cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Red Giants' Toy Story
Creators: name: Bertolami, Marcelo M. Miller
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In spite of the spectacular progress accomplished by stellar evolution theory some simple questions remain unanswered. One of these questions is ``Why do stars become Red Giants?''. Here we present a relatively simple analytical answer to this question. We validate our analysis by constructing a quantitative toy-model of a red giant and comparing its predictions to full stellar evolutionar models. We find that the envelope forces the value of $\nabla=d \ln T/d \ln P$ at, and above, the burning shell into a very narrow range of possible values. Together with the fact that the stellar material at the burning shell both provides and transports most of the stellar luminosity, this leads to tight relations between the thermodynamic variables at the burning shell and the mass and radius of the core -- $T_s(M_c,R_s)$, $P_s(M_c,R_s)$ and $ρ_s(M_c,R_s)$. When complemented by typical mass-radius relations of the helium cores, this implies that for all stellar masses the evolution of the core dictates the values of $T_s$, $P_s$ and $ρ_s$. We show that for all stellar masses evolution leads to an increase in the pressure and density contrasts between the shell and the core, forcing a huge expansion of the layers on top of the burning shell. Besides explaining why stars become red giants our analysis also offers a mathematical demonstration of the so-called shell homology relations, and provides simple quantitative answers to some properties of low-mass red giants.
description: Accepted for Publication in The Astrophysical Journal. Updated with minor corrections to match the accepted version after proofs. 27 Pages. 15 Figures. 5 appendixes
Quasi-two-dimensional Fermi surfaces of the antiferromagnet U$_2$RhIn$_8$ revealed by de Haas-van Alphen measurements
Creators: name: Aoki, D.
name: Homma, Y.
name: Harima, H.
name: Sheikin, I.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report temperature-dependent Hall effect and low-temperature de Haas-van Alphen (dHvA) effect measurements of the antiferromagnetic heavy-fermion compound U$_2$RhIn$_8$. Temperature dependence of the Hall resistivity suggests a considerable reduction of the carrier density in the antiferromagnetic phase. The observed angular dependence of the dHvA frequencies suggests the existence of three almost ideally two-dimensional Fermi surfaces one of which is quite large. The measured effective masses range from 2$m_0$ to 14$m_0$ for the field applied along the $c$ axis. Local density approximation band-structure calculations performed for the paramagnetic ground state reveal more three-dimensional Fermi surfaces than those observed in the experiment. On the other hand, Fermi surfaces obtained for the antiferromagnetic ground state by band folding are more two dimensional. These calculations account reasonably well for the experimental results assuming a slight modification of the calculated Fermi surfaces.
description: 10 pages, 9 figures, accepted for publication in Phys. Rev. B
Extremely bright GRB 160625B with multi-episodes emission: Evidences for long-term ejecta evolution
Creators: name: Lü, Hou-Jun
name: Lü, Jing
name: Zhong, Shu-Qing
name: Huang, Xiao-Li
name: Zhang, Hai-Ming
name: Lan, Lin
name: Xie, Wei
name: Lu, Rui-Jing
name: Liang, En-Wei
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: GRB 160625B is an extremely bright GRB with three distinct emission episodes. By analyzing its data observed with the GBM and LAT on board the {\em Fermi} mission, we find that a multi-color black body (mBB) model can be used to fit the spectra of initial short episode (Episode I) very well within the hypothesis of photosphere emission of a fireball model. The time-resolved spectra of its main episode (Episode II), which was detected with both GBM and LAT after a long quiet stage ($\sim 180$ seconds) of the initial episode, can be fitted with a model composing of an mBB component plus a cutoff power-law (CPL) component. This GRB was detected again in the GBM and LAT bands with a long extended emission (Episode III) after a quiet period of $\sim 300$ seconds. The spectrum of Episode III is adequately fitted with a CPL plus a single power-law models, and no mBB component is required. These features may imply that the emission of three episodes are dominated by distinct physics process, i.e., Episode I is possible from cocoon emission surrounding the relativistic jet, Episode II may be from photosphere emission and internal shock of relativistic jet, and Episode III is contributed by internal and external shocks of relativistic jet. On the other hand, both X-ray and optical afterglows are consistent with standard external shocks model.
