cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Probing anharmonic phonons by quantum correlators: A path integral approach
Creators: name: Morresi, Tommaso
name: Paulatto, Lorenzo
name: Vuilleumier, Rodolphe
name: Casula, Michele
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We devise an efficient scheme to determine vibrational properties from Path Integral Molecular Dynamics (PIMD) simulations. The method is based on zero-time Kubo-transformed correlation functions and captures the anharmonicity of the potential due to both temperature and quantum effects. Using analytical derivations and numerical calculations on toy-model potentials, we show that two different estimators built upon PIMD correlation functions fully characterize the phonon spectra and the anharmonicity strength. The first estimator is associated with force-force quantum correlators and gives access to the fundamental frequencies and thermodynamic properties of the quantum system. The second one is instead connected to displacement-displacement correlators and probes the lowest-energy phonon excitations with high accuracy. We also prove that the use of generalized eigenvalue equations, in place of the standard normal mode equations, leads to a significant speed-up in the PIMD phonon calculations, both in terms of faster convergence rate and smaller time-step bias. Within this framework, using ab initio PIMD simulations, we compute phonon dispersions of diamond and of the high-pressure I41/amd phase of atomic hydrogen. We find that, in the latter case, the anharmonicity is stronger than previously estimated and yields a sizeable red-shift in the vibrational spectrum of atomic hydrogen.
COREnext 3rd Newsletter
Creators: name: AUSTRALO
Publisher: name: Zenodo
Year: 2024

description: COREnext Newsletter, packed with updates on recent activities, publications, and our new white paper, is out now! COREnext is leading the way to a safe digital future by embedding native security measures across all layers of our systems, ensuring trustworthiness in everything from self-driving cars to privacy protection.Highlights in this issue include:✅ Celebrating our first year of digital innovation in Europe.✅ COREnext spotted at EuCNC & 6G Summit 2024, with presentations by Fredrik Tillman (Ericsson) and Zulaicha Parastuty (Infineon Technologies).✅ Release of our White Paper: "Trustworthiness – The Key to Europe’s Digital Future."✅ Insightful articles on cybersecurity, trustworthiness, and vulnerabilities in today's digital worlds.
Secondary Baryon Asymmetry in pi(+-)p Collisions
Creators: name: Arakelyan, G. H.
name: Merino, C.
name: Shabelski, Yu. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The process of secondary baryon production in pi(+-)p collisions at high energies in the central and forward fragmentation regions is considered in the framework of the Quark-Gluon String Model. The contribution of the string-junction mechanism to the baryon production is analysed. The results of numerical calculations are in reasonable agreement with the experimental data on the Lambda/bar(Lambda) and p/bar(p)$ asymmetries.
description: Contribution to the Proceedings of QCD@Work 2007, International Workshop on Quantum Chromodynamics, Theory and Experiment, Martina Franca-Valle d'Itria, Italy, June 16-20, 2007 (6 pages and 4 figures)
Electronic structure of heavily-doped graphene: the role of foreign atom states
Creators: name: Calandra, Matteo
name: Mauri, Francesco
Publisher: name: arXiv
Year: 2007
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: Using density functional theory calculations we investigate the electronic structure of graphene doped by deposition of foreign atoms. We demonstrate that, as the charge transfer to the graphene layer increases, the band structure of the pristine graphene sheet is substantially affected. This is particularly relevant when Ca atoms are deposed on graphene at CaC$_{6}$ stoichiometry. Similarly to what happens in superconducting graphite intercalated compounds, a Ca bands occurs at the Fermi level. Its hybridization with the C states generates a strong non-linearity in one of the $π^{*}$ bands below the Fermi level, at energies comparable to the graphene E$_{2g}$ phonon frequency. This strong non-linearity, and not manybody effects as previously proposed, explains the large and anisotropic values of the apparent electron-phonon coupling measured in angular resolved photoemission.
