we show how trapping/detrapping of energetic magnetized electrons
can cause effective parallel velocity diffusion. This parallel diffusion,
combined with naturally occurring mechanisms known to cause pitch angle
scattering, such as Whistler waves, produces enhanced heating rates for
magnetic pumping. We find that at low pitch angle scattering rates the combined
mechanism enhances the heating beyond the predictions of the recent theory for
magnetic pumping with trapped electrons.
| [
"physics.plasm-ph",
"physics.space-ph"
] | physics.plasm-ph | physics.space-ph | Plasma Physics;Space Physics | 5,606Plasma Physics;Space Physics
|
1402.5027 | We construct a duality manifest gravitational theory for the special linear
group, ${\mathbf{SL}(N)}$ with $N{\neq 4}$. The spacetime is formally extended,
to have the dimension $\textstyle{\frac{1}{2}} N(N-1)$, yet is `gauged'.
Consequently the theory is subject to a section condition. We introduce a
semi-covariant derivative and a semi-covariant `Riemann' curvature, both of
which can be completely covariantized after symmetrizing or contracting the
${\mathbf{SL}(N)}$ vector indices properly. Fully covariant scalar and `Ricci'
curvatures then constitute the action and the `Einstein' equation of motion.
For $N\geq 5$, the section condition admits duality inequivalent two solutions,
one $(N-1)$-dimensional and the other three-dimensional. In each case, the
theory can describe not only Riemannian but also non-Riemannian backgrounds.
| [
"hep-th",
"math.DG"
] | hep-th | math.DG | High Energy Physics - Theory;Differential Geometry | 3,312High Energy Physics - Theory;Differential Geometry
|
1402.0938 | We settle a question posed by Umehara and Yamada, which generalizes a
completeness lemma useful in differential geometry.
| [
"math.DG"
] | math.DG | Differential Geometry | 2,010Differential Geometry
|
|
1507.01572 | We complement the analysis of the anomalous top-Higgs coupling effects on the
secondary lepton distributions in the associated production of the top-quark
pair and Higgs boson in proton-proton collisions at the LHC of the former work
by one of the present authors by taking into account the quark-antiquark
production mechanism. We also present simple arguments which explain why the
effects of the scalar and pseudoscalar anomalous couplings on the unpolarized
cross section of the process are completely insensitive to the sign of either
of them.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
nlin/0403016 | The Dirac method of quantizing Hamiltonian systems with constraints is
applied to the massless Thirring model. We solve the quantum Hamiltonian
equation for the energy-momentum tensor and obtain a violation of the classical
conservation law.A previously noticed problem with the equal-time
anticommutators can be fixed using this Hamiltonian method.
| [
"nlin.SI"
] | nlin.SI | Exactly Solvable and Integrable Systems | 2,430Exactly Solvable and Integrable Systems
|
|
2103.01940 | In this paper we consider systems of quantum particles in the $4d$ Euclidean
space which enjoy conformal symmetry. The algebraic relations for
conformal-invariant combinations of positions and momenta are used to construct
a solution of the Yang-Baxter equation in the unitary irreducibile
representations of the principal series $\Delta=2+i\nu$ for any left/right
spins $\ell,\dot{\ell}$ of the particles. Such relations are interpreted in the
language of Feynman diagrams as integral \emph{star-triangle} identites between
propagators of a conformal field theory. We prove the quantum integrability of
a spin chain whose $k$-th site hosts a particle in the representation
$(\Delta_k,\ell_k, \dot{ \ell}_k)$ of the conformal group, realizing a spinning
and inhomogeneous version of the quantum magnet used to describe the spectrum
of the bi-scalar Fishnet theories. For the special choice of particles in the
scalar $(1,0,0)$ and fermionic $(3/2,1,0)$ representation the transfer matrices
of the model are Bethe-Salpeter kernels for the double-scaling limit of
specific two-point correlators in the $\gamma$-deformed $\mathcal{N}=4$ and
$\mathcal{N}=2$ supersymmetric theories.
| [
"hep-th",
"nlin.SI"
] | hep-th | nlin.SI | High Energy Physics - Theory;Exactly Solvable and Integrable Systems | 3,317High Energy Physics - Theory;Exactly Solvable and Integrable Systems
|
0911.3454 | Various real-life networks of current interest are simultaneously scale-free
and modular. Here we study analytically the average distance in a class of
deterministically growing scale-free modular networks. By virtue of the
recursive relations derived from the self-similar structure of the networks, we
compute rigorously this important quantity, obtaining an explicit closed-form
solution, which recovers the previous result and is corroborated by extensive
numerical calculations. The obtained exact expression shows that the average
distance scales logarithmically with the number of nodes in the networks,
indicating an existence of small-world behavior. We present that this
small-world phenomenon comes from the peculiar architecture of the network
family.
| [
"physics.soc-ph",
"cond-mat.stat-mech"
] | physics.soc-ph | cond-mat.stat-mech | Physics and Society;Statistical Mechanics | 5,540Physics and Society;Statistical Mechanics
|
1712.01648 | The dynamics of agent-based systems provide a framework to face the
complexity of pedestrian-vehicle interactions in future cities, in which the
compliance to traffic norms plays a fundamental role. The data of an
observation performed at a non-signalized intersection are presented to provide
useful insights for supporting the future development of agent-based models.
Results focus on drivers' compliance to crossing pedestrians, describing
potentially conflictual interactions among heterogeneous agents. The discussion
closes with the potential applications of the collected data set for modelling
the phenomenon.
| [
"cs.MA"
] | cs.MA | Multiagent Systems | 4,667Multiagent Systems
|
|
2201.07576 | We study the non-trivial phase of the two-dimensional breathing kagome
lattice, displaying both edge and corner modes. The corner localized modes of a
two-dimensional flake were initially identified as a signature of a
higher-order topological phase but later shown to be trivial for perturbations
that were thought to protect them. Using various theoretical and simulation
techniques, we confirm that it does not display higher-order topology: the
corner modes are of trivial nature. Nevertheless, they might be protected.
First, we show a set of perturbations within a tight-binding model that can
move the corner modes away from zero energy, also repeat some perturbations
that were used to show that the modes are trivial. In addition, we analyze the
protection of the corner modes in more detail and find that only perturbations
respecting the sublattice or generalized chiral and crystalline symmetries, and
the lattice connectivity, pin the corner modes to zero energy robustly. A
destructive interference model corroborates the results. Finally, we analyze a
muffin-tin model for the bulk breathing kagome lattice. Using topological and
symmetry markers, such as Wilson loops and Topological Quantum Chemistry, we
identify the two breathing phases as adiabatically disconnected different
obstructed atomic limits.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
1506.01306 | The critical fluctuations at second order structural transitions in a bulk
crystal may affect the dissipation of mechanical probes even if completely
external to the crystal surface. Here we show that noncontact force microscope
dissipation bears clear evidence of the antiferrodistortive phase transition of
SrTiO3, known for a long time to exhibit a unique, extremely narrow neutron
scattering "central peak". The noncontact geometry suggests a central peak
linear response coupling connected with strain. The detailed temperature
dependence reveals for the first time the intrinsic central peak width of order
80 kHz, two orders of magnitude below the established neutron upper bound.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
2112.11720 | Given a graph $G$, a dominating set of $G$ is a set $S$ of vertices such that
each vertex not in $S$ has a neighbor in $S$. The domination number of $G$,
denoted $\gamma(G)$, is the minimum size of a dominating set of $G$. The
independent domination number of $G$, denoted $i(G)$, is the minimum size of a
dominating set of $G$ that is also independent.
Recently, Abrishami and Henning proved that if $G$ is a cubic graph with
girth at least $6$, then $i(G) \le \frac{4}{11}|V(G)|$. We show a result that
not only improves upon the upper bound of the aforementioned result, but also
applies to a larger class of graphs, and is also tight. Namely, we prove that
if $G$ is a cubic graph without $4$-cycles, then $i(G) \le \frac{5}{14}|V(G)|$,
which is tight. Our result also implies that every cubic graph $G$ without
$4$-cycles satisfies $\frac{i(G)}{\gamma(G)} \le \frac{5}{4}$, which partially
answers a question by O and West in the affirmative.
| [
"math.CO"
] | math.CO | Combinatorics | 1,014Combinatorics
|
|
2201.10860 | Physical field reconstruction is highly desirable for the measurement and
control of engineering systems. The reconstruction of the temperature field
from limited observation plays a crucial role in thermal management for
electronic equipment. Deep learning has been employed in physical field
reconstruction, whereas the accurate estimation for the regions with large
gradients is still diffcult. To solve the problem, this work proposes a novel
deep learning method based on patchwise training to reconstruct the temperature
field of electronic equipment accurately from limited observation. Firstly, the
temperature field reconstruction (TFR) problem of the electronic equipment is
modeled mathematically and transformed as an image-to-image regression task.