description: 28 pages, 14 figures, and 2 Tables. Accepted for publication in ApJ
Toroidal flux loss due to flux emergence explains why solar cycles rise differently but decay in a similar way
Creators: name: Biswas, Akash
name: Karak, Bidya Binay
name: Cameron, Robert
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: A striking feature of the solar cycle is that at the beginning, sunspots appear around mid-latitudes, and over time the latitudes of emergences migrate towards the equator.The maximum level of activity (e.g., sunspot number) varies from cycle to cycle.For strong cycles, the activity begins early and at higher latitudes with wider sunspot distributions than for weak cycles. The activity and the width of sunspot belts increase rapidly and begin to decline when the belts are still at high latitudes. Surprisingly, it has been reported that in the late stages of the cycle the level of activity (sunspot number) as well as the widths and centers of the butterfly wings all have the same statistical properties independent of how strong the cycle was during its rise and maximum phases.We have modeled these features using a Babcock--Leighton type dynamo model and show that the flux loss through magnetic buoyancy is an essential nonlinearity in the solar dynamo.Our study shows that the nonlinearity is effective if the flux emergence becomes efficient at the mean-field strength of the order of $10^4$~G in the lower part of the convection zone.
description: Accepted in Phys.Rev.Lett. (PRL)
Stability of pentaquarks with a two- plus three-body chromoelectric interaction
Creators: name: Stancu, Fl.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the stability of pentaquarks within a schematic model based on SU(3) color symmetry, by taking into account algebraic arguments leading to a chromoelectric interaction containing two- and three-body parts. It has already been proven that such an interaction can influence the spectrum of ordinary baryons and the stability of tetraquarks and hexaquarks.
description: 11 pages, 1 figure, it matches the published version
Distributed control of vehicle strings under finite-time and safety specifications
Creators: name: Tallapragada, Pavankumar
name: Cortes, Jorge
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper studies an optimal control problem for a string of vehicles with safety requirements and finite-time specifications on the approach time to a target region. Our problem formulation is motivated by scenarios involving autonomous vehicles circulating on arterial roads with intelligent management at traffic intersections. We propose a provably correct distributed control algorithm that ensures that the vehicles satisfy the finite-time specifications under speed limits, acceleration saturation, and safety requirements. The safety specifications are such that collisions can be avoided even in cases of communication failure. We also discuss how the proposed distributed algorithm can be integrated with an intelligent intersection manager to provide information about the feasible approach times of the vehicle string and a guaranteed bound of its time of occupancy of the intersection. Our simulation study illustrates the algorithm and its properties regarding approach time, occupancy time, and fuel and time cost.
Axial gravity, massless fermions and trace anomalies
Creators: name: Bonora, L.
name: Cvitan, M.
name: Prester, P. Dominis
name: Pereira, A. Duarte
name: Giaccari, S.
name: Stemberga, T.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms { and using dimensional regularization}, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones.
description: 55 pages, comments added in section 2 and 5. Sections 6.4, 6.6, 7, 7.1, 7.2 and Appendices 5.3, 5.5 partially modified
Field Theory Approaches to Relativistic Hydrodynamics
Creators: name: Granese, Nahuel Mirón
name: Kandus, Alejandra
name: Calzetta, Esteban
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Just as non relativistic fluids, oftentimes we find relativistic fluids in situations where random fluctuations cannot be ignored, thermal and turbulent fluctuations being the most relevant examples. Because of the theory's inherent nonlinearity, fluctuations induce deep and complex changes in the dynamics of the system. The Martin-Siggia-Rose technique is a powerful tool that allows us to translate the original hydrodynamic problem into a quantum field theory one, thus taking advantage of the progress in the treatment of quantum fields out of equilibrium. To demonstrate this technique, we shall consider the thermal fluctuations of the spin two modes of a relativistic fluid, in a theory where hydrodynamics is derived by taking moments of the Boltzmann equation under the relaxation time approximation.
description: Accepted for publication in Entropy, Special Issue on Causal Relativistic Hydrodynamics for Viscous Fluids
On the underestimation of dust mass in protoplanetary disks: Effects of disk structure and dust properties
Creators: name: Liu, Yao
name: Linz, Hendrik
name: Fang, Min
name: Henning, Thomas
name: Wolf, Sebastian
name: Flock, Mario
name: Rosotti, Giovanni P.
name: Wang, Hongchi
name: Li, Dafa
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The total amount of dust grains in protoplanetary disks is one of the key properties that characterize the potential for planet formation. With (sub-)millimeter flux measurements, literature studies usually derive the dust mass using an analytic form under the assumption of optically thin emission, which may lead to substantial underestimation. In this work, we conduct a parameter study with the goal of investigating the effects of disk structure and dust properties on the underestimation through self-consistent radiative transfer models. Different dust models, scattering modes and approaches for dust settling are considered and compared. The influences of disk substructures, such as rings and crescents, on the mass derivation are investigated as well. The results indicate that the traditional analytic method can underestimate the mass by a factor of a few to hundreds, depending on the optical depth along the line of sight set mainly by the true dust mass, disk size and inclination. As an application, we perform a detailed radiative transfer modeling of the spectral energy distribution of DoAr 33, one of the observed DSHARP disks. When the DSHARP dust opacities are adopted, the most probable dust mass returned from the Bayesian analysis is roughly 7 times higher than the value given by the analytic calculation. Our study demonstrates that estimating disk dust masses from radiative transfer modeling is one solution for alleviating the problem of insufficient mass for planet formation raised in the ALMA era.