description: 4 pages, 2 figures, see also M. Calandra and F. Mauri,arXiv:0707.1467
Triangulated categories without models
Creators: name: Muro, Fernando
name: Schwede, Stefan
name: Strickland, Neil
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 18E30, 55P42

description: We exhibit examples of triangulated categories which are neither the stable category of a Frobenius category nor a full triangulated subcategory of the homotopy category of a stable model category. Even more drastically, our examples do not admit any non-trivial exact functors to or from these algebraic respectively topological triangulated categories.
description: 10 pages
title: Рыночные инструменты управления государственным долгом субъектов Российской Федерации
title: Market Instruments for Public Debt Management of Subjects of the Russian Federation
Creators: name: Аркадьева, Ольга Геннадьевна
name: Березина, Наталия Вячеславовна
name: Аркадьев, Михаил Владиславович
name: Чупракова, Ксения Николаевна
Publisher: name: Издательский центр СурГУ
Year: 2021

description: Целью исследования является оценка облигаций субъектов РФ как рыночного инструмента заимствований. При этом предметом исследования стали факторы, определяющие тенденции развития рыночной составляющей государственного долга субъектов в РФ. Задачи исследования: изучение предпосылок сокращения роли рыночных инструментов в управлении государственным долгом субъектов РФ, сопоставление тенденций развития субфедерального долга РФ с международным опытом, а также определение перспектив дальнейшего использования региональных облигаций.
В результате анализа государственного долга субъектов РФ в сопоставлении с мировым опытом установлено, что ориентиры управления государственным долгом субъектов РФ, установленные на федеральном уровне, объективные экономические предпосылки регионального развития, специфика механизма денежно-кредитного регулирования в РФ и самого финансового рынка РФ способствуют снижению роли региональных облигаций как рыночного инструмента заимствований. Перспективы развития данного инструмента могут заключаться в проработке механизмов целевых заимствований, установлении четкой взаимосвязи осуществляемых заимствований с потребностями развития региона и спросом на конкретные инструменты пула потенциальных инвесторов.
description: The purpose of the study is to assess the bonds of subjects of the Russian Federation as a market instrument of borrowings. The object of the study is factors that identify trends to develop a market part of the public debt of subjects of the Russian Federation. The objectives of the study are the following: to analyze preconditions for reduction of the market instruments role in the public debt management of subjects of the Russian Federation, to compare development trends of subfederal debt of the Russian Federation with international practice and to establish prospects of further use of the regional bonds.
As a result of the comparative analysis of the public debt of subjects of the Russian Federation and international practice, the study identifies factors that assist in reduction of the regional bonds role as a market instrument of borrowings. The above mentioned include management guidelines for the public debt of subjects of the Russian Federation imposed at the federal level, objective economic preconditions for the regional development, specifics of the monetary management mechanism in the Russian Federation and the financial market itself. The prospects of the development of such an instrument may consist of thorough development of target borrowings mechanisms, implementation of a clear correlation between borrowed assets and need of the region development and demand for particular instruments in potential investors’ pool.