Then a patchwise training and inference framework consisting of an adaptive
UNet and a shallow multilayer perceptron (MLP) is developed to establish the
mapping from the observation to the temperature field. The adaptive UNet is
utilized to reconstruct the whole temperature field while the MLP is designed
to predict the patches with large temperature gradients. Experiments employing
finite element simulation data are conducted to demonstrate the accuracy of the
proposed method. Furthermore, the generalization is evaluated by investigating
cases under different heat source layouts, different power intensities, and
different observation point locations. The maximum absolute errors of the
reconstructed temperature field are less than 1K under the patchwise training
approach.
| [
"cs.LG",
"cs.AI"
] | cs.LG | cs.AI | Machine Learning;Artificial Intelligence | 3,892Machine Learning;Artificial Intelligence
|
hep-ph/9702213 | The analytic behavior of the heavy-light meson form factor is investigated
using several relativistic examples including unconfined, weakly confined, and
strongly confined mesons. It is observed that confinement erases the anomalous
threshold singularity and also induces an essential singularity at the normal
annihilation threshold. In the weak confinement limit, the "would be" anomalous
threshold contribution is identical to that of the real singularity on its
space-like side.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2206.09141 | Robots assisting us in environments such as factories or homes must learn to
make use of objects as tools to perform tasks, for instance using a tray to
carry objects. We consider the problem of learning commonsense knowledge of
when a tool may be useful and how its use may be composed with other tools to
accomplish a high-level task instructed by a human. Specifically, we introduce
a novel neural model, termed TOOLTANGO, that first predicts the next tool to be
used, and then uses this information to predict the next action. We show that
this joint model can inform learning of a fine-grained policy enabling the
robot to use a particular tool in sequence and adds a significant value in
making the model more accurate. TOOLTANGO encodes the world state, comprising
objects and symbolic relationships between them, using a graph neural network
and is trained using demonstrations from human teachers instructing a virtual
robot in a physics simulator. The model learns to attend over the scene using
knowledge of the goal and the action history, finally decoding the symbolic
action to execute. Crucially, we address generalization to unseen environments
where some known tools are missing, but alternative unseen tools are present.
We show that by augmenting the representation of the environment with
pre-trained embeddings derived from a knowledge-base, the model can generalize
effectively to novel environments. Experimental results show at least
48.8-58.1% absolute improvement over the baselines in predicting successful
symbolic plans for a simulated mobile manipulator in novel environments with
unseen objects. This work takes a step in the direction of enabling robots to
rapidly synthesize robust plans for complex tasks, particularly in novel
settings
| [
"cs.RO"
] | cs.RO | Robotics | 6,325Robotics
|
|
hep-ph/0210379 | We study the impact of recent B-factories measurements and upper limit of
radiative and semileptonic rare B-decays. We present model independent
constraints on the relevant Wilson coefficients and show the impact on the
parameter space of some concrete realizations of the Minimal Supersymmetric
Standard Model.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1202.4818 | In this paper a new mining algorithm is defined based on frequent item set.
Apriori Algorithm scans the database every time when it finds the frequent item
set so it is very time consuming and at each step it generates candidate item
set. So for large databases it takes lots of space to store candidate item set
.In undirected item set graph, it is improvement on apriori but it takes time
and space for tree generation. The defined algorithm scans the database at the
start only once and then from that scanned data base it generates the Trade
List. It contains the information of whole database. By considering minimum
support it finds the frequent item set and by considering the minimum
confidence it generates the association rule. If database and minimum support
is changed, the new algorithm finds the new frequent items by scanning Trade
List. That is why it's executing efficiency is improved distinctly compared to
traditional algorithm.
| [
"cs.DB"
] | cs.DB | Databases | 1,977Databases
|
|
astro-ph/0703088 | The dynamical evolution of nearly half of the known extrasolar planets in
multiple-planet systems may be dominated by secular perturbations. The commonly
high eccentricities of the planetary orbits calls into question the utility of
the traditional Laplace-Lagrange (LL) secular theory in analyses of the motion.
We analytically generalize this theory to fourth-order in the eccentricities,
compare the result with the second-order theory and octupole-level theory, and
apply these theories to the likely secularly-dominated HD 12661, HD 168443, HD
38529 and Ups And multi-planet systems. The fourth-order scheme yields a
multiply-branched criterion for maintaining apsidal libration, and implies that
the apsidal rate of a small body is a function of its initial eccentricity,
dependencies which are absent from the traditional theory. Numerical results
indicate that the primary difference the second and fourth-order theories
reveal is an alteration in secular periodicities, and to a smaller extent
amplitudes of the planetary eccentricity variation. Comparison with numerical
integrations indicates that the improvement afforded by the fourth-order theory
over the second-order theory sometimes dwarfs the improvement needed to
reproduce the actual dynamical evolution. We conclude that LL secular theory,
to any order, generally represents a poor barometer for predicting secular
dynamics in extrasolar planetary systems, but does embody a useful tool for
extracting an accurate long-term dynamical description of systems with small
bodies and/or near-circular orbits.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2307.01437 | Aerocapture is a technique which uses atmospheric drag to decelerate a
spacecraft and achieve nearly fuel-free orbit insertion from an interplanetary
trajectory. The present study performs a historical review of the field, and a
bibliometric data analysis of the literature from 1980 to 2023. The data offers
insights into the evolution of the field, current state of research, and
pathways for its continued development. The data reveal a pattern in the rise
of publications, followed by a period of stagnation, which repeats itself
approximately once every decade. Mars is the most studied destination, while
Uranus is the least studied. Prior to 2013, NASA centers produced the most
publications and are the most cited in the field. However, academic
institutions produced the majority of publications in the last decade. The
United States continues to be the leading country in terms of publications,
followed by China. The Journal of Spacecraft and Rockets is the leading source
of publications, both in terms of number and citations. NASA is the leading
funding source, followed by the National Natural Science Foundation of China. A
proposed low-cost Earth flight demonstration of aerocapture will greatly reduce
the risk for future science missions.
| [
"astro-ph.EP",
"astro-ph.IM",
"physics.app-ph"
] | astro-ph.EP | astro-ph.IM | Earth and Planetary Astrophysics;Instrumentation and Methods for Astrophysics;Applied Physics | 2,377Earth and Planetary Astrophysics;Instrumentation and Methods for Astrophysics;Applied Physics
|
2011.09791 | Since the inception of the atomic force microscope AFM, dynamic methods have
been very fruitful by establishing methods to quantify dissipative and
conservative forces in the nanoscale and by providing a means to apply gentle
forces to the samples with high resolution. Here we review developments that
cover over a decade of our work on energy dissipation, phase contrast and the
extraction of relevant material properties from observables. We describe the
attempts to recover material properties via one dimensional amplitude and phase
curves from force models and explore the evolution of these methods in terms of
force reconstruction, fits of experimental measurements, and the more recent
advances in multifrequency AFM.
| [
"cond-mat.mes-hall",
"cond-mat.mtrl-sci"
] | cond-mat.mes-hall | cond-mat.mtrl-sci | Mesoscale and Nanoscale Physics;Materials Science | 4,493Mesoscale and Nanoscale Physics;Materials Science
|
2112.06372 | Future wireless communications look forward to constructing a ubiquitous
intelligent information network with high data rates through cost-efficient
devices. Benefiting from the tunability and programmability of metamaterials,
the reconfigurable holographic surface (RHS) composed of numerous metamaterial
radiation elements is developed as a promising solution to fulfill such
challenging visions. The RHS is more likely to serve as an ultra-thin and
lightweight surface antenna integrated with the transceiver to generate beams
with desirable directions by leveraging the holographic principle. This is
different from reconfigurable intelligent surfaces (RISs) widely used as
passive relays due to the reflection characteristic. In this article, we
investigate RHS-aided wireless communications. Starting with a basic
introduction of the RHS including its hardware structure, holographic
principle, and fabrication methodologies, we propose a hybrid beamforming
scheme for RHS-aided multi-user communication systems. A joint sum-rate
maximization algorithm is then developed where the digital beamforming
performed at the base station and the holographic beamforming performed at the
RHS are optimized iteratively. Furthermore, key challenges in RHS-aided
wireless communications are also discussed.
