cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dynamical mechanisms for deuteron production at mid-rapidity in relativistic heavy-ion collisions from SIS to RHIC energies
Creators: name: Coci, Gabriele
name: Gläßel, Susanne
name: Kireyeu, Viktar
name: Aichelin, Jörg
name: Blume, Christoph
name: Bratkovskaya, Elena
name: Kolesnikov, Vadim
name: Voronyuk, Vadim
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The understanding of the mechanisms for the production of weakly bound clusters, such as a deuteron $d$, in heavy-ion reactions at mid-rapidity is presently one of the challenging problems which is also known as the "ice in a fire" puzzle. In this study we investigate the dynamical formation of deuterons within the Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) microscopic transport approach and advance two microscopic production mechanisms to describe deuterons in heavy-ion collisions from SIS to RHIC energies: kinetic production by hadronic reactions and potential production by the attractive potential between nucleons. Differently to other studies, for the "kinetic" deuterons we employ the full isospin decomposition of the various $πNN\leftrightarrow πd$, $NNN\leftrightarrow N d$ channels and take into account the finite size properties of the deuteron by means of an excluded volume condition in coordinate space and by the projection onto the deuteron wave function in momentum space. We find that considering the quantum nature of the deuteron in coordinate and momentum space reduces substantially the kinetic deuteron production in a dense medium as encountered in heavy-ion collisions. If we add the "potential" deuterons by applying an advanced Minimum Spanning Tree (aMST) procedure, we obtain good agreement with the available experimental data from SIS energies up to the top RHIC energy.
description: 35 pages, 24 figures
Adaptive multiscale model reduction with Generalized Multiscale Finite Element Methods
Creators: name: Chung, Eric
name: Efendiev, Yalchin
name: Hou, Thomas Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper, we discuss a general multiscale model reduction framework based on multiscale finite element methods. We give a brief overview of related multiscale methods. Due to page limitations, the overview focuses on a few related methods and is not intended to be comprehensive. We present a general adaptive multiscale model reduction framework, the Generalized Multiscale Finite Element Method. Besides the method's basic outline, we discuss some important ingredients needed for the method's success. We also discuss several applications. The proposed method allows performing local model reduction in the presence of high contrast and no scale separation.
Balancing act: multivariate rational reconstruction for IBP
Creators: name: Belitsky, A. V.
name: Smirnov, A. V.
name: Yakovlev, R. V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We address the problem of unambiguous reconstruction of rational functions of many variables. This is particularly relevant for recovery of exact expansion coefficients in integration-by-parts identites (IBPs) based on modular arithmetic. These IBPs are indispensable in modern approaches to evaluation of multiloop Feynman integrals by means of differential equations. Modular arithmetic is far more superior to algebraic implementations when one deals with high-multiplicity situations involving a large number of Lorentz invariants. We introduce a new method based on balanced relations which allows one to achieve the goal of a robust functional restoration with minimal data input. The technique is implemented as a Mathematica package Reconstruction.m in the FIRE6 environment and thus successfully demonstrates a proof of concept.
description: 15 pages, 10 ancillary files with code, scripts and demo; download code @ https://bitbucket.org/feynmanIntegrals/fire/src/master/FIRE6/mm/
Semantic Localization in the PCL library
Creators: name: Martínez-Gómez, Jesús
name: Morell, Vicente
name: Cazorla, Miguel
name: García-Varea, Ismael
Publisher: name: arXiv
Year: 2016
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The semantic localization problem in robotics consists in determining the place where a robot is located by means of semantic categories. The problem is usually addressed as a supervised classification process, where input data correspond to robot perceptions while classes to semantic categories, like kitchen or corridor. In this paper we propose a framework, implemented in the PCL library, which provides a set of valuable tools to easily develop and evaluate semantic localization systems. The implementation includes the generation of 3D global descriptors following a Bag-of-Words approach. This allows the generation of dimensionality-fixed descriptors from any type of keypoint detector and feature extractor combinations. The framework has been designed, structured and implemented in order to be easily extended with different keypoint detectors, feature extractors as well as classification models. The proposed framework has also been used to evaluate the performance of a set of already implemented descriptors, when used as input for a specific semantic localization system. The results obtained are discussed paying special attention to the internal parameters of the BoW descriptor generation process. Moreover, we also review the combination of some keypoint detectors with different 3D descriptor generation techniques.