description: 16 pages, 9 figures, accepted for publication in A&A
Topologically nontrivial electronic states in CaSn$_{3}$
Creators: name: Gupta, Sunny
name: Juneja, Rinkle
name: Shinde, Ravindra
name: Singh, Abhishek K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Based on the first-principles calculations, we theoretically propose topologically non-trivial states in a recently experimentally discovered superconducting material CaSn$_3$. When the spin-orbit coupling (SOC) is ignored, the material is a host to three-dimensional topological nodal-line semimetal states. Drumhead like surface states protected by the coexistence of time-reversal and mirror symmetry emerge within the two-dimensional regions of the surface Brillouin zone connecting the nodal lines. When SOC is included, unexpectedly, each nodal line evolves into two Weyl nodes (W1, W2) in this centrosymmetric material. Berry curvature calculations show that these nodes occur in a pair and act as either a source or sink of Berry flux. The material also has unique surface states in the form of Fermi arcs, which unlike other known Weyl semimetal, form closed loops of surface states on the Fermi surface. Our theoretical realization of topologically non-trivial states in a superconducting material paves the way towards unraveling the interconnection between topological physics and superconductivity.
description: 6 pages, 3 figures
title: Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine
Creators: name: Franz, Gerhard
name: Lyckberg, Peter
name: Khomenko, Vladimir
name: Chernousenko, Vsevelod
name: Schulz, Hans-Martin
name: Mahlstedt, Nicolaj
name: Wirth, Richard
name: Glodny, Johannes
name: Gernert, Ulrich
name: Nissen, Jörg
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
The Volyn biota are a distinct and uncommon example of 3D-preservation of ~1.5 Ga old Precambrian fossils, recovered from cavities in pegmatites, which were the habitat for microorganisms in the deep biosphere. The Volyn pegmatite district is associated with the Paleoproterozoic Korosten Pluton, Ukraine. Breccias, formed during collapse of miarolitic cavities, contain decaying OM, which released NH4+, responsible for the late-stage formation of buddingtonite and tobelite-rich muscovite. The age of the fossils can therefore be restricted to the time between the pegmatite formation, at ~1.760 Ga (zircon U-Pb), and the breccia formation at ~ 1.5 Ga (muscovite Ar-Ar).

The organic matter (OM) is characterized as (oxy)kerite. Microanalytical investigations show that fossilization likely occurred during a hydrothermal, post-pegmatitic event, by silicification dominantly in the outermost 1-2 µm of the microfossils. The hydrothermal fluid, derived from the pegmatitic environment, was enriched in SiF4, Al, Ca, Na, K, Cl, and S. The OM shows O enrichment where N and S content is low, indicating simultaneous N and S loss during anaerobic oxidation. Mineralization with Al-silicates starts at the rim of the microfossils, continues in its outer parts into identifiable encrustations and intergrowths of clay minerals, feldspar, Ca-sulfate, Ca-phosphate, Fe-sulfide, and fluorite. As geological environment for growth and fossilization of the microorganisms we assume a geyser system, in which the essential biological components C, N, S, and P were derived from microorganisms at the surface. Fossilization was induced by magmatic SiF4-rich fluids.
Dynamical dark energy in light of the latest observations
Creators: name: Zhao, Gong-Bo
name: Raveri, Marco
name: Pogosian, Levon
name: Wang, Yuting
name: Crittenden, Robert G.
name: Handley, Will J.
name: Percival, Will J.
name: Beutler, Florian
name: Brinkmann, Jonathan
name: Chuang, Chia-Hsun
name: Cuesta, Antonio J.
name: Eisenstein, Daniel J.
name: Kitaura, Francisco-Shu
name: Koyama, Kazuya
name: L'Huillier, Benjamin
name: Nichol, Robert C.
name: Pieri, Matthew M.
name: Rodriguez-Torres, Sergio
name: Ross, Ashley J.
name: Rossi, Graziano
name: Sánchez, Ariel G.
name: Shafieloo, Arman
name: Tinker, Jeremy L.
name: Tojeiro, Rita
name: Vazquez, Jose A.