| [
"eess.SP"
] | eess.SP | Signal Processing | 6,402Signal Processing
|
|
1312.0853 | A pinned or free-floating rigid plate lying on the free surface of a thin
film of viscous fluid, which itself lies on top of a horizontal substrate that
is moving to the right at a constant speed is considered. The focus of the
present work is to describe how the competing effects of the speed of the
substrate, surface tension, viscosity, and, in the case of a pinned plate, the
prescribed pressure in the reservoir of fluid at its upstream end, determine
the possible equilibrium positions of the plate, the free surface, and the flow
within the film. The present problems are of interest both in their own right
as paradigms for a range of fluid-structure interaction problems in which
viscosity and surface tension both play an important role, and as a first step
towards the study of elastic effects.
| [
"physics.class-ph",
"physics.flu-dyn"
] | physics.class-ph | physics.flu-dyn | Classical Physics;Fluid Dynamics | 992Classical Physics;Fluid Dynamics
|
2210.16562 | We report a structural reconstruction-induced high photoluminescence quantum
yield of 25% in colloidal two-dimensional tin iodide nanosheets that are
synthesized by a hot-injection method. The as-synthesized red-colored
nanosheets of octylammonium tin iodide perovskites at room temperature
transform to white hexagonal nanosheets upon washing or exposure to light. This
structural change increases the bandgap from 2.0 eV to 3.0 eV, inducing a large
Stokes shift and a broadband emission. Further, a long photoluminescence
lifetime of about 1 microsecond is measured for the nanosheets. Such long-lived
broad and intense photoluminescence with large Stokes shift is anticipated to
originate from tin iodide clusters that are formed during the structural
reconstruction. Stereoactive 5s2 lone pair of tin (II) ions perturbs the
excited state geometry of the white hexagonal nanosheets and facilitates the
formation of self-trapped excitons. Such broadband and intensely emitting metal
halide nanosheets are promising for white light-emitting diodes.
| [
"physics.app-ph",
"cond-mat.mtrl-sci"
] | physics.app-ph | cond-mat.mtrl-sci | Applied Physics;Materials Science | 333Applied Physics;Materials Science
|
cond-mat/0106159 | Using classical molecular dynamics simulations we examine the formation of
craters during 0.4 - 100 keV Xe bombardment of Au. Our simulation results, and
comparison with experiments and simulations of other groups, are used to
examine to what extent analytical models can be used to predict the size and
properties of craters. We do not obtain a fully predictive analytical model
(with no fitting parameters) for the cratering probability, because of the
difficulty in predicting the probability of cascades splitting into
subcascades, and the relation of the heat spike lifetime and energy density. We
do, however, demonstrate that the dependence of the crater size on the incident
ion energy can be well understood qualitatively in terms of the lifetime of the
heat spike and the cohesive energy of the material. We also show that a simple
energy density criterion can not be used to predict cratering in a wide ion
energy range because of the important role of the heat spike lifetime in
high-energy cascades. The cohesive energy dependence differs from that obtained
for macroscopic cratering (observed e.g. in astrophysics) because of the
crucial role of melting in the development of heat spikes.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
1706.02680 | Manual maintenance and repair of cracks in concrete structures are often
unsustainable because of associated labor, capital and environmental damage.
Introduction of microfibers and superabsorbent polymers is a material solution
to restrict crack propagation and enhance self-healing efficiency. Therefore,
the study proposes a combination of polypropylene(PP) fibers and superabsorbent
polymers (SAP) which would facilitate autonomous healing and recover original
mechanical and durability properties of mortar. Mechanical strength, sorptivity
and water penetration of healed mortars were compared to that of undamaged
mortar at same age to estimate recovery of original properties while crack
sealing was investigated by means of optical microscopy. Experimental results
show mortar with combination of PP fibers and SAP showed full recovery of
mechanical strength after healing while recovery in durability up to 90% was
recorded. Microscopic images show that average crack-sealing ratio of 85% could
be achieved under moist condition by combination of SAP and PP fibers while
sealing under drier air curing condition is also significantly higher than
reference samples with only fibers. Crack width up to 330{\mu}m has been found
to be completely sealed by carbonate crystals. Furthermore, mortar with SAP and
PP fibers retain about 70% of their original 28-day strength after three cycles
of loading while reference mortar samples were found to retain only about
40-50% of their original strength. Effective crack sealing and high recovery of
original properties in mortars with SAP and fibers suggest that this material
combination would reduce the need for environmentally damaging and expensive
repairs during the service life.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
2004.06774 | Time-critical analysis of social media streams is important for humanitarian
organizations for planing rapid response during disasters. The \textit{crisis
informatics} research community has developed several techniques and systems
for processing and classifying big crisis-related data posted on social media.
However, due to the dispersed nature of the datasets used in the literature
(e.g., for training models), it is not possible to compare the results and
measure the progress made towards building better models for crisis informatics
tasks. In this work, we attempt to bridge this gap by combining various
existing crisis-related datasets. We consolidate eight human-annotated datasets
and provide 166.1k and 141.5k tweets for \textit{informativeness} and
\textit{humanitarian} classification tasks, respectively. We believe that the
consolidated dataset will help train more sophisticated models. Moreover, we
provide benchmarks for both binary and multiclass classification tasks using
several deep learning architecrures including, CNN, fastText, and transformers.
We make the dataset and scripts available at:
https://crisisnlp.qcri.org/crisis_datasets_benchmarks.html
| [
"cs.SI",
"cs.AI",
"cs.CY",
"cs.IR"
] | cs.SI | cs.AI | Social and Information Networks;Artificial Intelligence;Computers and Society;Information Retrieval | 7,267longtail
|
1004.0199 | We point out a simple characterisation of topological amenability in terms of
bounded cohomology, following Johnson's reformulation of amenability.
| [
"math.GR"
] | math.GR | Group Theory | 2,913Group Theory
|
|
2212.12394 | A key challenge in building effective regression models for large and diverse
populations is accounting for patient heterogeneity. An example of such
heterogeneity is in health system risk modeling efforts where different
combinations of comorbidities fundamentally alter the relationship between
covariates and health outcomes. Accounting for heterogeneity arising
combinations of factors can yield more accurate and interpretable regression
models. Yet, in the presence of high dimensional covariates, accounting for
this type of heterogeneity can exacerbate estimation difficulties even with
large sample sizes. To handle these issues, we propose a flexible and
interpretable risk modeling approach based on semiparametric sufficient
dimension reduction. The approach accounts for patient heterogeneity, borrows
strength in estimation across related subpopulations to improve both estimation
efficiency and interpretability, and can serve as a useful exploratory tool or
as a powerful predictive model. In simulated examples, we show that our
approach often improves estimation performance in the presence of heterogeneity
and is quite robust to deviations from its key underlying assumptions. We
demonstrate our approach in an analysis of hospital admission risk for a large
health system and demonstrate its predictive power when tested on further
follow-up data.
| [
"stat.ME"
] | stat.ME | Methodology | 4,557Methodology
|
|
cond-mat/0012210 | In this brief tutorial review, I show how phase coherent properties of
disordered conductors can be described in a simple and unified way. These
properties include transport properties like weak-localization correction and
universal conductance fluctuations, and thermodynamic properties like orbital
magnetism and persistent currents. They can be related to the classical return
probability for a diffusive particle. For a network with $N$ nodes, the return
probability can be related to the determinant of a $N \times N$ "connectivity"
matrix $M$ so that the magnetization and the transport quantities can be {\it
directly} written in term of $\det M$.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
1503.04913 | An important property of programming language semantics is that they should
be compositional. However, unstructured low-level code contains goto-like
commands making it hard to define a semantics that is compositional. In this
paper, we follow the ideas of Saabas and Uustalu to structure low-level code.
This gives us the possibility to define a compositional denotational semantics
based on least fixed points to allow for the use of inductive verification
methods. We capture the semantics of communication using finite traces similar
to the denotations of CSP. In addition, we examine properties of this semantics
and give an example that demonstrates reasoning about communication and jumps.