description: 19 pages, 6 figures, ISSN 0921-8890
Adaptive multi-stage integration schemes for Hamiltonian Monte Carlo
Creators: name: Nagar, Lorenzo
name: Fernández-Pendás, Mario
name: Sanz-Serna, Jesús María
name: Akhmatskaya, Elena
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation (stat.CO)
subject: Numerical Analysis (math.NA)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Hamiltonian Monte Carlo (HMC) is a powerful tool for Bayesian statistical inference due to its potential to rapidly explore high dimensional state space, avoiding the random walk behavior typical of many Markov Chain Monte Carlo samplers. The proper choice of the integrator of the Hamiltonian dynamics is key to the efficiency of HMC. It is becoming increasingly clear that multi-stage splitting integrators are a good alternative to the Verlet method, traditionally used in HMC. Here we propose a principled way of finding optimal, problem-specific integration schemes (in terms of the best conservation of energy for harmonic forces/Gaussian targets) within the families of 2- and 3-stage splitting integrators. The method, which we call Adaptive Integration Approach for statistics, or s-AIA, uses a multivariate Gaussian model and simulation data obtained at the HMC burn-in stage to identify a system-specific dimensional stability interval and assigns the most appropriate 2-/3-stage integrator for any user-chosen simulation step size within that interval. s-AIA has been implemented in the in-house software package HaiCS without introducing computational overheads in the simulations. The efficiency of the s-AIA integrators and their impact on the HMC accuracy, sampling performance and convergence are discussed in comparison with known fixed-parameter multi-stage splitting integrators (including Verlet). Numerical experiments on well-known statistical models show that the adaptive schemes reach the best possible performance within the family of 2-, 3-stage splitting schemes.
Higher-spin Interactions from CFT: The Complete Cubic Couplings
Creators: name: Sleight, Charlotte
name: Taronna, Massimo
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this letter we provide a complete holographic reconstruction of the cubic couplings in the minimal bosonic higher-spin theory in AdS$_{d+1}$. For this purpose we also determine the OPE coefficients of all single-trace conserved currents in the $d$-dimensional free scalar $O\left(N\right)$ vector model, and compute the tree-level three-point Witten diagram amplitudes for a generic cubic interaction of higher-spin gauge fields in the metric-like formulation.
description: 11+7 pages, 1 figure. v2: A few clarifications, including an appendix on the intrinsic form of the vertices and consistency with Noether procedure. Typos corrected, references added. v3: Appendix with off-shell completion of couplings in the de Donder gauge added
Machine learning for phase ordering dynamics of charge density waves
Creators: name: Cheng, Chen
name: Zhang, Sheng
name: Chern, Gia-Wei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We present a machine learning (ML) framework for large-scale dynamical simulations of charge density wave (CDW) states. The charge modulation in a CDW state is often accompanied by a concomitant structural distortion, and the adiabatic evolution of a CDW order is governed by the dynamics of the lattice distortion. Calculation of the electronic contribution to the driving forces, however, is computationally very expensive for large systems. Assuming the principle of locality for electron systems, a neural-network model is developed to accurately and efficiently predict local electronic forces with input from neighborhood configurations. Importantly, the ML model makes possible a linear complexity algorithm for dynamical simulations of CDWs. As a demonstration, we apply our approach to investigate the phase ordering dynamics of the Holstein model, a canonical system of CDW order. Our large-scale simulations uncover an intriguing growth of the CDW domains that deviates significantly from the expected Allen-Cahn law for phase ordering of Ising-type order parameter field. This anomalous domain-growth could be attributed to the complex structure of domain-walls in this system. Our work highlights the promising potential of ML-based force-field models for dynamical simulations of functional electronic materials.
description: 16 pages, 9 figures
On Hermitian separability of the next-to-leading order BFKL kernel for the adjoint representation of the gauge group in the planar N = 4 SYM
Creators: name: Fadin, V. S.
name: Fiore, R.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We analyze a modification of the BFKL kernel for the adjoint representation of the colour group in the maximally supersymmetric (N=4) Yang-Mills theory in the limit of a large number of colours, related to the modification of the eigenvalues of the kernel suggested by S. Bondarenko and A. Prygarin in order to reach the Hermitian separability of the eigenvalues. We restore the modified kernel in the momentum space. It turns out that the modification is related only to the real part of the kernel and that the correction to the kernel can not be presented by a single analytic function in the entire momentum region, which contradicts the known properties of the kernel.
Active galactic nuclei feedback in an elliptical galaxy (III): the impacts and fate of cosmological inflow
Creators: name: Zhu, Bocheng
name: Yuan, Feng
name: Ji, Suoqing
name: Peng, Yingjie
name: Ho, Luis C.
name: Ostriker, Jeremiah P.