name: Zhang, Hanyu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A flat Friedman-Roberson-Walker universe dominated by a cosmological constant ($Λ$) and cold dark matter (CDM) has been the working model preferred by cosmologists since the discovery of cosmic acceleration. However, tensions of various degrees of significance are known to be present among existing datasets within the $Λ$CDM framework. In particular, the Lyman-$α$ forest measurement of the Baryon Acoustic Oscillations (BAO) by the Baryon Oscillation Spectroscopic Survey (BOSS) prefers a smaller value of the matter density fraction $Ω_{\rm M}$ compared to the value preferred by cosmic microwave background (CMB). Also, the recently measured value of the Hubble constant, $H_0=73.24\pm1.74 \ {\rm km}\ {\rm s}^{-1} \ {\rm Mpc}^{-1}$, is $3.4σ$ higher than $66.93\pm0.62 \ {\rm km}\ {\rm s}^{-1} \ {\rm Mpc}^{-1}$ inferred from the Planck CMB data. In this work, we investigate if these tensions can be interpreted as evidence for a non-constant dynamical dark energy (DE). Using the Kullback-Leibler (KL) divergence to quantify the tension between datasets, we find that the tensions are relieved by an evolving DE, with the dynamical DE model preferred at a $3.5σ$ significance level based on the improvement in the fit alone. While, at present, the Bayesian evidence for the dynamical DE is insufficient to favour it over $Λ$CDM, we show that, if the current best fit DE happened to be the true model, it would be decisively detected by the upcoming DESI survey.
description: 27 pages, 3 figures and one table. A supplementary document is included. The BOSS DR12 BAO data used in the work can be downloaded from the SDSS website https://sdss3.org//science/boss_publications.php (check https://data.sdss.org/sas/dr12/boss/papers/clustering/Zhao_etal_2016_DR12COMBINED_tomoBAO_powspec.tar.gz for the tomographic BAO measurement presented in https://arxiv.org/abs/1607.03153)
Flux eruption events drive angular momentum transport in magnetically arrested accretion flows
Creators: name: Chatterjee, Koushik
name: Narayan, Ramesh
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We evolve two high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations of advection-dominated accretion flows around non-spinning black holes (BHs), each over a duration $\sim 3\times 10^5\,GM_{\rm BH}/c^3$. One model captures the evolution of a weakly magnetized (SANE) disk and the other a magnetically arrested disk (MAD). Magnetic flux eruptions in the MAD model push out gas from the disk and launch strong winds with outflow efficiencies at times reaching $10\%$ of the incoming accretion power. Despite the substantial power in these winds, average mass outflow rates remain small out to a radius $\sim100\,GM_{\rm BH}/c^2$, only reaching $\sim 60-80\%$ of the horizon accretion rate. The average outward angular momentum transport is primarily radial in both modes of accretion, but with a clear distinction: magnetic flux eruption-driven disk winds cause a strong vertical flow of angular momentum in the MAD model, while for the SANE model, the magnetorotational instability (MRI) moves angular momentum mostly equatorially through the disk. Further, we find that the MAD state is highly transitory and non-axisymmetric, with the accretion mode often changing to a SANE-like state following an eruption before reattaining magnetic flux saturation with time. The Reynolds stress changes direction during such transitions, with the MAD (SANE) state showing an inward (outward) stress, possibly pointing to intermittent MRI-driven accretion in MADs. Pinning down the nature of flux eruptions using next-generation telescopes will be crucial in understanding the flow of mass, magnetic flux and angular momentum in sub-Eddington accreting BHs like M87$^*$ and Sagittarius A$^*$.
description: Submitted to ApJ. Comments are welcome
Suppressing correlations in massively parallel simulations of lattice models
Creators: name: Kelling, Jeffrey
name: Ódor, Géza
name: Gemming, Sibylle
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: For lattice Monte Carlo simulations parallelization is crucial to make studies of large systems and long simulation time feasible, while sequential simulations remain the gold-standard for correlation-free dynamics. Here, various domain decomposition schemes are compared, concluding with one which delivers virtually correlation-free simulations on GPU Extensive simulations of the octahedron model for $2+1$ dimensional Karda--Parisi--Zhang surface growth, which is very sensitive to correlation in the site-selection dynamics, were performed to show self-consistency of the parallel runs and agreement with the sequential algorithm. We present a GPU implementation providing a speedup of about $30\times$ over a parallel CPU implementation on a single socket and at least $180\times$ with respect to the sequential reference.
description: 9 pages, 7 figures
Characteristic spectra of circuit quantum electrodynamics systems from the ultrastrong- to the deep-strong-coupling regime
Creators: name: Yoshihara, Fumiki
name: Fuse, Tomoko
name: Ashhab, Sahel
name: Kakuyanagi, Kosuke
name: Saito, Shiro
name: Semba, Kouichi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report on spectra of circuit-quantum-electrodynamics (QED) systems in an intermediate regime that lies between the ultrastrong and deep-strong-coupling regimes, which have been reported previously in the literature. Our experimental results, along with numerical simulations, demonstrate that as the coupling strength increases, the spectrum of a circuit-QED system undergoes multiple qualitative transformations, such that several coupling regimes are identified, each with its own unique spectral features. The different spectral transformations can be related to crossings between energy level differences and to changes in the symmetries of the energy eigenstates. These results allow us to use qualitative spectral features to infer certain properties and parameters of the system.
