cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On the origin of the exponential decay of the Loschmidt echo in integrable systems
Creators: name: Dubertrand, Remy
name: Goussev, Arseni
Publisher: name: arXiv
Year: 2013
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We address the time decay of the Loschmidt echo, measuring sensitivity of quantum dynamics to small Hamiltonian perturbations, in one-dimensional integrable systems. Using semiclassical analysis, we show that the Loschmidt echo may exhibit a well-pronounced regime of exponential decay, alike the one typically observed in quantum systems whose dynamics is chaotic in the classical limit. We derive an explicit formula for the exponential decay rate in terms of the spectral properties of the unperturbed and perturbed Hamilton operators and the initial state. In particular, we show that the decay rate, unlike in the case of the chaotic dynamics, is directly proportional to the strength of the Hamiltonian perturbation. Finally, we compare our analytical predictions against the results of a numerical computation of the Loschmidt echo for a quantum particle moving inside a one-dimensional box with Dirichlet-Robin boundary conditions, and find the two in good agreement.
description: 6 pages, 2 figures
Black Holes, Entanglement and Random Matrices
Creators: name: Balasubramanian, Vijay
name: Berkooz, Micha
name: Ross, Simon F.
name: Simon, Joan
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We provide evidence that strong quantum entanglement between Hilbert spaces does not generically create semiclassical wormholes between the corresponding geometric regions in the context of the AdS/CFT correspondence. We propose a description of low-energy gravity probes as random operators on the space of black hole states. We use this description to compute correlators between the entangled systems, and argue that a wormhole can only exist if correlations are large. Conversely, we also argue that large correlations can exist in the manifest absence of a Lorentzian wormhole. Thus the strength of the entanglement cannot generically diagnose spacetime connectedness, without information on the spectral properties of the probing operators. Our random matrix picture of probes also provides suggestive insights into the problem of "seeing behind a horizon".
description: 25 pages, no figures, v2: references added; v3: mistake in calculation of two-sided correlator corrected
The decays of the fully open flavor state $T_{c\bar{s}0}^{0}$ in a $D^{*}K^{*}$ molecule scenario
Creators: name: Yue, Zi-Li
name: Xiao, Cheng-Jian
name: Chen, Dian-Yong
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Inspired by the recent observations of $T_{c\bar{s}0}^{0/++}$ in the the processes $B^0\to\bar{D}^0 D_s^+ π^-$ and $B^+\to D^- D_s^+ π^+$ by LHCb Collaboration, we investigate the decay properties of the $T_{c\bar{s}0}^{0}$ in a $D^{*}K^{*}$ molecule scenario, and the widths of $T_{c\bar{s}0}^{0}\to D^{0}K^{0}$, $D_{s}^{+}π^{-}$, $D_{s}^{*+}ρ^{-}$, $D_{s1}^{(\prime)+}π^{-}$, and $D^{*0}(Dπ)^{0}$ are estimated. Our estimations indicate that the width of $T_{c\bar{s}0}^{0} \to D_s^+ π^-$ is sizable to be observed and the dominant decay mode of $T_{c\bar{s}0}^{0}$ is $D^0K^0$. Considering the isospin symmetry, we proposed to search $T_{c\bar{s}0}(2900)^{++}$ in the $D^+ K^+$ invariant mass distributions of the process $B^+ \to D^+ D^- K^+$, where some preliminary experimental hints have been observed by LHCb Collaboration.
description: 8 pages, 6 figures and 1 table
Monitoring der sozial-emotionalen Situation von Grundschülerinnen und Grundschülern - Ist der SDQ ein geeignetes Verfahren?
Creators: name: Voss, S.
name: Gebhardt, Markus
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: SDQ, total difficulties score, monitoring, course measurement, behavioral development, Rasch model
subject: 370 Erziehung, Schul- und Bildungswesen

description: Der Strength and Difficulties Questionnaire (SDQ) ist ein in Forschung und Praxis etabliertes Screeninginstrument zur Diagnostik von Verhaltensstörungen. Im vorliegenden Artikel wird neben der statusdiagnostischen Eignung der Lehrkraftversion des SDQ über die vier Jahre der Grundschule zu je einem Messzeitpunkt hinweg die Einsetzbarkeit des Verfahrens als Instrument zur Verlaufsmessung geprüft. Um die Skalierung über die vier Messzeitpunkte zu untersuchen, wird die Problemwertskala des SDQ mittels des Raschmodells an einer Schuljahreskohorte einer deutschen Kleinstadt im Längsschnitt analysiert. Die Ergebnisse zeigen, dass der SDQ Gesamtproblemwert mit wenigen Ausnahmen messinvariant über die Zeit ist. Im Raschmodell über vier Messzeitpunkte weicht ein Item vom eindimensionalen Modell ab und wird für weitere Berechnungen entfernt. Anhand von Mehrebenenregressionen erkennt man, dass die Personenwerte der Grundschulkinder im Gesamtproblemwert über die Schuljahre leicht ansteigen. Eine Weiterentwicklung des SDQ Richtung eines Instrumentes zur Verlaufsmessung ist möglich, hierzu sollten weitere Items im schwierigen und leichten Bereich konstruiert werden. The Strength and Difficulties Questionnaire (SDQ) is an established screening tool in research and practice for the purpose of diagnosing behavioral disorders. In this article the teacher version of the SDQ is analyzed in light of its status diagnostic suitability. Longitudinal data of a school year cohort from a small German town was collected to investigate if the total difficulties score over time meets the requirements of the Rasch model and thus if it’s appropriate for progress monitoring purposes too. The results support measurement equivalence of the SDQ total difficulties score over time but with few exceptions. Only one item failed the criteria of the one-dimensional Rasch model and had to be removed from further calculations. Multilevel regressions indicate a slight increase of the total difficulties score over the school years. A further development of the SDQ towards a progress monitoring measurement is possible. For this purpose, additional items should be constructed to reach a better targeting of the instrument.