name: Ciotti, Luca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The cosmological inflow of a galaxy is speculated to be able to enter the galaxy and enhance the star formation rate (SFR) and black hole accretion rate (BHAR). In this paper, by performing high-resolution hydrodynamic simulations in the framework of {\it MACER}, we investigate the fate of the inflow and its impacts on the evolution of a massive elliptical galaxy. The inflow properties are adopted from the cosmological simulation IllustrisTNG. We find that, the inflow gas hardly enters but is blocked beyond $\sim 20$ kpc from the central galaxy and becomes part of the circumgalactic medium (CGM). The gas pressure gradient, mainly contributed by the thermalized stellar wind and subdominantly by the energy input from the AGN, balances gravity and prevents the inflow from entering the galaxy. The SFR and BHAR are almost not affected by the normal inflow. However, if the rate of cosmological inflow were increased by a factor of 3, a small fraction of the inflow would enter the galaxy and contribute about 10\% of the gas in the galaxy. In this case, the gas density in the galaxy would increase by a factor of $\ga$ 20. This increase is not because of the additional gas supply by the inflow but the increase of gas density in the CGM caused by the inflow. Consequently, the SFR and BHAR would increase by a factor of $\sim$ 5 and $\sim 1000$ respectively. Finally, AGN feedback can perturb the motion of the inflow and heat the CGM through its intermittent outbursts.
description: 19 pages,13 figures, accepted for publication in MNRAS
Jet-dilepton conversion from an anisotropic quark-gluon plasma
Creators: name: Mukherjee, Arghya
name: Mandal, Mahatsab
name: Roy, Pradip
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the yield of lepton pair production from jet-plasma interaction where the plasma is anisotropic in momentum space. We compare both the $M$ and $p_T$ distributions from such process with the Drell-Yan contribution. It is observed that the invariant mass distribution of lepton pair from such process dominate over the Drell-Yan up to $3$ GeV at RHIC and up to $10$ GeV at LHC. Moreover, it is found that the contribution from anistropic quark gluon plasma (AQGP) increases marginally compared to the isotropic QGP. In case of $p_T$-distribution we observe an increase by a factor of $3-4$ in the entire $p_T$-range at RHIC for AQGP. However, at LHC the change in the $p_T$-distribution is marginal as compared to the isotropic case.
description: 8 pages, 3 figures
Characterisation of stellar activity of M dwarfs. I. Long-timescale variability in a large sample and detection of new cycles
Creators: name: Mignon, L.
name: Meunier, N.
name: Delfosse, X.
name: Bonfils, X.
name: Santos, N. C.
name: Forveille, T.
name: Gaisné, G.
name: Astudillo-Defru, N.
name: Lovis, C.
name: Udry, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: M dwarfs are active stars that exhibit variability in chromospheric emission and photometry at short and long timescales, including long cycles that are related to dynamo processes. This activity also impacts the search for exoplanets because it affects the radial velocities. We analysed a large sample of 177 M dwarfs observed with HARPS (2003-2020) in order to characterise the long-term variability of these stars. We compared the variability obtained in three chromospheric activity indices (Ca II H & K, the Na D doublet, and Halpha) and with ASAS photometry. We focused on the detailed analysis of the chromospheric emission based on linear, quadratic, and sinusoidal models. We used various tools to estimate the significance of the variability and to quantify the improvement brought by the models. In addition, we analysed complementary photometric time series for the most variable stars to be able to provide a broader view of the long-term variability in M dwarfs. We find that most stars are significantly variable, even the quietest stars. Most stars in our sample (75%) exhibit a long-term variability, which manifests itself mostly through linear or quadratic variability, although the true behaviour may be more complex. We found significant variability with estimated timescales for 24 stars, and estimated the lower limit for a possible cycle period for an additional 9 stars that were not previously published. We found evidence of complex variability because more than one long-term timescale may be present for at least 12 stars, together with significant differences between the behaviour of the three activity indices. This complexity may also be the source of the discrepancies observed between previous publications. We conclude that long-term variability is present for all spectral types and activity level in M dwarfs, without a significant trend with spectral type or mean activity level.
description: article accepted in Astronomy and Astrophysics, February 2023, 31 pages
Galesus (Schizogalesus) distinctus Nixon 1930
Creators: name: Notton, David G.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Diapriidae
Galesus
Galesus distinctus

description: Galesus (Schizogalesus) distinctus Nixon, 1930: 400, 405.
Valid name
Coptera distincta (Nixon, 1930).
Summary of types
Holotype ♀, BMNH number 9.655, by monotypy.
Primary type data
Type; S.Africa/ R.E.Turner/ Brit. Mus./ 1921-315; Mossel bay/ Cape Province / 5-31.vii.1921; Galesus / distinctus/ Nixon/ ♀ type 1930.
Type locality
South Africa, Western Cape Province, Mossel Bay.
Remarks
The holotype is mounted on a card and is entire.
description: Published as part of Notton, David G., 2014, A catalogue of the types of Diapriinae (Hymenoptera, Diapriidae) at the Natural History Museum, London, pp. 1-123 in European Journal of Taxonomy 75 on page 88, DOI: 10.5852/ejt.2014.75, http://zenodo.org/record/3862773
Die Mediziner als Avantgarde der politischen Umgestaltung seit der Tanzimat-Periode
Creators: name: Ağuiçenoğlu, Hüseyin
Publisher: name: Universitäts- und Landesbibliothek Sachsen-Anhalt
Year: 2007
Subjects: subject: Osmanisches Reich
subject: Medizin
subject: 19. Jahrhundert
subject: Tanzimat
subject: DDC::9** Geschichte und Geografie::95* Geschichte Asiens::953 Geschichte der arabischen Halbinsel und benachbarter Gebiete

description: Ziel dieses Artikels ist es, auf den besonderen Beitrag der muslimischen und nichtmuslimischen osmanischen Mediziner sowie der ausländischen Ärzte zur Transformation des Osmanischen Reiches seit dem 19. Jh. hinzuweisen. Dies geschieht vor dem Hintergrund einer kurzen Darstellung des Reformprozesses im Gesundheitswesen.