description: 7 figures
Relaxation and coarsening of weakly-interacting breathers in a simplified DNLS chain
Creators: name: Iubini, Stefano
name: Politi, Antonio
name: Politi, Paolo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The Discrete NonLinear Schrödinger (DNLS) equation displays a parameter region characterized by the presence of localized excitations (breathers). While their formation is well understood and it is expected that the asymptotic configuration comprises a single breather on top of a background, it is not clear why the dynamics of a multi-breather configuration is essentially frozen. In order to investigate this question, we introduce simple stochastic models, characterized by suitable conservation laws. We focus on the role of the coupling strength between localized excitations and background. In the DNLS model, higher breathers interact more weakly, as a result of their faster rotation. In our stochastic models, the strength of the coupling is controlled directly by an amplitude-dependent parameter. In the case of a power-law decrease, the associated coarsening process undergoes a slowing down if the decay rate is larger than a critical value. In the case of an exponential decrease, a freezing effect is observed that is reminiscent of the scenario observed in the DNLS. This last regime arises spontaneously when direct energy diffusion between breathers and background is blocked below a certain threshold.
Machine-Learning-Enhanced Optimization of Noise-Resilient Variational Quantum Eigensolvers
Creators: name: Nicoli, Kim A.
name: Wagner, Luca J.
name: Funcke, Lena
Publisher: name: arXiv
Year: 2025
Subjects: subject: Quantum Physics (quant-ph)
subject: Machine Learning (cs.LG)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Variational Quantum Eigensolvers (VQEs) are a powerful class of hybrid quantum-classical algorithms designed to approximate the ground state of a quantum system described by its Hamiltonian. VQEs hold promise for various applications, including lattice field theory. However, the inherent noise of Noisy Intermediate-Scale Quantum (NISQ) devices poses a significant challenge for running VQEs as these algorithms are particularly susceptible to noise, e.g., measurement shot noise and hardware noise.
 In a recent work, it was proposed to enhance the classical optimization of VQEs with Gaussian Processes (GPs) and Bayesian Optimization, as these machine-learning techniques are well-suited for handling noisy data. In these proceedings, we provide additional insights into this new algorithm and present further numerical experiments. In particular, we examine the impact of hardware noise and error mitigation on the algorithm's performance. We validate the algorithm using classical simulations of quantum hardware, including hardware noise benchmarks, which have not been considered in previous works. Our numerical experiments demonstrate that GP-enhanced algorithms can outperform state-of-the-art baselines, laying the foundation for future research on deploying these techniques to real quantum hardware and lattice field theory setups.
description: 14 pages, 3 figures, contribution to the 41st International Symposium on Lattice Field Theory (Lattice 2024), July 28th - August 3rd, 2024, Liverpool, UK
Thermal radiative corrections to hyperfine structure of light hydrogen-like systems
Creators: name: Zalialiutdinov, T.
name: Glazov, D.
name: Solovyev, D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: In this work, we consider the thermal correction to the hyperfine interaction in hydrogen, deuterium, and the $^3$He$^+$ ion. This correction is effectively described by one-loop Feynman graphs in the framework of the quantum electrodynamics theory for bound states at a finite temperature. A simple analysis shows the importance of the obtained results for future prospects for measuring hyperfine splitting. In addition, the application for testing the time variation of fundamental constants is briefly discussed.
The Apparently Decaying Orbit of WASP-12
Creators: name: Patra, Kishore C.
name: Winn, Joshua N.
name: Holman, Matthew J.
name: Yu, Liang
name: Deming, Drake
name: Dai, Fei
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We present new transit and occultation times for the hot Jupiter WASP-12b. The data are compatible with a constant period derivative: $\dot{P}=-29 \pm 3$ ms yr$^{-1}$ and $P/\dot{P}= 3.2$ Myr. However, it is difficult to tell whether we have observed orbital decay, or a portion of a 14-year apsidal precession cycle. If interpreted as decay, the star's tidal quality parameter $Q_\star$ is about $2\times 10^5$. If interpreted as precession, the planet's Love number is $0.44\pm 0.10$. Orbital decay appears to be the more parsimonious model: it is favored by $Δχ^2=5.5$ despite having two fewer free parameters than the precession model. The decay model implies that WASP-12 was discovered within the final $\sim$0.2% of its existence, which is an unlikely coincidence but harmonizes with independent evidence that the planet is nearing disruption. Precession does not invoke any temporal coincidence, but does require some mechanism to maintain an eccentricity of $\approx$0.002 in the face of rapid tidal circularization. To distinguish unequivocally between decay and precession will probably require a few more years of monitoring. Particularly helpful will be occultation timing in 2019 and thereafter.
description: 10 pages [AAS journals, in press, note added in proof]
FUMES III: Ultraviolet and Optical Variability of M Dwarf Chromospheres
Creators: name: Duvvuri, Girish M.