With this semantics, we lay the foundations for a proof calculus that captures
both, the semantics of unstructured low-level code and communication.
| [
"cs.PL",
"cs.LO"
] | cs.PL | cs.LO | Programming Languages;Logic in Computer Science | 5,816Programming Languages;Logic in Computer Science
|
cond-mat/9607147 | We construct a new representation of composite fermion wave functions in the
lowest Landau level which enables Monte Carlo computations at arbitrary filling
factors for a fairly large number of composite fermions, thus clearing the way
toward a more detailed quantitative investigation of the fractional quantum
Hall effect. As an illustrative application, thermodynamic estimates for the
transport gaps of several spin polarized incompressible states have been
obtained.
| [
"cond-mat"
] | cond-mat | Condensed Matter | 1,697Condensed Matter
|
|
2311.04669 | Collective actuation describes the spontaneous synchronized oscillations
taking place in active solids, when the elasto-active feedback, that
generically couples the reorientation of the active forces and the elastic
stress, is large enough. In the absence of noise, collective actuation takes
the form of a strong condensation of the dynamics on a specific pair of modes
and their generalized harmonics. Here we report new experiments conducted with
centimetric active elastic structures, where collective oscillation takes place
along the single lowest energy mode of the system, gapped from the other modes
because of the system's geometry. Combining the numerical and theoretical
analysis of an agent-based model, we demonstrate that this new form of
collective actuation is noise-induced. The effect of the noise is first
analyzed in a single-particle toy model that reveals the interplay between the
noise and the specific structure of the phase space. We then show that in the
continuous limit, any finite amount of noise turns this new form of transition
to collective actuation into a bona fide supercritical Hopf bifurcation.
| [
"cond-mat.soft"
] | cond-mat.soft | Soft Condensed Matter | 6,537Soft Condensed Matter
|
|
1302.3552 | We developed the language of Modifiable Temporal Belief Networks (MTBNs) as a
structural and temporal extension of Bayesian Belief Networks (BNs) to
facilitate normative temporal and causal modeling under uncertainty. In this
paper we present definitions of the model, its components, and its fundamental
properties. We also discuss how to represent various types of temporal
knowledge, with an emphasis on hybrid temporal-explicit time modeling, dynamic
structures, avoiding causal temporal inconsistencies, and dealing with models
that involve simultaneously actions (decisions) and causal and non-causal
associations. We examine the relationships among BNs, Modifiable Belief
Networks, and MTBNs with a single temporal granularity, and suggest areas of
application suitable to each one of them.
| [
"cs.AI"
] | cs.AI | Artificial Intelligence | 361Artificial Intelligence
|
|
cond-mat/0507680 | We investigate theoretically electron transfer in a doble dot in a situation
where it is governed by nuclear magnetic field: This has been recently achieved
in experiment. We show how to partially compensate the nuclear magnetic field
to restore Spin Blockade.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
cond-mat/0105377 | The generation of dark solitons in Bose-Einstein condensates with phase
imprinting is studied by mapping it into the classic problem of a damped driven
pendulum. We provide simple but powerful schemes of designing the phase imprint
for various desired outcomes. We derive a formula for the number of dark
solitons generated by a given phase step, and also obtain results which explain
experimental observations.
| [
"cond-mat"
] | cond-mat | Condensed Matter | 1,697Condensed Matter
|
|
1108.5819 | There are two silver perovskite oxides: AgNbO3 and AgTaO3. AgNbO3 has a
noncentrosymmetric group of Pmc21 at room temperature with a ferri-electric
ordering of polarization. Such a ferri-electric state with small polarization
can be changed into a ferroelectric state with very large polarization by a
high electric field or by a chemical modification. The induced ferroelectric
phase shows promising electromechanical response for applications in
piezoelectric devices. In contrast, AgTaO3 is a quantum paraelectric, but
ferroelectricity also can be induced through chemical substitution. The
findings of good ferroelectric and piezoelectric performance in the silver
perovskites are hoped to trigger further theoretical and experimental
investigations on these systems.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
1210.0113 | We estimate the resource requirements for the quantum simulation of the
ground state energy of the one dimensional quantum transverse Ising model
(TIM), based on the surface code implementation of a fault tolerant quantum
computer. The surface code approach has one of the highest known tolerable
error rates (1%) which makes it currently one of the most practical quantum
computing schemes. Compared to results of the same model using the concatenated
Steane code, the current results indicate that the simulation time is
comparable but the number of physical qubits for the surface code is 2-3 orders
of magnitude larger than that of the concatenation code. Considering that the
error threshold requirements of the surface code is four orders of magnitude
higher than the concatenation code, building a quantum computer with a surface
code implementation appears more promising given current physical hardware
capabilities.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
2207.02867 | We investigate a minimal singlet-scalar extension to the Standard Model that
achieves a strong first-order electroweak phase transition. The singlet can be
naturally light because of an approximate shift symmetry and no extra hierarchy
problem beyond that of the Standard Model Higgs is introduced. We discuss the
two-field dynamics of the phase transition in detail and find that the
gravitational-wave signal is too weak to be detected by near-future
observations. We also discuss the meta-stability of the zero-temperature scalar
potential. Despite the apparent instability just above the electroweak scale,
we show that the lifetime of the electroweak vacuum is much longer than the age
of the universe and hence the setup does not require UV completion near the
electroweak scale. The baryon asymmetry of the universe may be explained by
local electroweak baryogenesis arising from a coupling between the singlet and
weak gauge boson. The predicted electron electric dipole moment is much below
the current bound. The viable parameter space can be probed by the observations
of rare Kaon decay and the cosmic microwave background.
| [
"hep-ph",
"astro-ph.CO"
] | hep-ph | astro-ph.CO | High Energy Physics - Phenomenology;Cosmology and Nongalactic Astrophysics | 3,156High Energy Physics - Phenomenology;Cosmology and Nongalactic Astrophysics
|
1512.07618 | We propose a phenomenological theory working out light illumination effects
on the equilibrium values of any macroscopic crystal tensor (polarization,
magnetization, susceptibilities, strain tensor, elastic coefficients...). it
also encompasses non-equilibrium light-induced quantities such as an electric
current and heat flow. We use a single phenomenological approach based on
Wigner spherical functions for predicting symmetry-related photo-induced
phenomena, including photovoltaic, photoelectric, photomagnetic,
photorefractive, photogalvanic, photoelastic and optic rectification phenomena.
For each crystal magnetic point group and each tensor type, response functions
are calculated vs. the propagation and polarization directions of the incident
electromagnetic beam. Their forms are determined by crystal and light symmetry
group interconnection. We pay special attention to time and space reversal
symmetries, which play a dominant role in the intricate symmetry breakdowns of
multiferroic materials. Photovoltaic and photo-magneto-electric effects in
LiNbO3 illustrate our theory.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
2112.15205 | In the late 80s, V.~Arnold and V.~Vassiliev initiated the topological study
of the space of real univariate polynomials of a given degree which have no
real roots of multiplicity exceeding a given positive integer. Expanding their
studies, we consider the spaces P^{c\Theta}_d of real monic univariate
polynomials of degree d whose real divisors avoid given sequences of root
multiplicities. These forbidden sequences are taken from an arbitrary poset
\Theta of compositions that are closed under certain natural combinatorial
operations. We reduce the computation of the homology H_*(P^{c\Theta}_d) to the
computation of the homology of a differential complex, defined purely
combinatorially in terms of the given closed poset \Theta. We also obtain the
stabilization results about H^\ast(P^{c \Theta}_d), as d goes to infinity.
These results are deduced from our description of the homology of spaces B^{c
\Theta}_d whose points are binary real homogeneous forms, considered up to
projective equivalence, with similarly \Theta-constrained real divisors. In
particular, we exhibit differential complexes that calculate the homology of
these spaces and obtain some stabilization results for H^*(B^{c \Theta}_d), as
d goes to infinity. In particular, we compute the homology of the discriminants
of projectivized binary real forms for which there is at least one line on
which the form vanishes with multiplicity >= 2 and of their complements in
\cB_d \cong RP^d.
| [
"math.AT",
"math.CO"
] | math.AT | math.CO | Algebraic Topology;Combinatorics | 171Algebraic Topology;Combinatorics
|
1703.10524 | The colonic mucus layer is a dynamic and complex structure formed by secreted
and transmembrane mucins, which are high-molecular-weight and heavily
glycosylated proteins. Colonic mucus consists of a loose outer layer and a
dense epithelium-attached layer. The outer layer is inhabited by various
representatives of the human gut microbiota (HGM). Glycans of the colonic mucus
can be used by the HGM as a source of carbon and energy when dietary fibers are
not sufficiently available. Here, we analyzed 397 individual HGM genomes to
identify pathways for the cleavage of host-synthetized mucin glycans to
monosaccharides as well as for the catabolism of the derived monosaccharides.
Our key results are as follows: (i) Genes for the cleavage of mucin glycans
were found in 86% of the analyzed genomes, whereas genes for the catabolism of
derived monosaccharides were found in 89% of the analyzed genomes. (ii)
Comparative genomic analysis identified four alternative forms of the
monosaccharide-catabolizing enzymes and four alternative forms of
monosaccharide transporters. (iii) Eighty-five percent of the analyzed genomes
may be involved in exchange pathways for the monosaccharides derived from
cleaved mucin glycans. (iv) The analyzed genomes demonstrated different
abilities to degrade known mucin glycans. Generally, the ability to degrade at
least one type of mucin glycan was predicted for 81% of the analyzed genomes.