A systematic review on fish freshness and quality indicators
Creators: name: Férez-Rubio, J.A.
name: García, Míriam R.
name: Vilas, Carlos
Publisher: name: Zenodo
Year: 2022
Subjects: fish quality
fish freshness
bibliographic review
bibliometric analysis

description: This repository contains the bibliometric search results discussed in the manuscript : García, MR, Férez-Rubio, JA, Vilas, C. (2022). Assessment and Prediction of Fish Freshness using Mathematical Modelling: A Review. MDPI Foods, 11(15):2312. DOI:10.3390/foods11152312. Download the zip file and unzip it. Two types of files are contained: - HTLM files. These files contain a structured bibliometric analysis regarding the most commonly used indicators to assess fish quality/freshness. The main file (Appendix_collection.html) contains an summary table. The bibliometric analysis of the different indicators can be accessed from this file in an interactive way, via the corresponding hyperlinks. - PDF files. File "FishQualityBib.pdf" contains the bibliometric analysis of the whole collection (all quality indicators together). File "QualityFish.pdf" contains a separate bibliometric analysis for each quality indicator.
description: This work has been funded by the projects RTI2018-093560-J-I00 (MCIU/AEI/FEDER, UE) and RYC2019-028006-I/AIE/10.13039/501100011033
Warburg's impedance revisited
Creators: name: Barbero, Giovanni
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The derivation of Warburg's impedance presented in several books and scientific papers is reconsidered. It has been obtained by assuming that the total electric current across the sample is just due to the diffusion, and that the external potential applied to the electrode is responsible for an increase of the bulk density of charge described by Nernst's model. We show that these assumptions are not correct, and hence the proposed derivations questionable. A correct determination of the electrochemical impedance of a cell of an insulating material where are injected external charges of a given sign, when the diffusion and the displacement currents are taken into account, does not predict, in the high frequency region, for the real and imaginary parts of the impedance, the trends predicted by Warburg's impedance in the Nernstian approximation. The presented model can be generalized to the case of asymmetric cell, assuming boundary conditions physically sound.
Validating Stellar Abundance Measurements from Multi-Resolution Spectroscopy
Creators: name: Sandford, Nathan R.
name: Weisz, Daniel R.
name: Ting, Yuan-Sen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Large-scale surveys will provide spectroscopy for $\sim$50 million resolved stars in the Milky Way and Local Group. However, these data will have a high degree of heterogeneity and most will be low-resolution ($R<10000$), posing challenges to measuring consistent and reliable stellar labels. Here, we introduce a framework for identifying and remedying these issues. By simultaneously fitting the full spectrum and Gaia photometry with the Payne, we measure $\sim$40 abundances for 8 red giants in M15. From degraded quality Keck/HIRES spectra, we evaluate trends with resolution and S/N and find that (i) $\sim$20 abundances are recovered consistently within $\lesssim$0.1 dex agreement and with $\lesssim$0.05-0.15~dex systematic uncertainties from $10000\lesssim R\lesssim80000$; (ii) for 9 elements (C, Mg, Ca, Sc, Ti, Fe, Ni, Y, Nd), this systematic precision and accuracy extends down to $R\sim2500$; and (iii) while most elements do not exhibit strong S/N-dependent systematics, there are non-negligible biases for 4 elements (C, Mg, Ca, and Dy) below $\text{S/N}\sim10$ pixel$^{-1}$. We compare statistical uncertainties from MCMC sampling to the easier-to-compute Cramér-Rao bounds and find that they agree for $\sim$75% of elements, indicating the latter to be a reliable and faster way to estimate uncertainties. Our analysis illustrates the great promise of low-resolution spectroscopy for stellar chemical abundance work, and ongoing improvements to stellar models (e.g., 3D-NLTE physics) will only further extend its viability to more elements and to higher precision and accuracy.
description: 46 pages, 26 figures, submitted to ApJS. Comments welcome!