name: Pineda, J. Sebastian
name: Berta-Thompson, Zachory K.
name: France, Kevin
name: Youngblood, Allison
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We obtained ultraviolet and optical spectra for 9 M~dwarfs across a range of rotation periods to determine whether they showed stochastic intrinsic variability distinguishable from flares. The ultraviolet spectra were observed during the Far Ultraviolet M~Dwarf Evolution Survey \emph{Hubble~Space~Telescope} program using the Space Telescope Imaging Spectrograph. The optical observations were taken from the Apache Point Observatory 3.5-meter telescope using the Dual Imaging Spectrograph and from the Gemini South Observatory using the Gemini Multi-Object Spectrograph. We used the optical spectra to measure multiple chromospheric lines: the Balmer series from H$α$ to H$10$ and the \ion{Ca}{2}~H and K lines. We find that after excising flares, these lines vary on the order of $1-20\%$ at minute-cadence over the course of an hour. The absolute amplitude of variability was greater for the faster rotating M~dwarfs in our sample. Among the 5 stars for which measured the weaker Balmer lines, we note a tentative trend that the fractional amplitude of the variability increases for higher order Balmer lines. We measured the integrated flux of multiple ultraviolet emission features formed in the transition region: the \ion{N}{5}, \ion{Si}{4} and \ion{C}{4} resonance line doublets, and the \ion{C}{2} and \ion{He}{2} multiplets. The signal-to-noise (S/N) ratio of the UV data was too low for us to detect non-flare variability at the same scale and time cadence as the optical. We consider multiple mechanisms for the observed stochastic variability and propose both observational and theoretical avenues of investigation to determine the physical causes of intrinsic variability in the chromospheres of M~dwarfs.
Almost periodic functions on the quantum time scale and applications
Creators: name: Li, Yongkun
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: In this paper, we first propose two types of concepts of almost periodic functions on the quantum time scale. Secondly, we study some basic properties of almost periodic functions on the quantum time scale. Thirdly, based on these, we study the existence and uniqueness of almost periodic solutions of dynamic equations on the quantum time scale by Lyapunov method. Then, we give a equivalent definition of almost periodic functions on the quantum time scale. Finally, as an application, we propose a class of high-order Hopfield neural networks on the quantum time scale and establish the existence of almost periodic solutions of this class of neural networks.
description: 23 pages
HALOGAS: Strong Constraints on the Neutral Gas Reservoir and Accretion Rate in Nearby Spiral Galaxies
Creators: name: Kamphuis, P.
name: Jütte, E.
name: Heald, G. H.
name: Ruiz, N. Herrera
name: Józsa, G. I. G.
name: de Blok, W. J. G.
name: Serra, P.
name: Marasco, A.
name: Dettmar, R. -J.
name: Pingel, N. M.
name: Oosterloo, T.
name: Rand, R. J.
name: Walterbos, R. A. M.
name: van der Hulst, J. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Galaxies in the local Universe are thought to require ongoing replenishment of their gas reservoir in order to maintain the observed star formation rates. Cosmological simulations predict that such accretion can occur in both a dynamically hot and cold mode. However, until now observational evidence of the accretion required to match the observed star formation histories is lacking. This paper attempts to determine whether galaxies in the local Universe possess a significant reservoir of HI and what would be the accretion rates derived from such reservoirs. We search the vicinity of 22 nearby galaxies for isolated HI clouds or distinct streams in a systematic and automated manner. The HALOGAS observations represent one of the most sensitive and detailed HI surveys to date. These observations typically reach column density sensitivities of 10^19 cm^-2 over a 20 km/s width. We find 14 secure HI cloud candidates without an observed optical counterpart. These cloud candidates appear to be analogues to the most massive clouds detected around the Milky Way and M31. However, on average their numbers seem significantly reduced. We constrain upper limits for HI accretion in the local Universe. The average HI mass currently observed amounts to a rate of 0.05 Msun/yr with a stringent upper limit of 0.22 Msun/yr, confirming previous estimates. This is much lower than the average star formation rate in this sample. Our best estimate, based on GBT detection limits of several galaxies, suggests that another 0.04 Msun/yr could be accreted from undetected clouds and streams. These results show that in nearby galaxies HI is not being accreted at the same rate as stars are currently being formed. Our study can not exclude that other forms of gas accretion are at work. However, these observations also do not reveal extended neutral gas reservoirs around most nearby spiral galaxies.