Modelling frequency-dependent tidal deformability for environmental black-hole mergers
Creators: name: De Luca, Valerio
name: Maselli, Andrea
name: Pani, Paolo
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Motivated by events in which black holes can lose their environment due to tidal interactions in a binary system, we develop a waveform model in which the tidal deformability interpolates between a finite value (dressed black hole) at relatively low frequency and a zero value (naked black hole) at high frequency. We then apply this model to the example case of a black hole dressed with an ultralight scalar field and investigate the detectability of the tidal Love number with the Einstein Telescope. We show that the parameters of the tidal deformability model could be measured with high accuracy, providing a useful tool to understand dynamical environmental effects taking place during the inspiral of a binary system.
description: 7 pages, 3 figures. v2: matching published version
Spatial effect on stochastic dynamics of bistable evolutionary games
Creators: name: So, Kohaku H. Z.
name: Ohtsuki, Hisashi
name: Kato, Takeo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: We consider the lifetimes of metastable states in bistable evolutionary games (coordination games), and examine how they are affected by spatial structure. A semiclassical approximation based on a path integral method is applied to stochastic evolutionary game dynamics with and without spatial structure, and the lifetimes of the metastable states are evaluated. It is shown that the population dependence of the lifetimes is qualitatively different in these two models. Our result indicates that spatial structure can accelerate the transitions between metastable states.
Model independent bounds for the number of $e$-folds during the evolution of the universe
Creators: name: German, G.
name: Quaglia, R. Gonzalez
name: Colorado, A. M. Moran
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a simple procedure to obtain universal bounds for quantities of cosmological interest, such as the number of $e$-folds during inflation, reheating, and radiation, as well as the reheating temperature. The main assumption is to represent each of the various epochs of evolution of the universe as being due to a single substance changing instantaneously into the next, describing a new era of evolution of the universe. This assumption, commonly used to obtain solutions of the Friedmann equations for simple cosmological models, is implemented here to find model-independent bounds on cosmological quantities of interest. In particular, we find that the bound $N_k\approx 56$ for $-\frac{1}{3} < ω_{re} < \frac{1}{3}$ is very robust as an upper bound on the number of $e$-folds during inflation and also as a lower bound when $ω_{re} > \frac{1}{3}$, where $ω_{re}$ is the effective equation of state parameter during reheating. These are model-independent results that any single-field model of inflation should satisfy. As an example, we illustrate the two approaches with the basic $α$ attractor model and show how they complement each other.
description: 17 pages, 3 figures, 3 tables. Accepted for publication in JCAP
Lepton Flavor Violation in the Standard Model with general Dimension-Six Operators
Creators: name: Crivellin, Andreas
name: Najjari, Saereh
name: Rosiek, Janusz
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study lepton flavor observables in the Standard Model (SM) extended with all dimension-$6$ operators which are invariant under the SM gauge group. We calculate the complete one-loop predictions to the radiative lepton decays $μ\to eγ$, $τ\to μγ$ and $τ\to eγ$ as well as to the closely related anomalous magnetic moments and electric dipole moments of charged leptons, taking into account all dimension-$6$ operators which can generate lepton flavor violation. Also the 3-body flavor violating charged lepton decays $τ^\pm \to μ^\pm μ^+ μ^-$, $τ^\pm\to e^\pm e^+ e^- $, $τ^\pm \to e^\pm μ^+ μ^- $, $τ^\pm \to μ^\pm e^+ e^- $, $τ^\pm \to e^\mp μ^\pm μ^\pm$, $τ^\pm \to μ^\mp e^\pm e^\pm $ and $μ^\pm \to e^\pm e^+ e^-$ and the $Z^0$ decays $Z^0\to\ell_i^+\ell_j^-$ are considered, taking into account all tree-level contributions.