Analogies between hadron-in-jet and dihadron fragmentation
Creators: name: Bacchetta, Alessandro
name: Radici, Marco
name: Rossi, Lorenzo
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We describe the formal analogies in the description of the inclusive production in hard processes of hadron pairs (based on dihadron fragmentation functions) and of a single hadron inside a jet (based on hadron-in-jet fragmentation functions). Since several observables involving dihadron fragmentation functions have been proposed in the past, we are able to suggest new interesting observables involving hadron-in-jet fragmentation functions, in lepton-hadron deep-inelastic scattering and hadronic collisions.
description: 18 pages, 6 (composite) figures
A State-of-the-art Integrated Transportation Simulation Platform
Creators: name: Azevedo, Tiago
name: Rossetti, Rosaldo J. F.
name: Barbosa, Jorge G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Multiagent Systems (cs.MA)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Nowadays, universities and companies have a huge need for simulation and modelling methodologies. In the particular case of traffic and transportation, making physical modifications to the real traffic networks could be highly expensive, dependent on political decisions and could be highly disruptive to the environment. However, while studying a specific domain or problem, analysing a problem through simulation may not be trivial and may need several simulation tools, hence raising interoperability issues. To overcome these problems, we propose an agent-directed transportation simulation platform, through the cloud, by means of services. We intend to use the IEEE standard HLA (High Level Architecture) for simulators interoperability and agents for controlling and coordination. Our motivations are to allow multiresolution analysis of complex domains, to allow experts to collaborate on the analysis of a common problem and to allow co-simulation and synergy of different application domains. This paper will start by presenting some preliminary background concepts to help better understand the scope of this work. After that, the results of a literature review is shown. Finally, the general architecture of a transportation simulation platform is proposed.
An extension result for $(LB)$-spaces and the surjectivity of tensorized mappings
Creators: name: Debrouwere, Andreas
name: Neyt, Lenny
Publisher: name: arXiv
Year: 2023
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46M18, 46A22, 46A32, 46A13, 46A63

description: We study an extension problem for continuous linear maps in the setting of $(LB)$-spaces. More precisely, we characterize the pairs $(E,Z)$, where $E$ is a locally complete space with a fundamental sequence of bounded sets and $Z$ is an $(LB)$-space, such that for every exact sequence of $(LB)$-spaces $$ 0 \rightarrow X \xrightarrowι Y \rightarrow Z \rightarrow 0$$ the map $$ L(Y,E) \to L(X, E), ~ T \mapsto T \circ ι$$ is surjective, meaning that each continuous linear map $X \to E$ can be extended to a continuous linear map $Y \to E$ via $ι$, under some mild conditions on $E$ or $Z$ (e.g. one of them is nuclear). We use our extension result to obtain sufficient conditions for the surjectivity of tensorized maps between Fréchet-Schwartz spaces. As an application of the latter, we study vector-valued Eidelheit type problems. Our work is inspired by and extends results of Vogt [24].
description: 30 pages
Machine Learning Models Capture Plasmon Dynamics in Ag Nanoparticles
Creators: name: Habib, Adela
name: Lubbers, Nicholas
name: Tretiak, Sergei
name: Nebgen, Benjamin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Highly energetic electron-hole pairs (hot carriers) formed from plasmon decay in metallic nanostructures promise sustainable pathways for energy-harvesting devices. However, efficient collection before thermalization remains an obstacle for realization of their full energy generating potential. Addressing this challenge requires detailed understanding of physical processes from plasmon excitation in metal to their collection in a molecule or a semiconductor, where atomistic theoretical investigation may be particularly beneficial. Unfortunately, first-principles theoretical modeling of these processes is extremely costly, limiting the analysis to systems with a few 100s of atoms. Recent advances in machine learned interatomic potentials suggest that dynamics can be accelerated with surrogate models which replace the full solution of the Schroedinger Equation. Here, we modify an existing neural network, Hierarchically Interacting Particle Neural Network (HIP-NN), to predict plasmon dynamics in Ag nanoparticles. We demonstrate the model's capability to accurately predict plasmon dynamics in large nanoparticles of up to 561 atoms not present in the training dataset. More importantly, with machine learning models we gain a speed-up of about 200 times as compared with the rt-TDDFT calculations when predicting important physical quantities such as dynamic dipole moments in Ag55 and about 4000 times for extended nanoparticles that are 10 times larger. This underscores the promise of future machine learning accelerated electron/nuclear dynamics simulations for understanding fundamental properties of plasmon-driven hot carrier devices.