Quantum many-body states and Green functions of nonequilibrium electron-magnon systems: Localized spin operators vs. their mapping to Holstein-Primakoff bosons
Creators: name: Bajpai, Utkarsh
name: Suresh, Abhin
name: Nikolic, Branislav K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The operators of localized spins within a magnetic material commute at different sites of its lattice and anticommute on the same site, so they are neither fermionic nor bosonic operators. Thus, to construct diagrammatic many-body perturbation theory, the spin operators are usually mapped to the bosonic ones with Holstein-Primakoff (HP) transformation being the most widely used in magnonics and spintronics literature. However, to make calculations tractable, the square root of operators in the HP transformation is expanded into a Taylor series truncated to some low order. This poses a question on the range of validity of truncated HP transformation when describing nonequilibrium dynamics of localized spins interacting with each other or with conduction electron spins. Here we apply exact diagonalization techniques to Hamiltonian of fermions (i.e., electrons) interacting with HP bosons vs. Hamiltonian of fermions interacting with the original localized spin operators in order to compare their many-body states and one-particle equilibrium or nonequilibrium Green functions. The Hamiltonian of fermions interacting with HP bosons gives incorrect ground state and electronic spectral function, unless large number of terms are retained in truncated HP transformation. Furthermore, tracking nonequilibrium dynamics of localized spins over longer time intervals requires progressively larger number of terms in truncated HP transformation. Finally, we show that recently proposed [M. Vogl et al., Phys. Rev. Research 2, 043243 (2020); J. König et al., SciPost Phys. 10, 007 (2021)] resummed HP transformation resolves the trouble with truncated HP transformation, while allowing us to derive an exact (manifestly Hermitian) Hamiltonian consisting of finite and fixed number of boson-boson and electron-boson interacting terms.
description: 23 pages, 10 figures
One line isn't enough...
Creators: name: Jones, Daniella
Publisher: name: F1000 Research Limited
Year: 2021

description: From COVID-19, to Cancer, to Alzheimer’s disease, big data continues to provide unparalleled understanding into determinants of health in older age.
 Latent Growth Curve Models (LGCMs) can be employed in R for prediction and forecasting; however, several implications exist with LGCMs which make it challenging to reliably comment on determinants of the ageing process. This presentation discusses potential implications of MLM in R for studying cognitive decline trajectories over a 10-year period, and whether additional modelling techniques can be adopted to improve data projections.
title: Europe at War
Creators: name: Cannizzaro, Enzo
name: Rasi, Aurora
Publisher: name: European Papers (www.europeanpapers.eu)
Year: 2022
Subjects: subject: aggression
subject: supplying of arms
subject: Common Foreign and Security Policy (CFSP)
subject: European Peace Facility
subject: jus cogens
subject: collective self-defence

description: European Papers - A Journal on Law and Integration, 2021 6(3), 1523-1525
description: For the very first time, on the 28 February 2022 the European Union decided to supply lethal military equipment to a belligerent State, namely Ukraine, who is facing a Russian aggression. From the international point of view, this decision may change the EU role in the international arena. It may be qualified as an action of collective self-defence. At the same time, the action of the EU can be regarded as the implementation of the obligation, binding upon States and international organisations, to cooperate to bring to an end through lawful means a violation of a peremptory norm, such as the prohibition of the use of force.
Quantum magnetism of iron-based ladders: Blocks, spirals, and spin flux
Creators: name: Środa, Maksymilian
name: Dagotto, Elbio
name: Herbrych, Jacek
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by increasing experimental evidence of exotic magnetism in low-dimensional iron-based materials, we present a comprehensive theoretical analysis of magnetic states of the multiorbital Hubbard ladder in the orbital-selective Mott phase (OSMP). The model we used is relevant for iron-based compounds of the AFe$_2$X$_3$ family (where A${}={}$Cs, Rb, Ba, K are alkali metals and X${}={}$S, Se are chalcogenides). To reduce computational effort, and obtain almost exact numerical results in the ladder geometry, we utilize a low-energy description of the Hubbard model in the OSMP - the generalized Kondo-Heisenberg Hamiltonian. Our main result is the doping vs interaction magnetic phase diagram. We reproduce the experimental findings on the AFe$_2$X$_3$ materials, especially the exotic block magnetism of BaFe$_2$Se$_3$ (antiferromagnetically coupled $2\times 2$ ferromagnetic islands of the $\uparrow\uparrow\downarrow\downarrow$ form). As in recent studies of the chain geometry, we also unveil block magnetism beyond the $2 \times 2$ pattern (with block sizes varying as a function of the electron doping) and also an interaction-induced frustrated block-spiral state (a spiral order of rigidly rotating ferromagnetic islands). Moreover, we predict new phases beyond the one-dimensional system: a robust regime of phase separation close to half-filling, incommensurate antiferromagnetism for weak interaction, and a quantum spin-flux phase of staggered plaquette spin currents at intermediate doping. Finally, exploiting the bonding/antibonding band occupations, we provide an intuitive physical picture giving insight into the structure of the phase diagram.