description: 33 pages, 7 figures, misprints corrected, references added
Landau level spectrum and magneto-optical conductivity in tilted Weyl semimetal
Creators: name: Liu, Pu
name: Cui, Chaoxi
name: Li, Xiao-Ping
name: Yu, Zhi-Ming
name: Yao, Yugui
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a systematic investigation of the magnetoresponses of the Weyl points (WPs) with a topological charge of n = 2, 3 and 4, and with both linear and quadratic energy tilt. The linear tilt always tends to squeeze the Landau levels (LLs) of both conduction and valence bands of all the WPs, and eventually leads to LL collapse in the type-II phase. However, the quadratic energy tilt has more complex influences on the LLs of the unconventional WPs. For charge-n (n = 2, 4) WP, the influence of the quadratic tilt on the LLs of conduction and valence bands are opposite, i.e. if the LLs of conduction (valence) bands are squeezed, then that of the valence (conduction) bands are broadened, and the squeezed LL spectrum will be collapsed in type-III phase. But, the LL collapse generally can not be found in the type-III charge-3 WP. Moreover, for charge-n (n = 2, 3) WP, the quadratic tilt breaks the degeneracy of the chiral LLs regardless of the direction of the magnetic field, leading to additional optical transitions and magneto-optical conductivity peaks at low frequencies. Interestingly, the four chiral LLs in charge-4 WP are always not degenerate. Hence, there inevitably exist magneto-optical conductivity peaks at low frequencies for charge-4 WP. Since the density of state of the LL spectrum is very large, one can expect that the low-frequency magneto-optical responses in unconventional WPs would be significant and may be used for developing efficient terahertz photodetectors.
MOA-2013-BLG-220Lb: Massive Planetary Companion to Galactic-Disk Host
Creators: name: Yee, J. C.
name: Han, C.
name: Gould, A.
name: Skowron, J.
name: Bond, I. A.
name: Udalski, A.
name: Hundertmark, M.
name: Monard, L. A. G.
name: Porritt, I.
name: Nelson, P.
name: Bozza, V.
name: Albrow, M. D.
name: Choi, J. -Y.
name: Christie, G. W.
name: DePoy, D. L.
name: Gaudi, B. S.
name: Hwang, K. -H.
name: Jung, Y. K.
name: Lee, C. -U.
name: McCormick, J.
name: Natusch, T.
name: Ngan, H.
name: Park, H.
name: Pogge, R. W.
name: Shin, I. -G.
name: Tan, T. -G.
name: Abe, F.
name: Bennett, D. P.
name: Botzler, C. S.
name: Freeman, M.
name: Fukui, A.
name: Fukunaga, D.
name: Itow, Y.
name: Koshimoto, N.
name: Larsen, P.
name: Ling, C. H.
name: Masuda, K.
name: Matsubara, Y.
name: Muraki, Y.
name: Namba, S.
name: Ohnishi, K.
name: Philpott, L.
name: Rattenbury, N. J.
name: Saito, To.
name: Sullivan, D. J.
name: Sumi, T.
name: Sweatman, W. L.
name: Suzuki, D.
name: Tristram, P. J.
name: Tsurumi, N.
name: Wada, K.
name: Yamai, N.
name: Yock, P. C. M.
name: Yonehara, A.
name: Szymański, M. K.
name: Ulaczyk, K.
name: Kozłowski, S.
name: Poleski, R.
name: Wyrzykowski, Ł.
name: Kubiak, M.
name: Pietrukowicz, P.
name: Pietrzyński, G.
name: Soszyński, I.
name: Bramich, D. M.
name: Browne, P.
name: Jaimes, R. Figuera
name: Horne, K.
name: Ipatov, S.
name: Kains, N.
name: Snodgrass, C.
name: Steele, I. A.
name: Street, R.
name: Tsapras, Y.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report the discovery of MOA-2013-BLG-220Lb, which has a super-Jupiter mass ratio $q=3.01\pm 0.02\times 10^{-3}$ relative to its host. The proper motion, $μ=12.5\pm 1\, {\rm mas}\,{\rm yr}^{-1}$, is one of the highest for microlensing planets yet discovered, implying that it will be possible to separately resolve the host within $\sim 7$ years. Two separate lines of evidence imply that the planet and host are in the Galactic disk. The planet could have been detected and characterized purely with follow-up data, which has important implications for microlensing surveys, both current and into the LSST era.
description: 2 tables, 2 figures
The Thousand-Pulsar-Array programme on MeerKAT XI: Application of the rotating vector model
Creators: name: Johnston, Simon
name: Kramer, Michael
name: Karastergiou, Aris
name: Keith, Mike
name: Oswald, Lucy
name: Parthasarathy, Aditya
name: Weltevrede, Patrick
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In spite of the rich phenomenology of the polarization properties of radio pulsars, the rotating vector model (RVM) created 50 years ago remains the best method to determine the beam geometry of a pulsar. We apply the RVM to a sample of 854 radio pulsars observed with the MeerKAT telescope in order to draw conclusions about the population of pulsars as a whole. The main results are that (i) the geometrical interpretation of the position angle traverse is valid in the majority of the population, (ii) the pulsars for which the RVM fails tend to have a high fraction of circular polarization compared to linear polarization, (iii) emission heights obtained through both geometrical and relativistic methods show that the majority of pulsars must have emission heights less than 1000~km independent of spin period, (iv) orthogonal mode jumps are seen in the position angle traverse in about one third of the population. All these results are weakly dependent on the pulsar spin-down energy.