(v) Eighty-two percent of the analyzed genomes can form mutualistic pairs that
are able to degrade mucin glycans and are not degradable by any of the paired
organisms alone. Taken together, these findings provide further insight into
the inter-microbial communications of the HGM as well as into host-HGM
interactions.
| [
"q-bio.GN"
] | q-bio.GN | Genomics | 2,797Genomics
|
|
1601.03954 | The multi-valued quantum $j$-invariant in positive characteristic is studied
at quadratic elements. For every quadratic $f$, an explicit expression for each
of the values of $j^{\rm qt}(f)$ is given as a limit of rational functions of
$f$. It is proved that the number of values of $j^{\rm qt}(f)$ is finite and
that none of these values is $\infty$.
| [
"math.NT"
] | math.NT | Number Theory | 4,945Number Theory
|
|
2007.05612 | Arabic dialect identification is a complex problem for a number of inherent
properties of the language itself. In this paper, we present the experiments
conducted, and the models developed by our competing team, Mawdoo3 AI, along
the way to achieving our winning solution to subtask 1 of the Nuanced Arabic
Dialect Identification (NADI) shared task. The dialect identification subtask
provides 21,000 country-level labeled tweets covering all 21 Arab countries. An
unlabeled corpus of 10M tweets from the same domain is also presented by the
competition organizers for optional use. Our winning solution itself came in
the form of an ensemble of different training iterations of our pre-trained
BERT model, which achieved a micro-averaged F1-score of 26.78% on the subtask
at hand. We publicly release the pre-trained language model component of our
winning solution under the name of Multi-dialect-Arabic-BERT model, for any
interested researcher out there.
| [
"cs.CL",
"cs.LG"
] | cs.CL | cs.LG | Computation and Language;Machine Learning | 1,237Computation and Language;Machine Learning
|
2206.00748 | In this paper we present photometric redshifts for 2.7 million galaxies in
the XMM-LSS and COSMOS fields, both with rich optical and near-infrared data
from VISTA and HyperSuprimeCam. Both template fitting (using galaxy and Active
Galactic Nuclei templates within LePhare) and machine learning (using GPz)
methods are run on the aperture photometry of sources selected in the Ks-band.
The resulting predictions are then combined using a Hierarchical Bayesian
model, to produce consensus photometric redshift point estimates and
probability distribution functions that outperform each method individually.
Our point estimates have a root mean square error of ~0.08-0.09, and an outlier
fraction of ~3-4 percent when compared to spectroscopic redshifts. We also
compare our results to the COSMOS2020 photometric redshifts, which contains
fewer sources, but had access to a larger number of bands and greater
wavelength coverage, finding that comparable photo-z quality can be achieved
(for bright and intermediate luminosity sources where a direct comparison can
be made). Our resulting redshifts represent the most accurate set of
photometric redshifts (for a catalogue this large) for these deep multi-square
degree multi-wavelength fields to date.
| [
"astro-ph.GA"
] | astro-ph.GA | Astrophysics of Galaxies | 464Astrophysics of Galaxies
|
|
0706.3856 | The Lovasz extension of a pseudo-Boolean function $f : \{0,1\}^n \to R$ is
defined on each simplex of the standard triangulation of $[0,1]^n$ as the
unique affine function $\hat f : [0,1]^n \to R$ that interpolates $f$ at the
$n+1$ vertices of the simplex. Its degree is that of the unique multilinear
polynomial that expresses $f$. In this paper we investigate the least squares
approximation problem of an arbitrary Lovasz extension $\hat f$ by Lovasz
extensions of (at most) a specified degree. We derive explicit expressions of
these approximations. The corresponding approximation problem for
pseudo-Boolean functions was investigated by Hammer and Holzman (1992) and then
solved explicitly by Grabisch, Marichal, and Roubens (2000), giving rise to an
alternative definition of Banzhaf interaction index. Similarly we introduce a
new interaction index from approximations of $\hat f$ and we present some of
its properties. It turns out that its corresponding power index identifies with
the power index introduced by Grabisch and Labreuche (2001).
| [
"math.CO",
"cs.DM"
] | math.CO | cs.DM | Combinatorics;Discrete Mathematics | 1,049Combinatorics;Discrete Mathematics
|
astro-ph/0610725 | Ultra High Energy (UHE) Cosmic Rays, UHECR, may graze high altitude
atmosphere leading to horizontal upward air-showers. Also PeVs electron
antineutrino hitting electron in atmosphere may air-shower at W boson resonant
mass. On the other side ultra high energy muon and electron neutrinos may also
lead, by UHE neutrinos mass state mixing, to the rise of a corresponding UHE
Tau neutrino flavor; the consequent UHE tau neutrinos, via charge current
interactions in matter, may create UHE taus at horizons (Earth skimming
neutrinos or Hor-taus) whose escape in atmosphere and whose consequent decay in
flight, may be later amplified by upward showering on terrestrial, planetary
atmospheres. Indeed because of the finite terrestrial radius, its thin
atmosphere size its dense crust, the UHE tau cannot extend much more than 360
kilometers in air, corresponding to an energy of about 7.2 EeV, near but below
GZK cut-off ones; on the contrary Jupiter (or even Saturn) may offer a wider,
less dense and thicker gaseous layer at the horizons where Tau may loose little
energy, travel longer before decay and rise and shower at 4-6 10^{19} eV or ZeV
extreme energy. Titan atmosphere may open a rare window of opportunity for
Up-ward Taus at PeVs. Also solar atmosphere may play a role, but unfortunately
tau-showers secondaries maybe are too noisy to be disentangled, while Jupiter
atmosphere, or better, Saturn one, may offer a clearer imprint for GZK (and
higher Z-Burst) Tau showering, well below the horizons edges.
| [
"astro-ph",
"hep-ph",
"physics.ao-ph",
"physics.geo-ph"
] | astro-ph | hep-ph | Astrophysics;High Energy Physics - Phenomenology;Atmospheric and Oceanic Physics;Geophysics | 7,267longtail
|
0712.1088 | A series of endofullerenes Ag@C60 with different symmetry are calculated at
ab initio level. The lowest energy structure is completely asymmetrical one
(C1), in which the endo-atom has noticeably off-centre position. The
symmetrical structures are less stable. Silver atom in the Ag@C60 (C1)
endofullerene has the low negative charge and high spin density.
| [
"cond-mat.other"
] | cond-mat.other | Other Condensed Matter | 5,360Other Condensed Matter
|
|
adap-org/9405001 | Individuals in groups must often choose between acting selfishly and
cooperating for the common good. The choices they make are based on their
beliefs on how they expect their actions to affect others. We show that for a
broad set of beliefs and group characteristics cooperation can appear
spontaneously in non-cooperative groups after very long periods of time. When
delays in information are unavoidable the group dynamics acquires a wide
repertoire of behaviors, ranging from opportunistic oscillations to bursty
chaos, thus excluding the possibility of sustained cooperation.
| [
"adap-org",
"nlin.AO"
] | adap-org | nlin.AO | Adaptation, Noise, and Self-Organizing Systems;Adaptation and Self-Organizing Systems | 44Adaptation, Noise, and Self-Organizing Systems;Adaptation and Self-Organizing Systems
|
2010.10053 | We study syzygies of abelian varieties via the methods of Caucci and Ito
based on computations of cohomological rank functions. We provide some strong
evidences to a conjecture of Ito and Lozovanu.