Modeling the evolution of representative dislocation structures under high thermo-mechanical conditions during Additive Manufacturing of Alloys
Creators: name: Sudmanns, Markus
name: Iliopoulos, Athanasios P.
name: Birnbaum, Andrew J.
name: Michopoulos, John G.
name: El-Awady, Jaafar A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Mesoscale simulations of discrete defects in metals provide an ideal framework to investigate the micro-scale mechanisms governing the plastic deformation under high thermal and mechanical loading conditions. To bridge size and time-scale while limiting computational effort, typically the concept of representative volume elements (RVEs) is employed. This approach considers the microstructure evolution in a volume that is representative of the overall material behavior. However, in settings with complex thermal and mechanical loading histories careful consideration of the impact of modeling constraints in terms of time scale and simulation domain on predicted results is required. We address the representation of heterogeneous dislocation structure formation in simulation volumes using the example of residual stress formation during cool-down of laser powder-bed fusion (LPBF) of AISI 316L stainless steel. This is achieved by a series of large-scale three-dimensional discrete dislocation dynamics (DDD) simulations assisted by thermo-mechanical finite element modeling of the LPBF process. Our results show that insufficient size of periodic simulation domains can result in dislocation patterns that reflect the boundaries of the primary cell. More pronounced dislocation interaction observed for larger domains highlight the significance of simulation domain constraints for predicting mechanical properties. We formulate criteria that characterize representative volume elements by capturing the conformity of the dislocation structure to the bulk material. This work provides a basis for future investigations of heterogeneous microstructure formation in mesoscale simulations of bulk material behavior.
Theory of Josephson current on a lattice model of grain boundary in $d$-wave superconductors
Creators: name: Sakamori, Takashi
name: Kashiwaya, Satoshi
name: Yano, Rikizo
name: Tanaka, Yukio
name: Hatano, Takafumi
name: Yada, Keiji
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Identifying the origins of suppression of the critical current at grain boundaries of high-critical-temperature superconductors, such as cuprates and iron-based superconductors, is a crucial issue to be solved for future applications with polycrystalline materials. Although the dominant factor of current suppression might arise during material fabrication and/or processing, investigating it due to an internal phase change of the pair potential is an important issue in understanding the threshold of the critical current. In this paper, we study the Josephson current on a symmetric [001]-tilt grain boundary (GB) of a $d$-wave superconductor on a lattice model. In addition to the suppression of the maximum Josephson current associated with the internal phase change of the $d$-wave pair potential which has been predicted in continuum models, we find a unique phase interference effect due to folding of the Fermi surface in the lattice model. In particular, the resultant maximum Josephson current at low-tilting-angle regions tends to be suppressed more than that in preexisting theories. Because similar suppressions of the critical current at GBs have been reported in several experimental works, the present model can serve as a guide to clarify the complicated transport mechanism in GBs.
Study on the global minimum and $H\toγγ$ in the Dirac scotogenic model
Creators: name: Hundi, Raghavendra Srikanth
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We have analyzed the vacuum structure of the Dirac scotogenic model, whose scalar sector consists of two complex Higgs doublets and a real singlet field. In this model, the standard model like Higgs doublet acquires non-zero vacuum expectation value (VEV), whereas, the other two fields acquire zero VEVs. This pattern of VEVs constitute a minimum, which is the desired vacuum of the model. After analyzing the scalar potential of this model, we have found that other vacua are also possible in this model. We have shown that plenty of parameter space exist where the desired vacuum of this model is the global minimum. We have studied the implications of scalar sector of this model on the observable quantity of signal strength of Higgs to diphoton decay. After evaluating this quantity, we have found that the current experimental values of this quantity can be fitted in this model. Lastly, we have studied on the possibility of making any of the additional scalar fields of this model as a candidate for dark matter.
description: 42 pages, 1 figure, 7 tables; added Sec. 8 and more phenomenological discussions; published in Phys. Rev. D
Construction of minimizing travelling waves for the Gross-Pitaevskii equation on $\mathbb{R} \times \mathbb{T}$
Creators: name: de Laire, André
name: Gravejat, Philippe
name: Smets, Didier
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q55, 35J20, 35C07, 37K05, 35C08, 35A01, 37K40

description: As a sequel to our previous analysis in [9] arXiv:2202.09411 on the Gross-Pitaevskii equation on the product space $\mathbb{R} \times \mathbb{T}$, we construct a branch of finite energy travelling waves as minimizers of the Ginzburg-Landau energy at fixed momentum. We deduce that minimizers are precisely the planar dark solitons when the length of the transverse direction is less than a critical value, and that they are genuinely two-dimensional solutions otherwise. The proof of the existence of minimizers is based on the compactness of minimizing sequences, relying on a new symmetrization argument that is well-suited to the periodic setting.
Newtonian Cosmology with a Quantum Bounce
Creators: name: Bargueño, Pedro
name: Bravo-Medina, Sergio
name: Nowakowski, Marek
name: Batic, Davide
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It has been known for some time that the cosmological Friedmann equation deduced from General Relativity can be also obtained within the Newtonian framework under certain assumptions. We use this result together with quantum corrections to the Newtonian potentials to derive a set a of quantum corrected Friedmann equations. We examine the behavior of the solutions of these modified cosmological equations paying special attention to the sign of the quantum corrections. We find different quantum effects crucially depending on this sign. One such a solution displays a qualitative resemblance to other quantum models like Loop Quantum Gravity or non-commutative geometry.