description: accepted by MNRAS
String theoretic QCD axions in the light of PLANCK and BICEP2
Creators: name: Choi, Kiwoon
name: Jeong, Kwang Sik
name: Seo, Min-Seok
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The QCD axion solving the strong CP problem may originate from antisymmetric tensor gauge fields in compactified string theory, with a decay constant around the GUT scale. Such possibility appears to be ruled out now by the detection of tensor modes by BICEP2 and the PLANCK constraints on isocurvature density perturbations. A more interesting and still viable possibility is that the string theoretic QCD axion is charged under an anomalous U(1)_A gauge symmetry. In such case, the axion decay constant can be much lower than the GUT scale if moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and U(1)_A-charged matter fields get a vacuum value far below the GUT scale due to a tachyonic SUSY breaking scalar mass. We examine the symmetry breaking pattern of such models during the inflationary epoch with the Hubble expansion rate 10^{14} GeV, and identify the range of the QCD axion decay constant, as well as the corresponding relic axion abundance, consistent with known cosmological constraints. In addition to the case that the PQ symmetry is restored during inflation, there are other viable scenarios, including that the PQ symmetry is broken during inflation at high scales around 10^{16}-10^{17} GeV due to a large Hubble-induced tachyonic scalar mass from the U(1)_A D-term, while the present axion scale is in the range 10^{9}-5\times 10^{13} GeV, where the present value larger than 10^{12} GeV requires a fine-tuning of the axion misalignment angle. We also discuss the implications of our results for the size of SUSY breaking soft masses.
description: 29 pages, 1 figure; v3: analysis updated including the full anharmonic effects, references added, version accepted for publication in JHEP
Loschmidt echo and dynamical fidelity in periodically driven quantum systems
Creators: name: Sharma, Shraddha
name: Russomanno, Angelo
name: Santoro, Giuseppe E.
name: Dutta, Amit
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the dynamical fidelity $\mathcal{F} (t)$ and the Loschmidt echo $\mathcal{L} (t)$, following a periodic driving of the transverse magnetic field of a quantum Ising chain (back and forth across the quantum critical point) by calculating the overlap between the initial ground state and the state reached after $n$ periods $τ$. We show that $\log{\mathcal{F}}(nτ)/L$ (the logarithm of the fidelity per-site) reaches a steady value in the asymptotic limit $n\to \infty$, and we derive an exact analytical expression for this quantity. Remarkably, the steady state value of $[\log{\mathcal{F}}(nτ\to \infty)]/L$ shows memory of non-trivial phase information which is instead hidden in the case of thermodynamic quantities; this conclusion, moreover, is not restricted to 1-dimensional models.
description: 5 pages, 4 figures, accepted for publication in EPL
A self-locking Rydberg atom electric field sensor
Creators: name: Fancher, C. T.
name: Nicolich, K.
name: Backes, K.
name: Malvania, N.
name: Cox, K.
name: Meyer, D. H.
name: Kunz, P. D.
name: Hill, J. C.
name: Holland, W.
name: Marlow, B. L. Schmittberger
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A crucial step towards enabling real-world applications for quantum sensing devices such as Rydberg atom electric field sensors is reducing their size, weight, power, and cost (SWaP-C) requirements without significantly reducing performance. Laser frequency stabilization is a key part of many quantum sensing devices and, when used for exciting non-ground state atomic transitions, is currently limited to techniques that require either large SWaP-C optical cavities and electronics or use significant optical power solely for frequency stabilization. Here we describe a laser frequency stabilization technique for exciting non-ground state atomic transitions that solves these challenges and requires only a small amount of additional electronics. We describe the operation, capabilities, and limitations of this frequency stabilization technique and quantitatively characterize measure its performance. We show experimentally that Rydberg electric field sensors using this technique are capable of data collection while sacrificing only 0.1% of available bandwidth for frequency stabilization of noise up to 900 Hz.
description: 6 pages, 5 figures
Finite-size scaling at first-order quantum transitions
Creators: name: Campostrini, Massimo
name: Nespolo, Jacopo
name: Pelissetto, Andrea
name: Vicari, Ettore
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study finite-size effects at first-order quantum transitions (FOQTs). We show that the low-energy properties show a finite-size scaling (FSS) behavior, the relevant scaling variable being the ratio of the energy associated with the perturbation driving the transition and the finite-size energy gap at the FOQT point. The size dependence of the scaling variable is therefore essentially determined by the size dependence of the gap at the transition, which in turn depends on the boundary conditions. Our results have broad validity and, in particular, apply to any FOQT characterized by the degeneracy and crossing of the two lowest-energy states in the infinite-volume limit. In this case, a phenomenological two-level theory provides exact expressions for the scaling functions. Numerical results for the quantum Ising chain in transverse and parallel magnetic fields support the FSS ansatzes.