description: Accepted for publication in Astronomy & Astrophysics section 4. Extragalactic astronomy. Data available at https://www.astron.nl/halogas/data.php
Global $Λ$ polarization in heavy-ion collisions from a transport model
Creators: name: Li, Hui
name: Pang, Long-Gang
name: Wang, Qun
name: Xia, Xiao-Liang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The polarizations of $Λ$ and $\barΛ$ hyperons are important quantities in extracting the fluid vorticity of the strongly coupled quark gluon plasma and the magnitude of the magnetic field created in off-central heavy-ion collisions, through the spin-vorticity and spin-magnetic coupling. We computed the energy dependence of the global $Λ$ polarization in off-central Au+Au collisions in the energy range $\sqrt{s_{NN}}=7.7-200$ GeV using a multiphase transport model. The observed polarizations with two different impact parameters agree quantitatively with recent STAR measurements. The energy dependence of the global $Λ$ polarization is decomposed as energy dependence of the $Λ$ distribution at hadronization and the space-time distribution of the fluid-vorticity field. The visualization of both the $Λ$ distribution and the fluid-vorticity field show a smaller tilt at higher collisional energies, which indicates that the smaller global polarization at higher collisional energies is caused by a smaller angular momentum deposition at midrapidity.
description: RevTex 4-1, 7 pages, 6 figures, to appear in Phys. Rev. C
Internal rotation and buoyancy travel time of 60 gamma Doradus stars from uninterrupted TESS light curves spanning 352 days
Creators: name: Garcia, Stefano
name: Van Reeth, Timothy
name: De Ridder, Joris
name: Aerts, Conny
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Gamma Doradus (hereafter $γ$~Dor) stars are gravity-mode pulsators whose periods carry information about the internal structure of the star. These periods are especially sensitive to the internal rotation and chemical mixing, two processes that are currently not well constrained in the theory of stellar evolution. Aims. We aim to identify the pulsation modes and deduce the internal rotation and buoyancy travel time for 106 $γ$ Dor stars observed by the Transiting Exoplanet Survey Satellite (TESS) mission in its southern continuous viewing zone (hereafter S-CVZ). We rely on 140 previously detected period-spacing patterns, that is, series of (near-)consecutive pulsation mode periods. Methods. We used the asymptotic expression to compute gravity-mode frequencies for ranges of the rotation rate and buoyancy travel time that cover the physical range in $γ$~Dor stars. Those frequencies were fitted to the observed period-spacing patterns by minimising a custom cost function. The effects of rotation were evaluated using the traditional approximation of rotation, using the stellar pulsation code GYRE. Results. We obtained the pulsation mode identification, internal rotation and buoyancy travel time for 60 TESS $γ$~Dor stars. For the remaining 46 targets, the detected patterns are either too short or contained too many missing modes for unambiguous mode identification, and longer light curves are required. For the successfully analysed stars, we found that period-spacing patterns from 1-yr long TESS light curves can constrain the internal rotation and buoyancy travel time to a precision of $\rm 0.03~d^{-1}$ and 400s, respectively, which is about half as precise as literature results based on 4-yr Kepler light curves of $γ$~Dor stars.
description: 16 pages, 21 figures, 5 tables. Accepted for publication in Astronomy and Astrophysics
Dynamics and Morphology of the Milky Way Spiral Arms from the Metallicity Distribution and Radial Mixing
Creators: name: Martinez-Medina, L. A.
name: Pichardo, B.
name: Peimbert, A.
name: Carigi, L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Albeit radial migration must be a ubiquitous process in disc galaxies, its significance in the evolution of stellar discs is not always reflected through global trends. However, there are other key observables, such as the metallicity distribution function (MDF), that may shed some light in this matter. We argue that the shape of the MDF not only tells us whether the stellar disc experienced radial migration, but it also contains important clues on the structure that triggered it. Specifically, the MDF contains information about the dynamics and morphology of the spiral pattern. To constrain the spiral parameters, we have included a detailed chemical tagging in our simulations; this allows us to produce a restriction of the structural parameters of the spiral arms in the Milky Way as well as a method to constrain chemical evolution models towards the center of the Galactic disc, where no chemical model provides information. We also found that it is unlikely that the Sun was formed near its current galactocentric position, therefore it might be inaccurate to consider the Sun as representative of the chemical abundances in the solar neighborhood. We also show that a stellar disc of the Milky Way, after evolving dynamically and chemically for 5 Gyr, preserves 80% of its original global metallicity gradient despite having suffered important heating and radial migration; this means that the presence of a metallicity gradient in a given galaxy, does not guarantee that radial mixing has not played a role in its evolution.
description: 15 pages, 17 Figures, 3 Tables. Accepted for publication in MNRAS
title: The importance of mineralogy for a circular economy of the construction sector - examples from the ReMin funding initiative
Creators: name: Gentzmann, Marie C.