RANG: Reconstructing reproducible R computational environments
Creators: name: Chan, Chung-hong
name: Schoch, David
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation (stat.CO)
subject: Mathematical Software (cs.MS)
subject: FOS: Computer and information sciences

description: A complete declarative description of the computational environment is often missing when researchers share their materials. Without such description, software obsolescence and missing system components can jeopardize computational reproducibility in the future, even when data and computer code are available. The R package rang is a complete solution for generating the declarative description for other researchers to automatically reconstruct the computational environment at a specific time point. The reconstruction process, based on Docker, has been tested for R code as old as 2001. The declarative description generated by rang satisfies the definition of a reproducible research compendium and can be shared as such. In this contribution, we show how rang can be used to make otherwise unexecutable code, spanning from fields such as computational social science and bioinformatics, executable again. We also provide instructions on how to use rang to construct reproducible and shareable research compendia of current research. The package is currently available from CRAN (https://cran.r-project.org/web/packages/rang/index.html) and GitHub (https://github.com/chainsawriot/rang).
Leadership Capacity and Work Environment Among Nurse Managers in aTertiary Hospital in the Philippines
Creators: name: Huet, Ana Liza O.
Publisher: name: Zenodo
Year: 2023
Subjects: Leadership Capacity , work environment, nurse managers

description: Background. Aside from doing direct bedside care, nurses play a crucial role in planning and implementing health promotion activities, leading health-related organizations, and even educating future experts in health and sciences. With all these roles, one of the definitive roles of nurses is to ensure patient safety and to promote well-being of the population. Objectives. The study aimed to determine the relationship of the leadership capacity and work environment among nurses in a tertiary hospital in the Philippines. Methods. The study utilized descriptive correlational design to determine the leadership capacity of nurse managers to create and sustain a positive work environment for their staff nurses in a national university based tertiary government hospital. Pertinent data was collected using leadership capacity questionnaire and the American Association of Critical-Care Nurses (AACN) Healthy Work Environment Assessment Tool (HWEAT) to describe leadership capacity and work environment, respectively. Spearman rank correlation was used to correlate the two test variables. Test scores were interpreted using the AACN Healthy Work Assessment Guidelines. Results. Results showed an average overall score of 4.63 and 4.36 for leadership capacity and work environment, respectively. It was also observed that all domains and overall scores for leadership capacity and work environment had a statistically significant relationship and moderate positive correlation. However, statistical analysis of the relationship between leadership capacity and demographic profile and between work environment and demographic profile had no significant relationship. Conclusion and Recommendations The study showed excellent leadership capacity and work environment scores among the nurse managers in a national university based tertiary hospital in the Philippines. This is consistent with the current literature. However, the non-relationship between demographic characteristics and the test variables may be attributed to response bias presented using Likert scales. The study suggests further and continuing studies to produce more evidence that will help nurses and nurse managers in developing good leadership capacity and an excellent working environment.
Triple and Quadruple Black Holes in the ASTRID Simulation at $z \sim 2$
Creators: name: Hoffman, Calvin
name: Chen, Nianyi
name: Di Matteo, Tiziana
name: Ni, Yueying
name: Bird, Simeon
name: Croft, Rupert
name: Loeb, Abraham
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use the ASTRID cosmological hydrodynamic simulation to investigate the properties and evolution of triple and quadruple Massive Black Hole (MBH) systems at $z = 2-3$. Only a handful of MBH tuple systems have been detected to date. In ASTRID, we find $4\%$ of the $M_{\rm BH}>10^7\,M_\odot$ are in tuples with $Δr_{\rm max} < 200\,{\rm kpc}$. The tuple systems span a range of separations with the majority of the observable AGN systems at $Δr \sim 50-100$ kpc. They include some of the most massive BHs (up to $10^{10} \,M_\odot$) but with at least one of the components of $M_{\rm BH} \sim 10^7 \,M_\odot$. Tuples' host galaxies are typically massive with $M_* \sim 10^{10-11} \,M_\odot$. We find that $>10\%$ massive halos with $M_{\rm halo} > 10^{13} M_\odot$ host MBH tuples. Following the subsequent interactions between MBHs in tuples, we found that in $\sim 5\%$ of the triplets all three MBHs merge within a Gyr, and $15\%$ go through one merger. As a by-product of the complex multi-galaxy interaction of these systems, we also find that up to $\sim 5\%$ of tuples lead to runaway MBHs. In ASTRID, virtually all of the ultramassive black holes ($>10^{10} \,M_\odot $) have undergone a triple quasar phase while for BHs with $M_{\rm BH} \sim 10^9 \,M_\odot$ this fraction drops to $50\%$.