description: 5 pages
Modelling particle collisions in moderately dense curtain impacted by an incident shock wave
Creators: name: Zhang, Pikai
name: Zhang, Huangwei
name: Zhang, Yun Feng
name: Li, Shangpeng
name: Meng, Qingyang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The interactions between an incident shock and moderately dense particle curtain are simulated with the Eulerian-Lagrangian method. A customized solver based on OpenFOAM is extended with an improved drag model and collision model, and then validated against two benchmark experiments. In this work, parametric studies are performed considering different particle sizes, volume fractions, and curtain thicknesses. It is found that smaller particle size and larger volume fractions lead to stronger reflected shock and weaker transmitted shock. Different expansion stages of the curtain fronts are also studied in detail. Attention is paid to the particle collision effects on the curtain evolution behaviours. According to our results, for the mono-dispersed particle curtain, the collision effects on curtain front behaviors are small, even when the initial particle volume fraction is as high as 20%. This is due to the positive velocity gradient across the curtain after the shock wave passage, leading to faster motion of downstream particles than the upstream ones and hence no collision occurs. For the bi-dispersed particle curtain, the collision effects become important in the mixing region of different-size particles. Collisions decelerate small particles while accelerate large ones and cause velocity scattering. Moreover, increasing the bi-dispersed curtain thickness leads to multiple collision force peaks due to the local particle accumulations, which is the result of the delayed separation of different particle groups. Our results indicate that the collision model may be unnecessary to predict curtain fronts in mono-dispersed particles, but in bi-dispersed particles, the collision effects are important and therefore must be modelled.
Variational Monte Carlo Method for Electron-Phonon Coupled Systems
Creators: name: Ohgoe, Takahiro
name: Imada, Masatoshi
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We develop a variational Monte Carlo (VMC) method for electron-phonon coupled systems. The VMC method has been extensively used for investigating strongly correlated electrons over the last decades. However, its applications to electron-phonon coupled systems have been severely restricted because of its large Hilbert space. Here, we propose a variational wave function with a large number of variational parameters which is suitable and tractable for systems with electron-phonon coupling. In the proposed wave function, we implement an unexplored electron-phonon correlation factor which takes into account the effect of the entanglement between electrons and phonons. The method is applied to systems with diagonal electron-phonon interactions, i.e. interactions between charge densities and lattice displacements (phonons). As benchmarks, we compare VMC results with previous results obtained by the exact diagonalization, the Green function Monte Carlo and the density matrix renormalization group for the Holstein and Holstein-Hubbard model. From these benchmarks, we show that the present method offers an efficient way to treat strongly coupled electron-phonon systems.
Three-dimensional solar active region magnetohydrostatic models and their stability using Euler potentials
Creators: name: Terradas, Jaume
name: Neukirch, Thomas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Active regions (ARs) are typical magnetic structures found in the solar atmosphere. We calculate several magnetohydrostatic (MHS) equilibrium models that include the effect of a finite plasma-$β$ and gravity and that are representative of these structures in three dimensions. The construction of the models is based on the use of two Euler potentials, $α$ and $β$, that represent the magnetic field as ${\bf B}=\nabla α\times \nabla β$. The ideal MHS nonlinear partial differential equations are solved numerically using finite elements in a fixed 3D rectangular domain. The boundary conditions are initially chosen to correspond to a potential magnetic field (current-free) with known analytical expressions for the corresponding Euler potentials. The distinctive feature is that we incorporate the effect of shear by progressively deforming the initial potential magnetic field. This procedure is quite generic and allows us to generate a vast variety of MHS models. The thermal structure of the ARs is incorporated through the dependence of gas pressure and temperature on the Euler potentials. Using this method we achieve the characteristic hot and over-dense plasma found in ARs, but we demonstrate that the method can also be applied to study configurations with open magnetic field lines. Furthermore, we investigate basic topologies that include neutral lines. Our focus is on the force balance of the structures and we do not consider the energy balance in the constructed models. In addition, we address the difficult question of the stability of the calculated 3D models. We find that if the plasma is convectively stable, then the system is not prone in general to develop magnetic Rayleigh-Taylor instabilities.
description: Accepted for publication in A&A
On the large argument asymptotics of the Lommel function via Stieltjes transforms
Creators: name: Nemes, Gergő
Publisher: name: arXiv
Year: 2014
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 41A60, 30E15, 34M40

description: The aim of this paper is to investigate in detail the known large argument asymptotic series of the Lommel function by Stieltjes transform representations. We obtain a number of properties of this asymptotic expansion, including explicit and realistic error bounds, exponentially improved asymptotic expansions, and the smooth transition of the Stokes discontinuities. An interesting consequence related to the large argument asymptotic series of the Struve function is also proved.