Inertial Lévy flights in bounded domains
Creators: name: Capała, Karol
name: Dybiec, Bartłomiej
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The escape from a given domain is one of the fundamental problems in statistical physics and the theory of stochastic processes. Here, we explore properties of the escape of an inertial particle driven by Lévy noise from a bounded domain, restricted by two absorbing boundaries.Presence of two absorbing boundaries assures that the escape process can be characterized by the finite mean first passage time. The detailed analysis of escape kinetics shows that properties of the mean first passage time for the integrated Ornstein--Uhlenbeck process driven by Lévy noise are closely related to properties of the integrated Lévy motions which, in turn, are close to properties of the integrated Wiener process. The extensive studies of the mean first passage time were complemented by examination of the escape velocity and energy along with their sensitivity to initial conditions.
description: 10 pages
title: Интеллектуальная цифровая платформа взаимодействия линейных и проектных подразделений университета
title: Intelligent Digital Platform for Interaction between Linear and Project Departments of the University
Creators: name: Безуевская, Валерия Александровна
name: Грошев, Александр Романович
Publisher: name: Издательский центр СурГУ
Year: 2021

description: В статье рассматриваются вопросы изменения системы управления университетами. Изложены проблемы сочетания традиционных – иерархических (линейных) – и проектных схем управления. Выдвинута гипотеза о том, что инструменты шеринг-экономики могут использоваться при организации взаимодействия проектных и линейных подразделений университета. Сформулированы предложения по содержанию интеллектуальной цифровой платформы и основным ее функциям.
description: The article analyzes issues of changes in the management system of universities. The problems of combining traditional – hierarchical (linear) – and project management schemes are presented. A hypothesis is put forward: instruments of sharing economy can be used in organizing interactions between project and linear departments of the university. The proposals have been made on the content of intelligent digital platform and its main functions.
Noninvasively improving the orbit-response matrix while continuously correcting the orbit
Creators: name: Ziemann, Ingvar
name: Ziemann, Volker
Publisher: name: arXiv
Year: 2021
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: Based on continuously recorded beam positions and corrector excitations from, for example, a closed-orbit feedback system we describe an algorithm that continuously updates an estimate of the orbit response matrix. The speed of convergence can be increased by adding very small perturbations, so-called dither, to the corrector excitations. Estimates for the rate of convergence and the asymptotically achievable accuracies are provided.
Dependence of exciton transition energy of single-walled carbon nanotubes on surrounding dielectric materials
Creators: name: Miyauchi, Yuhei
name: Saito, Riichiro
name: Sato, Kentaro
name: Ohno, Yutaka
name: Iwasaki, Shinya
name: Mizutani, Takashi
name: Jiang, Jie
name: Maruyama, Shigeo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We theoretically investigate the dependence of exciton transition energies on dielectric constant of surrounding materials. We make a simple model for the relation between dielectric constant of environment and a static dielectric constant describing the effects of electrons in core states, $σ$ bonds and surrounding materials. Although the model is very simple, calculated results well reproduce experimental transition energy dependence on dielectric constant of various surrounding materials.
description: 5pages, 4 figures
Mpemba effect and phase transitions in the adiabatic cooling of water before freezing
Creators: name: Esposito, S.
name: De Risi, R.