description: 10 pages, 9 figures; comments welcome
Summability of joint cumulants of nonindependent lattice fields
Creators: name: Lukkarinen, Jani
name: Marcozzi, Matteo
name: Nota, Alessia
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60G60, 60H35, 60G10, 35Q55

description: We consider two nonindependent random fields $ψ$ and $ϕ$ defined on a countable set $Z$. For instance, $Z={\mathbb Z}^d$ or $Z={\mathbb Z}^d\times I$, where $I$ denotes a finite set of possible "internal degrees of freedom" such as spin. We prove that, if the cumulants of both $ψ$ and $ϕ$ are $\ell_1$-clustering up to order $2 n$, then all joint cumulants between $ψ$ and $ϕ$ are $\ell_2$-summable up to order $n$, in the precise sense described in the text. We also provide explicit estimates in terms of the related $\ell_1$-clustering norms, and derive a weighted $\ell_2$-summation property of the joint cumulants if the fields are merely $\ell_2$-clustering. One immediate application of the results is given by a stochastic process $ψ_t(x)$ whose state is $\ell_1$-clustering at any time $t$: then the above estimates can be applied with $ψ=ψ_t$ and $ϕ=ψ_0$ and we obtain uniform in $t$ estimates for the summability of time-correlations of the field. The above clustering assumption is obviously satisfied by any $\ell_1$-clustering stationary state of the process, and our original motivation for the control of the summability of time-correlations comes from a quest for a rigorous control of the Green-Kubo correlation function in such a system. A key role in the proof is played by the properties of non-Gaussian Wick polynomials and their connection to cumulants.
description: 14 pages
Fast Bayesian Record Linkage for Streaming Data Contexts
Creators: name: Taylor, Ian
name: Kaplan, Andee
name: Betancourt, Brenda
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation (stat.CO)
subject: FOS: Computer and information sciences

description: Record linkage is the task of combining records from multiple files which refer to overlapping sets of entities when there is no unique identifying field. In streaming record linkage, files arrive sequentially in time and estimates of links are updated after the arrival of each file. This problem arises in settings such as longitudinal surveys, electronic health records, and online events databases, among others. The challenge in streaming record linkage is to efficiently update parameter estimates as new data arrive. We approach the problem from a Bayesian perspective with estimates calculated from posterior samples of parameters and present methods for updating link estimates after the arrival of a new file that are faster than fitting a joint model with each new data file. In this paper, we generalize a two-file Bayesian Fellegi-Sunter model to the multi-file case and propose two methods to perform streaming updates. We examine the effect of prior distribution on the resulting linkage accuracy as well as the computational trade-offs between the methods when compared to a Gibbs sampler through simulated and real-world survey panel data. We achieve near-equivalent posterior inference at a small fraction of the compute time. Supplemental materials for this article are available online.
description: 41 pages, 6 figures, 4 tables. (Main: 31 pages, 4 figures, 3 tables. Supplement: 10 pages, 2 figures, 1 table.) Submitted to Journal of Computational and Graphical Statistics; changes in response to JCGS minor revisions, corrected typos, improved clarity in Section 2.4, removed Section 2.4.3
Diatomic molecule in a strong infrared laser field: level-shifts and bond-length change due to laser-dressed Morse potential
Creators: name: Varró, Sándor
name: Hack, Szabolcs
name: Paragi, Gábor
name: Földi, Péter
name: Barna, Imre F.
name: Czirják, Attila
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We present a general mathematical procedure to handle interactions described by a Morse potential in the presence of a strong harmonic excitation. We account for permanent and field-induced terms and their gradients in the dipole moment function, and we derive analytic formulae for the bond-length change and for the shifted energy eigenvalues of the vibrations, by using the Kramers-Henneberger frame. We apply these results to the important cases of $\mathrm{H}_{2}$ and $\mathrm{LiH}$, driven by a near- or mid-infrared laser in the $10^{13}$ $\mathrm{ W/cm^2}$ intensity range.
Operad bimodules, and composition products on Andre-Quillen filtrations of algebras
Creators: name: Kuhn, Nicholas J.
name: Pereira, Luis A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 5P43 (primary), 18D50, 18G55, 55P48 (secondary)

description: If O is a reduced operad in symmetric spectra, an O-algebra I can be viewed as analogous to the augmentation ideal of an augmented algebra. Implicit in the literature on Topological Andre-Quillen homology is that such an I admits a canonical (and homotopically meaningful) decreasing O-algebra filtration I > I^2 > I^3 > ... satisfying various nice properties analogous to powers of an ideal in a ring. In this paper, we are explicit about these constructions. With R a commutative S-algebra, we study derived versions of the circle product M o_O I, where M is an O-bimodule, and I is an O-algebra in R-modules. Letting M run through a decreasing O-bimodule filtration of O itself then yields the augmentation ideal filtration as above. The composition structure of the operad induces algebra maps from (I^i)^j to I^{ij}, fitting nicely with previously studied structure. As a formal consequence, an O-algebra map from I to J^d induces compatible maps from I^n to J^{dn}, for all n. This is an essential tool in the first author's study of Hurewicz maps for infinite loop spaces, and its utility is illustrated here with a lifting theorem.
description: 21 pages