description: 20 pages
Spin Excitation in Coupled Honeycomb Lattice Ni$_2$InSbO$_6$
Creators: name: Liu, Zheyuan
name: Arima, Taka-hisa
name: Itoh, Shinichi
name: Asai, Shinichiro
name: Masuda, Takatsugu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We performed an inelastic neutron scattering experiment on a polycrystalline sample of a helimagnet Ni$_2$InSbO$_6$ to construct the spin Hamiltonian. Well-defined spin-wave excitation with a band energy of 20 meV was observed below $T_{N} = 76$ K. Using the linear spin-wave theory, the spectrum was reasonably reproduced with honeycomb spin layers coupled along the stacking axis (the $c$ axis). The proposed spin model reproduces the soliton lattice induced by a magnetic field applied perpendicular to the $c$ axis.
description: 8 pages, 5 figures
Non-local gravity and dark energy
Creators: name: Maggiore, Michele
name: Mancarella, Michele
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We discuss a nonlocal modification of gravity obtained adding a term $m^2 R\,\Box^{-2}R$ to the Einstein-Hilbert action. We find that the mass parameter $m$ only affects the non-radiative sector of the theory, while the graviton remains massless, there is no propagating ghost-like degree of freedom, no vDVZ discontinuity, and no Vainshtein radius below which the theory becomes strongly coupled. For $m={\cal O}(H_0)$ the theory therefore recovers all successes of GR at solar system and lab scales, and only deviates from it at cosmological scales. We examine the cosmological consequences of the model and we find that it automatically generates a dynamical dark energy and a self-accelerating evolution. After fixing our only free parameter $m$ so to reproduce the observed value of the dark energy density today, we get a pure prediction for the dark energy equation of state, $w_ {\rm DE}\simeq-1.14$. This value is consistent with the existing data, and could also resolve the possible tension between the Planck data and local measurements of the Hubble parameter.
description: 7 pages, 3 figures; v2: the version accepted in PRD
Domain Adaptation of Transformer-Based Models using Unlabeled Data for Relevance and Polarity Classification of German Customer Feedback
Creators: name: Idrissi-Yaghir, Ahmad
name: Schäfer, Henning
name: Bauer, Nadja
name: Friedrich, Christoph M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Understanding customer feedback is becoming a necessity for companies to identify problems and improve their products and services. Text classification and sentiment analysis can play a major role in analyzing this data by using a variety of machine and deep learning approaches. In this work, different transformer-based models are utilized to explore how efficient these models are when working with a German customer feedback dataset. In addition, these pre-trained models are further analyzed to determine if adapting them to a specific domain using unlabeled data can yield better results than off-the-shelf pre-trained models. To evaluate the models, two downstream tasks from the GermEval 2017 are considered. The experimental results show that transformer-based models can reach significant improvements compared to a fastText baseline and outperform the published scores and previous models. For the subtask Relevance Classification, the best models achieve a micro-averaged $F1$-Score of 96.1 % on the first test set and 95.9 % on the second one, and a score of 85.1 % and 85.3 % for the subtask Polarity Classification.
description: Complete
Azimuthal asymmetries of muon pair production in ultraperipheral heavy ion collisions
Creators: name: Shao, Ding Yu
name: Zhang, Cheng
name: Zhou, Jian
name: Zhou, Yajin
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper we study azimuthal asymmetries of the muon pair production in ultraperipheral heavy ion collisions within the joint impact parameter and transverse momentum dependent framework. The final state QED radiation effects are resummed to all orders in perturbation theory, where the complete muon mass corrections are also taken into account. We further make numerical estimations for azimuthal asymmetries in the different kinematic regions accessible at RHIC and LHC with the derived resummation formula. We find that the lepton mass effects can give sizable corrections to the asymmetries at relatively large pair transverse momentum at RHIC energy.
description: 7 pages, 6 figures, v2, matches the version published in PRD
Studies of Azimuthal Modulations in Two Hadron Fragmentation of a Transversely Polarised Quark
Creators: name: Matevosyan, Hrayr H.
name: Kotzinian, Aram
name: Thomas, Anthony W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the azimuthal modulations of dihadron fragmentation functions (DiFFs) of a transversely polarised quark using an NJL-jet based model that incorporates the Collins effect for single hadron emission. The DiFFs are extracted as Monte Carlo (MC) averages of corresponding multiplicities using their probabilistic interpretation. To simplify the model and highlight the possible mechanisms that create this modulation, we choose the elementary Collins function to be proportional to the elementary unpolarised fragmentation and a constant probability ($P_{SF}$) for the quark to flip its spin after a single hadron emission. Moreover, as a leading order calculation, only one of the produced hadrons in the decay chain of the quark is produced with elementary Collins modulation. We calculate the dependence of the polarised DiFFs on various angles such as the azimuthal angle of the single hadron and the angle of the two hadron production plane $φ_R$ for several values of $P_{SF}$. We observe that the polarised DiFFs for oppositely charged pion pairs exhibit a $\sin(φ_R)$ modulation. This effect is induced purely via the elementary Collins effect and persists even when the quark completely depolarises after a single hadron emission ($P_{SF}=0.5$). Moreover, similar sine modulations are present in the distribution of pion pairs with respect to the azimuthal angle of their total transverse momentum, $φ_T$.