name: Henning, Sören
name: Szurlies, Michael
name: Brämer, Thilo
name: Bertram, Andre
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
One of the challenges on the way towards a more sustainable future is the transition from linear to circular economy (CE). The need to conserve and substitute primary raw materials wherever possible has driven research and development to study the potential of wastes and residues as important resources. The construction sector, in particular, has great potential to reduce parts of its high primary raw material demand by using mineral residues from various sources.In the presented funding initiative “ReMin” (“Ressourceneffiziente Kreislaufwirtschaft ─ Bauen und mineralische Stoffkreisläufe“) 16 research projects deal with resource efficient CE approaches. They aim to use construction and demolition wastes, metallurgical slags, incineration bottom ashes (IBA), mine tailings and other residues for the development of new construction materials. In this context, the investigation of the mineralogy and chemistry of the materials and processes is fundamentally important. Geoscientific aspects within the projects include e.g. the understanding of cement-clinker formation from thermally treated slags, the efficient separation of metallic and non-metallic particles in the fine fractions of IBA or mine tailings and the species and chemical bonding and behavior of heavy metals in waste streams. Other topics are the safe detection and separation of asbestos in mixed construction wastes and the investigation of the recycling potential of e.g. alternative gypsum sources. The accompanying research project “TReMin” with partners from CUTEC, Fraunhofer IWKS and BGR aims to support those research actions by networking and transfer of the results within and beyond ReMin and on a national and European level.
Long-term Photometric Study of the Pre-main Sequence Star V1180 Cas
Creators: name: Mutafov, Asen
name: Semkov, Evgeni
name: Peneva, Stoyanka
name: Ibryamov, Sunay
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this paper results from the optical photometric observations of the pre-main-sequence star V1180 Cas are reported. The star is a young variable associated with the dark cloud Lynds 1340, located at a distance of 600 pc from the Sun in the star forming region in Cassiopeia. V1180 Cas shows a large amplitude variability interpreted as a combination of accretion-induced and extinction-driven effects. Our data from VRI CCD photometric observations of the star are collected from September 2011 to February 2022. During our monitoring, we recorded several brightness dips with large amplitudes of up to 5 mag. (I-band). At the same time, increases in brightness over periods of several weeks have also been recorded. In this paper, we compare the photometric data obtained for V1180 Cas with observations of other low-mass pre-main sequence objects.
description: 11 pages, 3 figures, accepted for publication in RAA
Non-Iterative SLAM
Creators: name: Wang, Chen
name: Yuan, Junsong
name: Xie, Lihua
Publisher: name: arXiv
Year: 2017
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The goal of this paper is to create a new framework for dense SLAM that is light enough for micro-robot systems based on depth camera and inertial sensor. Feature-based and direct methods are two mainstreams in visual SLAM. Both methods minimize photometric or reprojection error by iterative solutions, which are computationally expensive. To overcome this problem, we propose a non-iterative framework to reduce computational requirement. First, the attitude and heading reference system (AHRS) and axonometric projection are utilized to decouple the 6 Degree-of-Freedom (DoF) data, so that point clouds can be matched in independent spaces respectively. Second, based on single key-frame training, the matching process is carried out in frequency domain by Fourier transformation, which provides a closed-form non-iterative solution. In this manner, the time complexity is reduced to $\mathcal{O}(n \log{n})$, where $n$ is the number of matched points in each frame. To the best of our knowledge, this method is the first non-iterative and online trainable approach for data association in visual SLAM. Compared with the state-of-the-arts, it runs at a faster speed and obtains 3-D maps with higher resolution yet still with comparable accuracy.
description: This paper got the best paper award in robotic planning on 18th International Conference on Advanced Robotics (ICAR 2017)
Crossing Symmetry in Alpha Space
Creators: name: Hogervorst, Matthijs
name: van Rees, Balt C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We initiate the study of the conformal bootstrap using Sturm-Liouville theory, specializing to four-point functions in one-dimensional CFTs. We do so by decomposing conformal correlators using a basis of eigenfunctions of the Casimir which are labeled by a complex number alpha. This leads to a systematic method for computing conformal block decompositions. Analyzing bootstrap equations in alpha space turns crossing symmetry into an eigenvalue problem for an integral operator K. The operator K is closely related to the Wilson transform, and some of its eigenfunctions can be found in closed form.
description: 34 pages, 3 figures. v2: some minor changes and added subsection 2.3 on convergence
Viscous Drude weight of dual Bose and Fermi gases in one dimension
Creators: name: Nishida, Yusuke
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We continue to study frequency-dependent complex bulk viscosities of one-dimensional Bose and Fermi gases with contact interactions, which exhibit the weak-strong duality according to our recent work. Here we show that they are contributed to by Drude peaks divergent at zero frequency as typical for transport coefficients of quantum integrable systems in one dimension. In particular, their Drude weights are evaluated based on the Kubo formula in the high-temperature limit at arbitrary coupling as well as in the weak-coupling and strong-coupling limits at arbitrary temperature, where systematic expansions in terms of small parameters are available. In all three limits, the Drude peaks are found at higher orders compared to the finite regular parts.
description: 8 pages, 8 figures; published version