name: Somma, L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: An accurate experimental investigation on the Mpemba effect (that is, the freezing of initially hot water before cold one) is carried out, showing that in the adiabatic cooling of water a relevant role is played by supercooling as well as by phase transitions taking place at 6 +/- 1 oC, 3.5 +/- 0.5 oC and 1.3 +/- 0.6 oC, respectively. The last transition, occurring with a non negligible probability of 0.21, has not been detected earlier. Supported by the experimental results achieved, a thorough theoretical analysis of supercooling and such phase transitions, which are interpreted in terms of different ordering of clusters of molecules in water, is given.
description: revtex, 4 pages, 2 figures
Energetics and Kinetics Requirements for Organic Solar Cells to 2 Break the 20% Power Conversion Efficiency Barrier
Creators: name: Sandberg, Oskar J
name: Armin, Ardalan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The thermodynamic limit for the efficiency of solar cells is predominantly defined by the energy bandgap of the used semiconductor. In case of organic solar cells both energetics and kinetics of three different species play role: excitons, charge transfer states and charge separated states. In this work, we clarify the effect of the relative energetics and kinetics of these species on the recombination and generation dynamics. Making use of detailed balance, we develop an analytical framework describing how the intricate interplay between the different species influence the photocurrent generation, the recombination, and the open-circuit voltage in organic solar cells. Furthermore, we clarify the essential requirements for equilibrium between excitons, CT states and charge carriers to occur. Finally, we find that the photovoltaic parameters are not only determined by the relative energy level between the different states but also by the kinetic rate constants. These findings provide vital insights into the operation of state-of-art non-fullerene organic solar cells with low offsets.
Sterile neutrinos as subdominant warm dark matter
Creators: name: Palazzo, A.
name: Cumberbatch, D.
name: Slosar, A.
name: Silk, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In light of recent findings which seem to disfavor a scenario with (warm) dark matter entirely constituted of sterile neutrinos produced via the Dodelson-Widrow (DW) mechanism, we investigate the constraints attainable for this mechanism by relaxing the usual hypothesis that the relic neutrino abundance must necessarily account for all of the dark matter. We first study how to reinterpret the limits attainable from X-ray non-detection and Lyman-alpha forest measurements in the case that sterile neutrinos constitute only a fraction fs of the total amount of dark matter. Then, assuming that sterile neutrinos are generated in the early universe solely through the DW mechanism, we show how the X-ray and Lyman-alpha results jointly constrain the mass-mixing parameters governing their production. Furthermore, we show how the same data allow us to set a robust upper limit fs < 0.7 at the 2 sigma level, rejecting the case of dominant dark matter (fs = 1) at the ~ 3 sigma level.
description: Minor changes; added references; version accepted for publication in Phys. Rev. D
Endangered Languages are not Low-Resourced!
Creators: name: Hämäläinen, Mika
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: The term low-resourced has been tossed around in the field of natural language processing to a degree that almost any language that is not English can be called "low-resourced"; sometimes even just for the sake of making a mundane or mediocre paper appear more interesting and insightful. In a field where English is a synonym for language and low-resourced is a synonym for anything not English, calling endangered languages low-resourced is a bit of an overstatement. In this paper, I inspect the relation of the endangered with the low-resourced from my own experiences.
description: In Multilingual Facilitation (2021)
The orbit and nature of the semi-detached stellar companion of Sgr A* super-massive blackhole
Creators: name: Leibowitz, Elia
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In three previous papers I showed that the series of the midpoints of the times of all the X-ray flares of Sgr A* that have been detected so far harbor a statistical trend termed pacemaker regularity. This means that X-ray flares are detected more frequently around time points that are a subset of a periodic grid on the time axis of period P_X=0.1032 day=149 minutes. The series of the times of detection of the peaks of near IR (NIR) flares of the object are also regulated by a pacemaker with a period of P_IR=0.028 day=41 minutes. Here, I show that the series of the midpoints of the times of recorded NIR flares are also regulated by a pacemaker of the period P_IRM=0.039 day=56 minutes. The two pacemakers found in the previous papers were interpreted as signals of a star that revolves around the black hole of Sgr A* in orbit with a mean radius of ~3.2 Schwarzschild radii of the black hole, here corrected to ~3.13. The finding of the period of the third pacemaker is consistent with the suggested revolving star model. Here, I present the specific orbit of the star as well as a plausible description of its sidereal rotation. The model also implies that the star has an unusual internal structure. I show that the discovery of the GRAVITY collaboration of the motion of hotspots at distances from the black hole that are of the order of very few Schwarzschild radii of it may well be understood within the context of the revolving star model.