description: 10 pages, 12 figures - small updates and added references, to comply with the version to be published in PLB
Entanglement Typicality
Creators: name: Dahlsten, Oscar C. O.
name: Lupo, Cosmo
name: Mancini, Stefano
name: Serafini, Alessio
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We provide a summary of both seminal and recent results on typical entanglement. By typical values of entanglement, we refer here to values of entanglement quantifiers that (given a reasonable measure on the manifold of states) appear with arbitrarily high probability for quantum systems of sufficiently high dimensionality. We work within the Haar measure framework for discrete quantum variables, where we report on results concerning the average von Neumann and linear entropies as well as arguments implying the typicality of such values in the asymptotic limit. We then proceed to discuss the generation of typical quantum states with random circuitry. Different phases of entanglement, and the connection between typical entanglement and thermodynamics are discussed. We also cover approaches to measures on the non-compact set of Gaussian states of continuous variable quantum systems.
description: Review paper with two quotes and minimalist figures
A non-squeezing theorem for convex symplectic images of the Hilbert ball
Creators: name: Abbondandolo, Alberto
name: Majer, Pietro
Publisher: name: arXiv
Year: 2014
Subjects: subject: Symplectic Geometry (math.SG)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We prove that the non-squeezing theorem of Gromov holds for symplectomorphisms on an infinite-dimensional symplectic Hilbert space, under the assumption that the image of the ball is convex. The proof is based on the construction by duality methods of a symplectic capacity for bounded convex neighbourhoods of the origin. We also discuss some examples of symplectomorphisms on infinite-dimensional spaces exhibiting behaviours which would be impossible in finite dimensions.
description: Added application to the nonlinear Schr\"odinger equation
An ionized outflow in Orion-KL source I?
Creators: name: Wright, Melvyn
name: Hirota, Tomoya
name: Forbrich, Jan
name: Plambeck, Richard
name: Bally, John
name: Goddi, Ciriaco
name: Ginsburg, Adam
name: McGuire, Brett A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present images at 6 and 14 GHz of Source I in Orion-KL. At higher frequencies, from 43 to 340 GHz, images of this source are dominated by thermal emission from dust in a 100 AU diameter circumstellar disk, but at 6 and 14 GHz the emission is elongated along the minor axis of the disk, aligned with the SiO bipolar outflow from the central object. Gaussian fits to the 6, 14, 43, and 99 GHz images find a component along the disk minor axis whose flux and length vary with frequency consistent with free-free emission from an ionized outflow. The data favor a broad outflow from a disk wind, rather than a narrow ionized jet. Source I was undetected in higher resolution 5 GHz e-MERLIN observations obtained in 2021. The 5-6 GHz structure of SrcI may be resolved out by the high sidelobe structure of the e-MERLIN synthesized beam, or be time variable.
description: Accepted in ApJ
Towards learning Lattice Boltzmann collision operators
Creators: name: Corbetta, Alessandro
name: Gabbana, Alessandro
name: Gyrya, Vitaliy
name: Livescu, Daniel
name: Prins, Joost
name: Toschi, Federico
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: In this work we explore the possibility of learning from data collision operators for the Lattice Boltzmann Method using a deep learning approach. We compare a hierarchy of designs of the neural network (NN) collision operator and evaluate the performance of the resulting LBM method in reproducing time dynamics of several canonical flows. In the current study, as a first attempt to address the learning problem, the data was generated by a single relaxation time BGK operator. We demonstrate that vanilla NN architecture has very limited accuracy. On the other hand, by embedding physical properties, such as conservation laws and symmetries, it is possible to dramatically increase the accuracy by several orders of magnitude and correctly reproduce the short and long time dynamics of standard fluid flows.
Cross section ratio and angular distributions of the reaction p + d -> 3He + eta at 48.8 MeV and 59.8 MeV excess energy
Creators: name: Adlarson, P.
name: Augustyniak, W.
name: Bardan, W.
name: Bashkanov, M.
name: Bergmann, F. S.
name: Berłowski, M.
name: Bhatt, H.
name: Büscher, M.
name: Calén, H.
name: Ciepał, I.
name: Clement, H.
name: Coderre, D.
name: Czerwiński, E.
name: Demmich, K.
name: Doroshkevich, E.
name: Engels, R.
name: Erven, A.
name: Erven, W.
name: Eyrich, W.
name: Fedorets, P.
name: Föhl, K.
name: Fransson, K.
name: Goldenbaum, F.
name: Goslawski, P.
name: Goswami, A.
name: Grigoryev, K.
name: Gullström, C. -O.
name: Hauenstein, F.
name: Heijkenskjöld, L.
name: Hejny, V.
name: Hodana, M.
name: Höistad, B.
name: Hüsken, N.
name: Jany, A.
name: Jany, B. R.
name: Jarczyk, L.