| [
"math.AG"
] | math.AG | Algebraic Geometry | 47Algebraic Geometry
|
|
astro-ph/0309295 | We present results from a Keck spectroscopic survey of red giants in a field
near M31's major axis, ~34kpc in projection from the nucleus, near the globular
cluster G1. We use multislit LRIS spectroscopy to measure the CaII triplet in
41 stars with apparent mags 20<I<22. Of these, 23 stars are found to have
radial velocities v<-200km/s indicating they are giants in M31; the rest are
probably foreground Galactic stars. About 2/3 of the M31 members concentrate at
v=-451km/s, with a velocity spread of sigma=27km/s, which suggests that they
belong to the outer disk or perhaps a cold debris trail in the halo. The
group's mean velocity is consistent with that of nearby HI gas and models of
M31's disk velocity field but not with G1 or M31's systemic velocity. We use
V,I photometry to estimate a mean metallicity of <[Fe/H]>=-0.8 for these
potential M31 outer disk stars. Six of the 23 M31 members v and [Fe/H] values
consistent with those of G1 (after accounting forits intrinsic spread in both):
one of these stars lies within G1's projected tidal radius and is a likely
member; the remaining 5 stars are not physically close to G1 but may represent
its tidal debris. More data are needed to confirm the nature of these 5 stars
as it is likely that they represent M31's smooth halo population. We might have
expected to detect tidal debris if G1 were the remnant core of a dwarf galaxy
being accreted by M31; instead, the majority of M31 giants in this field are
metal-rich and belong to what is evidently the outer disk of M31, and only a
small fraction (<~20%) could possibly have originated in G1.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2203.04769 | In the classic machine learning framework, models are trained on historical
data and used to predict future values. It is assumed that the data
distribution does not change over time (stationarity). However, in real-world
scenarios, the data generation process changes over time and the model has to
adapt to the new incoming data. This phenomenon is known as concept drift and
leads to a decrease in the predictive model's performance. In this study, we
propose a new concept drift detection method based on autoregressive models
called ADDM. This method can be integrated into any machine learning algorithm
from deep neural networks to simple linear regression model. Our results show
that this new concept drift detection method outperforms the state-of-the-art
drift detection methods, both on synthetic data sets and real-world data sets.
Our approach is theoretically guaranteed as well as empirical and effective for
the detection of various concept drifts. In addition to the drift detector, we
proposed a new method of concept drift adaptation based on the severity of the
drift.
| [
"stat.ML",
"cs.LG"
] | stat.ML | cs.LG | Machine Learning;Machine Learning | 4,163Machine Learning;Machine Learning
|
1904.06590 | We present a deep learning method for singing voice conversion. The proposed
network is not conditioned on the text or on the notes, and it directly
converts the audio of one singer to the voice of another. Training is performed
without any form of supervision: no lyrics or any kind of phonetic features, no
notes, and no matching samples between singers. The proposed network employs a
single CNN encoder for all singers, a single WaveNet decoder, and a classifier
that enforces the latent representation to be singer-agnostic. Each singer is
represented by one embedding vector, which the decoder is conditioned on. In
order to deal with relatively small datasets, we propose a new data
augmentation scheme, as well as new training losses and protocols that are
based on backtranslation. Our evaluation presents evidence that the conversion
produces natural signing voices that are highly recognizable as the target
singer.
| [
"cs.LG",
"cs.SD",
"eess.AS",
"stat.ML"
] | cs.LG | cs.SD | Machine Learning;Sound;Audio and Speech Processing;Machine Learning | 4,271Machine Learning;Sound;Audio and Speech Processing;Machine Learning
|
1609.05790 | We investigate the scaling behavior of longitudinal and transverse structure
functions in homogeneous and isotropic magneto-hydrodynamic (MHD) turbulence by
means of an exact hierarchy of structure function equations as well as by
direct numerical simulations of two- and three-dimensional MHD turbulence. In
particular, rescaling relations between longitudinal and transverse structure
functions are derived and utilized in order to compare different scaling
behavior in the inertial range. It is found that there are no substantial
differences between longitudinal and transverse structure functions in MHD
turbulence. This finding stands in contrast to the case of hydrodynamic
turbulence which shows persistent differences even at high Reynolds numbers. We
propose a physical picture that is based on an effective reduction of pressure
contributions due to local regions of same magnitude and alignment of velocity
and magnetic field fluctuations. Finally, our findings underline the importance
of the pressure term for the actually observed scaling differences in
hydrodynamic turbulence.
| [
"physics.flu-dyn",
"physics.plasm-ph"
] | physics.flu-dyn | physics.plasm-ph | Fluid Dynamics;Plasma Physics | 2,503Fluid Dynamics;Plasma Physics
|
1302.0974 | Canonical correlation analysis is a statistical technique that is used to
find relations between two sets of variables. An important extension in pattern
analysis is to consider more than two sets of variables. This problem can be
expressed as a quadratically constrained quadratic program (QCQP), commonly
referred to Multi-set Canonical Correlation Analysis (MCCA). This is a
non-convex problem and so greedy algorithms converge to local optima without
any guarantees on global optimality. In this paper, we show that despite being
highly structured, finding the optimal solution is NP-Hard. This motivates our
relaxation of the QCQP to a semidefinite program (SDP). The SDP is convex, can
be solved reasonably efficiently and comes with both absolute and
output-sensitive approximation quality. In addition to theoretical guarantees,
we do an extensive comparison of the QCQP method and the SDP relaxation on a
variety of synthetic and real world data. Finally, we present two useful
extensions: we incorporate kernel methods and computing multiple sets of
canonical vectors.
| [
"cs.LG"
] | cs.LG | Machine Learning | 3,882Machine Learning
|
|
1308.6826 | When a single molecule is detected in a wide-field microscope, the image
approximates the point spread function of the system. However, as the
distribution of molecules becomes denser and their images begin to coincide,
existing solutions to determine the number of molecules present and their
precise three-dimensional locations can tolerate little to no overlap. A
solution to this problem involving matched optical and digital techniques, as
here proposed, is critical to increase the allowable labeling density and to
accelerate single-molecule localization microscopy.
| [
"physics.optics",
"q-bio.QM"
] | physics.optics | q-bio.QM | Optics;Quantitative Methods | 5,222Optics;Quantitative Methods
|
astro-ph/0604184 | We present new X-ray and optical spectroscopy of a Type 2 quasar candidate
selected from a follow-up program of hard, optically-dim, serendipitous Chandra
sources. The source is confirmed to be a Type 2 quasar at z=0.536 with an
intrinsic 2-10 keV luminosity L_{2-10}=5x10^{44} h_{0.7}^{-2} erg/s, an
absorbing column density N_H=8x10^{23} cm^{-2} and a neutral Fe K alpha line
detected by XMM-Newton EPIC-MOS1 as well as Chandra ACIS-S. An extended optical
forbidden emission line cloud is detected at the same redshift, and at about 15
kpc in projected separation. This cloud lies in close proximity to the peak of
the compact steep spectrum radio source 4C+39.29, which has previously been
identified with a foreground galaxy in the cluster Abell 963. We present
evidence to show that 4C+39.29 is associated with the background X-ray Type 2
quasar. The radio luminosity is dominated by lobes with complex structure and
the radio core is weak in comparison to narrow-line radio galaxies at the same
X-ray luminosity. The morphology and emission line properties of the extended
region are consistent with an on-going jet-cloud interaction. 4C+39.29
possesses a combination of high power and high absorbing column density
compared with other X-ray Type 2 quasars in the literature. These observations
highlight the efficacy of using X-rays to identify the primary energy source of
complex radio sources and distant obscured AGN.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
1003.1601 | The outcome of competition among species is influenced by the spatial
distribution of species and effects such as demographic stochasticity,
immigration fluxes, and the existence of preferred habitats. We introduce an
individual-based model describing the competition of two species and
incorporating all the above ingredients. We find that the presence of habitat
preference --- generating spatial niches --- strongly stabilizes the
coexistence of the two species. Eliminating habitat preference --- neutral
dynamics --- the model generates patterns, such as distribution of population
sizes, practically identical to those obtained in the presence of habitat
preference, provided an higher immigration rate is considered. Notwithstanding
the similarity in the population distribution, we show that invasibility
properties depend on habitat preference in a non-trivial way. In particular,
the neutral model results results more invasible or less invasible depending on
whether the comparison is made at equal immigration rate or at equal
distribution of population size, respectively. We discuss the relevance of
these results for the interpretation of invasibility experiments and the
species occupancy of preferred habitats.
| [
"q-bio.PE",
"cond-mat.stat-mech"
] | q-bio.PE | cond-mat.stat-mech | Populations and Evolution;Statistical Mechanics | 5,674Populations and Evolution;Statistical Mechanics
|
astro-ph/0411357 | We present the results of spectroscopic observations of targets discovered
during the first two years of the ESSENCE project. The goal of ESSENCE is to
use a sample of ~200 Type Ia supernovae (SNe Ia) at moderate redshifts (0.2 < z
< 0.8) to place constraints on the equation of state of the Universe.