name: Johansson, T.
name: Kamys, B.
name: Kemmerling, G.
name: Khan, F. A.
name: Khoukaz, A.
name: Kirillov, D. A.
name: Kistryn, S.
name: Kłos, B.
name: Kleines, H.
name: Krapp, M.
name: Krzemień, W.
name: Kulessa, P.
name: Kupść, A.
name: Lalwani, K.
name: Lersch, D.
name: Lorentz, B.
name: Magiera, A.
name: Maier, R.
name: Marciniewski, P.
name: Mariański, B.
name: Mikirtychiants, M.
name: Morsch, H. --P.
name: Moskal, P.
name: Ohm, H.
name: Ozerianska, I.
name: Passfeld, A.
name: del Rio, E. Perez
name: Piskunov, N. M.
name: Podkopał, P.
name: Prasuhn, D.
name: Pricking, A.
name: Pszczel, D.
name: Pysz, K.
name: Pyszniak, A.
name: Redmer, C. F.
name: Ritman, J.
name: Roy, A.
name: Rudy, Z.
name: Sawant, S.
name: Schadmand, S.
name: Sefzick, T.
name: Serdyuk, V.
name: Siudak, R.
name: Skorodko, T.
name: Skurzok, M.
name: Smyrski, J.
name: Sopov, V.
name: Stassen, R.
name: Stepaniak, J.
name: Stephan, E.
name: Sterzenbach, G.
name: Stockhorst, H.
name: Ströher, H.
name: Szczurek, A.
name: Täschner, A.
name: Trzciński, A.
name: Varma, R.
name: Wagner, G. J.
name: Węglorz, W.
name: Wolke, M.
name: Wrońska, A.
name: Wüstner, P.
name: Wurm, P.
name: Yamamoto, A.
name: Yurev, L.
name: Zabierowski, J.
name: Zieliński, M. J.
name: Zink, A.
name: Złomańczuk, J.
name: Żuprański, P.
name: Żurek, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present new data for angular distributions and on the cross section ratio of the p + d -> 3He + eta reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Jülich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.
description: 9 pages, 9 figures
Impact of Carbon Support Meso‐Porosity on Mass Transport and Performance of PEMFC Cathode Catalyst Layers
Creators: name: Ott, Sebastian
name: Bauer, Andreas
name: Du, Fengmin
name: Dao, Tuan Anh
name: Klingenhof, Malte
name: Orfanidi, Alin
name: Strasser, Peter
Publisher: name: Technische Universität Berlin
Year: 2021
Subjects: subject: 540 Chemie und zugeordnete Wissenschaften
subject: oxygen reduction reaction
subject: fuel cell
subject: mass transport
subject: porosity
subject: catalyst layer

description: The analysis of the impact of the cathode catalyst layer pore structure on the membrane electrode assembly (MEA) cell performance of a PEMFC is presented. In this study, a pristine CMK‐3 catalyst carbon support material with well‐defined pore structure in the 3–6 nm range together with two nitrogen‐doped variants is analyzed against a commercial carbon black to achieve a better understanding of catalyst layer porosity‐performance relations. We used chemically N‐doped CMK‐3 catalyst to learn more about the effect of N‐doped porous catalyst supports on the concomitant transport properties and PEMFC cell performance. Chemical treatment using cyanamide was conducted to introduce a variety of N‐functionalities. A detailed in‐situ electrochemical investigation was combined with N2‐physisorption analysis. Based on their structural properties, the mesopore fractions and pore openings display a major role for reducing oxygen transport resistance and enhance Pt accessibility. We find that hierarchically ordered mesoporosity is superior to disordered porosity with prevalent micropore character: Analysis including adsorption electrochemical active surface area (ECSA), Pt‐accessibility, ionomer coverage, pore geometry, proton resistivity and transport loss we conclude the importance of a well‐defined mesoporous structure for its cell performance.
Semi-classical analysis of the inner product of Bethe states
Creators: name: Bettelheim, Eldad
name: Kostov, Ivan
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the inner product of two Bethe states, one of which is taken on-shell, in an inhomogeneous XXX chain in the Sutherland limit, where the number of magnons is comparable with the length L of the chain and the magnon rapidities arrange in a small number of macroscopically large Bethe strings. The leading order in the large L limit is known to be expressed through a contour integral of a dilogarithm. Here we derive the subleading term. Our analysis is based on a new contour-integral representation of the inner product in terms of a Fredholm determinant. We give two derivations of the sub-leading term. Besides a direct derivation by solving a Riemann-Hilbert problem, we give a less rigorous, but more intuitive derivation by field-theoretical methods. For that we represent the Fredholm determinant as an expectation value in a Fock space of chiral fermions and then bosonize. We construct a collective field for the bosonized theory, the short wave-length part of which may be evaluated exactly, while the long wave-length part is amenable to a $1/L$ expansion. Our treatment thus results in a systematic 1/L expansion of structure factors within the Sutherland limit.
description: 22 pages, 0 figures