Spectroscopy not only provides the redshifts of the objects, but also confirms
that some of the discoveries are indeed SNe Ia. This confirmation is critical
to the project, as techniques developed to determine luminosity distances to
SNe Ia depend upon the knowledge that the objects at high redshift are the same
as the ones at low redshift. We describe the methods of target selection and
prioritization, the telescopes and detectors, and the software used to identify
objects. The redshifts deduced from spectral matching of high-redshift SNe Ia
with low-redshift SNe Ia are consistent with those determined from host-galaxy
spectra. We show that the high-redshift SNe Ia match well with low-redshift
templates. We include all spectra obtained by the ESSENCE project, including 52
SNe Ia, 5 core-collapse SNe, 12 active galactic nuclei, 19 galaxies, 4 possibly
variable stars, and 16 objects with uncertain identifications.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
1405.7951 | Oriented loops on an orientable surface are, up to equivalence by free
homotopy, in one-to-one correspondence with the conjugacy classes of the
surface's fundamental group. These conjugacy classes can be expressed (not
uniquely in the case of closed surfaces) as a cyclic word of minimal length in
terms of the fundamental group's generators. The self-intersection number of a
conjugacy class is the minimal number of transverse self-intersections of
representatives of the class. By using Markov chains to encapsulate the
exponential mixing of the geodesic flow and achieve sufficient independence, we
can use a form of the central limit theorem to describe the statistical nature
of the self-intersection number. For a class chosen at random among all classes
of length n, the distribution of the self intersection number approaches a
Gaussian when n is large. This theorem generalizes the result of Steven Lalley
and Moira Chas to include the case of closed surfaces.
| [
"math.DS"
] | math.DS | Dynamical Systems | 2,265Dynamical Systems
|
|
0804.2986 | The first part of this paper considers higher order CR invariants of three
dimensional hypersurfaces of finite type. Using a full normal form we give a
complete characterization of hypersurfaces with trivial local automorphism
group, and analogous results for finite groups. The second part considers
hypersurfaces of finite Catlin multitype and the Kohn-Nirenberg phenomenon in
higher dimensions. We give a necessary condition for local convexifiability of
a class of pseudoconvex hypersurfaces in $\mathbb C^{n+1}$.
| [
"math.CV"
] | math.CV | Complex Variables | 1,135Complex Variables
|
|
2206.09123 | In this paper we study the influence of including snapshots that approach the
velocity time derivative in the numerical approximation of the incompressible
Navier-Stokes equations by means of proper orthogonal decomposition (POD)
methods. Our set of snapshots includes the velocity approximation at the
initial time from a full order mixed finite element method (FOM) together with
approximations to the time derivative at different times. The approximation at
the initial velocity can be replaced by the mean value of the velocities at the
different times so that implementing the method to the fluctuations, as done
mostly in practice, only approximations to the time derivatives are included in
the set of snapshots. For the POD method we study the differences between
projecting onto $L^2$ and $H^1$. In both cases pointwise in time error bounds
can be proved. Including grad-div stabilization both in the FOM and POD methods
error bounds with constants independent on inverse powers of the viscosity can
be obtained.
| [
"math.NA",
"cs.NA"
] | math.NA | cs.NA | Numerical Analysis;Numerical Analysis | 5,059Numerical Analysis;Numerical Analysis
|
2309.16798 | One prerequisite for supervised machine learning is high quality labelled
data. Acquiring such data is, particularly if expert knowledge is required,
costly or even impossible if the task needs to be performed by a single expert.
In this paper, we illustrate tool support that we adopted and extended to
source domain-specific knowledge from experts. We provide insight in design
decisions that aim at motivating experts to dedicate their time at performing
the labelling task. We are currently using the approach to identify true
synonyms from a list of candidate synonyms. The identification of synonyms is
important in scenarios were stakeholders from different companies and
background need to collaborate, for example when defining and negotiating
requirements. We foresee that the approach of expert-sourcing is applicable to
any data labelling task in software engineering. The discussed design decisions
and implementation are an initial draft that can be extended, refined and
validated with further application.
| [
"cs.SE"
] | cs.SE | Software Engineering | 6,626Software Engineering
|
|
1302.5405 | The open subvariety $\overline{M}_g^{\leq k}$ of $\overline{M}_g$
parametrizes stable curves of genus $g$ having at most $k$ rational components.
By the work of Looijenga, one expects that the cohomological excess of
$\overline{M}_g^{\leq k}$ is at most $g-1+k$. In this paper we show that when
$k=0$, the conjectured upper bound is sharp by showing that there is a
constructible sheaf on $\overline{H}_g^{\leq k}$ (the hyperelliptic locus)
which has non-vanishing cohomology in degree $3g-2$.
| [
"math.AG"
] | math.AG | Algebraic Geometry | 47Algebraic Geometry
|
|
cond-mat/9810292 | We propose a way of extending the Broad Histogram Monte Carlo method (BHMC)
to systems with continuous degrees of freedom, and we apply these ideas to
investigate the three-dimensional XY-model. Our method gives results in
excellent agreement with Metropolis and Histogram Monte Carlo simulations and
calculates for the whole temperature range 1.2<T<4.7 using only 2 times more
computer effort than the Histogram method for the range 2.1<T<2.2. Our way of
treatment is general, it can also be applied to other systems with continuous
degrees of freedom.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
2311.14272 | Machine learning pipelines for classification tasks often train a universal
model to achieve accuracy across a broad range of classes. However, a typical
user encounters only a limited selection of classes regularly. This disparity
provides an opportunity to enhance computational efficiency by tailoring models
to focus on user-specific classes. Existing works rely on unstructured pruning,
which introduces randomly distributed non-zero values in the model, making it
unsuitable for hardware acceleration. Alternatively, some approaches employ
structured pruning, such as channel pruning, but these tend to provide only
minimal compression and may lead to reduced model accuracy. In this work, we
propose CRISP, a novel pruning framework leveraging a hybrid structured
sparsity pattern that combines both fine-grained N:M structured sparsity and
coarse-grained block sparsity. Our pruning strategy is guided by a
gradient-based class-aware saliency score, allowing us to retain weights
crucial for user-specific classes. CRISP achieves high accuracy with minimal
memory consumption for popular models like ResNet-50, VGG-16, and MobileNetV2
on ImageNet and CIFAR-100 datasets. Moreover, CRISP delivers up to 14$\times$
reduction in latency and energy consumption compared to existing pruning
methods while maintaining comparable accuracy. Our code is available at
https://github.com/shivmgg/CRISP/.
| [
"cs.CV",
"cs.AR",
"cs.LG"
] | cs.CV | cs.AR | Computer Vision and Pattern Recognition;Hardware Architecture;Machine Learning | 1,578Computer Vision and Pattern Recognition;Hardware Architecture;Machine Learning
|
1104.3232 | The equilibration dynamics of a closed quantum system is encoded in the
long-time distribution function of generic observables. In this paper we
consider the Loschmidt echo generalized to finite temperature, and show that we
can obtain an exact expression for its long-time distribution for a closed
system described by a quantum XY chain following a sudden quench. In the
thermodynamic limit the logarithm of the Loschmidt echo becomes normally
distributed, whereas for small quenches in the opposite, quasi-critical regime,
the distribution function acquires a universal double-peaked form indicating
poor equilibration. These findings, obtained by a central limit theorem-type
result, extend to completely general models in the small-quench regime.
| [
"quant-ph",
"cond-mat.stat-mech"
] | quant-ph | cond-mat.stat-mech | Quantum Physics;Statistical Mechanics | 6,184Quantum Physics;Statistical Mechanics
|
1203.3893 | We derive the time-evolution equation that describes the Brownian motion of
labeled individual tracer particles in a simple model atomic liquid (i.e., a
system of $N$ particles whose motion is governed by Newton's second law, and
interacting through spherically symmetric pairwise potentials). We base our
derivation on the generalized Langevin equation formalism, and find that the
resulting time evolution equation is formally identical to the generalized
Langevin equation that describes the Brownian motion of individual tracer
particles in a colloidal suspension in the absence of hydrodynamic
interactions. This formal dynamic equivalence implies the long-time
indistinguishability of some dynamic properties of both systems, such as their
mean squared displacement, upon a well-defined time scaling. This prediction is
tested here by comparing the results of molecular and Brownian dynamics
simulations performed on the hard sphere system.
| [
"cond-mat.soft"
] | cond-mat.soft | Soft Condensed Matter | 6,537Soft Condensed Matter
|
|
math/0702473 | In these notes, we present some methods and applications of large deviations
to finance and insurance. We begin with the classical ruin problem related to
the Cramer's theorem and give en extension to an insurance model with
investment in stock market. We then describe how large deviation approximation
and importance sampling are used in rare event simulation for option pricing.
We finally focus on large deviations methods in risk management for the
estimation of large portfolio losses in credit risk and portfolio performance
in market investment.
| [
"math.PR",
"q-fin.ST"
] | math.PR | q-fin.ST | Probability;Statistical Finance | 5,790Probability;Statistical Finance
|
0912.1990 | We discuss cooling of a nanomechanical resonator to its mechanical ground
state by coupling it to a collective system of two interacting flux qubits. We
find that the collectivity crucially improves cooling by two mechanisms. First,
cooling transitions proceed via sub-radiant Dicke states, and the reduced line
width of these sub-radiant states suppresses both the scattering and the
environmental contribution to the final phonon number. Second, detrimental
carrier excitations without change in the motion of the resonator are
suppressed by collective energy shifts.
| [
"quant-ph",
"cond-mat.supr-con"
] | quant-ph | cond-mat.supr-con | Quantum Physics;Superconductivity | 6,210Quantum Physics;Superconductivity
|
1111.4898 | Human navigation has been a topic of interest in spatial cognition from the
past few decades. It has been experimentally observed that humans accomplish
the task of way-finding a destination in an unknown environment by recognizing
landmarks. Investigations using network analytic techniques reveal that humans,
when asked to way-find their destination, learn the top ranked nodes of a
network. In this paper we report a study simulating the strategy used by humans
to recognize the centers of a network. We show that the paths obtained from our
simulation has the same properties as the paths obtained in human based
experiment. The simulation thus performed leads to a novel way of path-finding
in a network. We discuss the performance of our method and compare it with the
existing techniques to find a path between a pair of nodes in a network.
| [
"cs.SI",
"physics.soc-ph"
] | cs.SI | physics.soc-ph | Social and Information Networks;Physics and Society | 6,526Social and Information Networks;Physics and Society
|
2012.06091 | Under weak illumination, tracking and imaging moving object turns out to be
hard. By spatially collecting the signal, single pixel imaging schemes promise
the capability of image reconstruction from low photon flux. However, due to
the requirement on large number of samplings, how to clearly image moving
objects is an essential problem for such schemes. Here we present a principle
of single pixel tracking and imaging method. Velocity vector of the object is
obtained from temporal correlation of the bucket signals in a typical
computational ghost imaging system. Then the illumination beam is steered
accordingly. Taking the velocity into account, both trajectory and clear image
of the object are achieved during its evolution. Since tracking is achieved
with bucket signals independently, this scheme is valid for capturing moving
object as fast as its displacement within the interval of every sampling keeps
larger than the resolution of the optical system. Experimentally, our method
works well with the average number of detected photons down to 1.88
photons/speckle.
| [
"physics.optics",
"eess.IV"
] | physics.optics | eess.IV | Optics;Image and Video Processing | 5,186Optics;Image and Video Processing
|
1908.04733 | In a conformal field theory, two and three-point functions of scalar
operators and conserved currents are completely determined, up to constants, by
conformal invariance. The expressions for these correlators in Euclidean
signature are long known in position space, and were fully worked out in recent
years in momentum space. In Lorentzian signature, the position-space
correlators simply follow from the Euclidean ones by means of the i-epsilon
prescription. In this paper, we compute the Lorentzian correlators in momentum
space and in arbitrary dimensions for three scalar operators by means of a
formal Wick rotation. We explain how tensorial three-point correlators can be
obtained and, in particular, compute the correlator with two identical scalars
and one energy-momentum tensor. As an application, we show that expectation
values of the ANEC operator simplify in this approach.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2305.15951 | Motivated by the important need for computationally tractable statistical
methods in high dimensional spatial settings, we develop a distributed and
integrated framework for estimation and inference of Gaussian model parameters
with ultra-high-dimensional likelihoods. We propose a paradigm shift from whole
to local data perspectives that is rooted in distributed model building and
integrated estimation and inference. The framework's backbone is a
computationally and statistically efficient integration procedure that
simultaneously incorporates dependence within and between spatial resolutions
in a recursively partitioned spatial domain. Statistical and computational
properties of our distributed approach are investigated theoretically and in
simulations. The proposed approach is used to extract new insights on autism
spectrum disorder from the Autism Brain Imaging Data Exchange.
| [
"stat.ME",
"stat.CO"
] | stat.ME | stat.CO | Methodology;Computation | 4,566Methodology;Computation
|
2212.13605 | Let $T$ be a countable complete first-order theory with a definable,
infinite, discrete linear order. We prove that $T$ has continuum-many countable
models. The proof is purely first-order, but raises the question of Borel
completeness of $T$.
| [
"math.LO"
] | math.LO | Logic | 3,800Logic
|
|
1708.01191 | Understanding human activity and being able to explain it in detail surpasses
mere action classification by far in both complexity and value. The challenge
is thus to describe an activity on the basis of its most fundamental
constituents, the individual postures and their distinctive transitions.
Supervised learning of such a fine-grained representation based on elementary
poses is very tedious and does not scale. Therefore, we propose a completely
unsupervised deep learning procedure based solely on video sequences, which
starts from scratch without requiring pre-trained networks, predefined body
models, or keypoints. A combinatorial sequence matching algorithm proposes
relations between frames from subsets of the training data, while a CNN is
reconciling the transitivity conflicts of the different subsets to learn a
single concerted pose embedding despite changes in appearance across sequences.
Without any manual annotation, the model learns a structured representation of
postures and their temporal development. The model not only enables retrieval
of similar postures but also temporal super-resolution. Additionally, based on
a recurrent formulation, next frames can be synthesized.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
2212.11926 | We present model-marginalized limits on mixed hot dark matter scenarios,
which consider both thermal neutrinos and thermal QCD axions. A novel aspect of
our analyses is the inclusion of small-scale Cosmic Microwave Background (CMB)
observations from the Atacama Cosmology Telescope (ACT) and the South Pole
Telescope (SPT), together with those from the Planck satellite and Baryon
Acoustic Oscillation (BAO) data. After marginalizing over a number of
well-motivated non-minimal background cosmologies, the tightest $95\%$ CL upper
bound we obtain is $0.21$ eV, both for $\sum m_\nu$ and $m_{\rm a}$, from the
combination of ACT, Planck and BAO measurements. Restricting the analyses to
the standard $\Lambda$CDM picture, we find $\sum m_\nu<0.16$ eV and $m_{\rm
a}<0.18$ eV, both at $95\%$ CL. Interestingly, the best background cosmology is
never found within the minimal $\Lambda$CDM plus hot relics, regardless of the
data sets exploited in the analyses. The combination of Planck with either BAO,
SPT or ACT prefers a universe with a non-zero value of the running in the
primordial power spectrum with strong evidence. Small-scale CMB probes, both
alone and combined with BAO, either prefer, with substantial evidence, non-flat
universes (as in the case of SPT) or a model with a time varying dark energy
component (as in the case of ACT).
| [
"astro-ph.CO",
"hep-ph"
] | astro-ph.CO | hep-ph | Cosmology and Nongalactic Astrophysics;High Energy Physics - Phenomenology | 1,762Cosmology and Nongalactic Astrophysics;High Energy Physics - Phenomenology
|
1308.5701 | In this paper we consider the density of maximal order elements in
$\mathrm{GL}_n(q)$. Fixing any of the rank $n$ of the group, the characteristic
$p$ or the degree $r$ of the extension of the underlying field $\mathbb{F}_q$
of size $q=p^r$, we compute the expected value of the said density and
establish that it follows a distribution law.
| [
"math.NT",
"math.GR"
] | math.NT | math.GR | Number Theory;Group Theory | 4,984Number Theory;Group Theory
|
2104.14876 | The quest for nonmagnetic Weyl semimetals with high tunability of phase has
remained a demanding challenge. As the symmetry breaking control parameter, the
ferroelectric order can be steered to turn on/off the Weyl semimetals phase,
adjust the band structures around the Fermi level, and enlarge/shrink the
momentum separation of Weyl nodes which generate the Berry curvature as the
emergent magnetic field. Here, we report the realization of a ferroelectric
nonmagnetic Weyl semimetal based on indium doped Pb1 xSnxTe alloy where the
underlying inversion symmetry as well as mirror symmetry is broken with the
strength of ferroelectricity adjustable via tuning indium doping level and
Sn/Pb ratio. The transverse thermoelectric effect, i.e., Nernst effect both for
out of plane and in plane magnetic field geometry, is exploited as a Berry
curvature sensitive experimental probe to manifest the generation of Berry
curvature via the redistribution of Weyl nodes under magnetic fields. The
results demonstrate a clean non-magnetic Weyl semimetal coupled with highly
tunable ferroelectric order, providing an ideal platform for manipulating the
Weyl fermions in nonmagnetic system.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|