description: ApJ, printed version
Effects of atomic interactions on Quantum Accelerator Modes
Creators: name: Rebuzzini, Laura
name: Artuso, Roberto
name: Fishman, Shmuel
name: Guarneri, Italo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the influence of the inclusion of interatomic interactions on the delta-kicked accelerator model. Our analysis concerns in particular quantum accelerator modes, namely quantum ballistic transport near quantal resonances. The atomic interaction is modelled by a Gross-Pitaevskii cubic nonlinearity, and we address both attractive (focusing) and repulsive (defocusing) cases. The most remarkable effect is enhancement or damping of the accelerator modes, depending on the sign of the nonlinear parameter. We provide arguments showing that the effect persists beyond mean-field description, and lies within the experimentally accessible parameter range.
description: 4 pages, 6 figures
Evidence that a novel type of satellite wake might exist in Saturn's E ring
Creators: name: Hedman, M. M.
name: Young, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Saturn's E ring consists of micron-sized particles launched from Enceladus by that moon's geological activity. A variety of small-scale structures in the E-ring's brightness have been attributed to tendrils of material recently launched from Enceladus. However, one of these features occurs at a location where Enceladus' gravitational perturbations should concentrate background E-ring particles into structures known as satellite wakes. While satellite wakes have been observed previously in ring material drifting past other moons, these E-ring structures would be the first examples of wakes involving particles following horseshoe orbits near Enceladus' orbit. The predicted intensity of these wake signatures are particularly sensitive to the fraction E-ring particles' on orbits with low eccentricities and semi-major axes just outside of Enceladus' orbit, and so detailed analyses of these and other small-scale E-ring features should place strong constraints on the orbital properties and evolution of E-ring particles.
description: 18 pages, 10 figures, accepted for publication in PSJ, Revised to fix small errors found in proofs
Conditional independence for pretext task selection in Self-supervised speech representation learning
Creators: name: Zaiem, Salah
name: Parcollet, Titouan
name: Essid, Slim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Through solving pretext tasks, self-supervised learning (SSL) leverages unlabeled data to extract useful latent representations replacing traditional input features in the downstream task. A common pretext task consists in pretraining a SSL model on pseudo-labels derived from the original signal. This technique is particularly relevant for speech data where various meaningful signal processing features may serve as pseudo-labels. However, the process of selecting pseudo-labels, for speech or other types of data, remains mostly unexplored and currently relies on observing the results on the final downstream task. Nevertheless, this methodology is not sustainable at scale due to substantial computational (hence carbon) costs. Thus, this paper introduces a practical and theoretical framework to select relevant pseudo-labels with respect to a given downstream task. More precisely, we propose a functional estimator of the pseudo-label utility grounded in the conditional independence theory, which does not require any training. The experiments conducted on speaker recognition and automatic speech recognition validate our estimator, showing a significant correlation between the performance observed on the downstream task and the utility estimates obtained with our approach, facilitating the prospection of relevant pseudo-labels for self-supervised speech representation learning.
description: 5 pages, Accepted for presentation at Interspeech2021
How far is it to a sudden future singularity of pressure?
Creators: name: Dabrowski, Mariusz P.
name: Denkiewicz, Tomasz
name: Hendry, Martin A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss the constraints coming from current observations of type Ia supernovae on cosmological models which allow sudden future singularities of pressure (with the scale factor and the energy density regular). We show that such a sudden singularity may happen in the very near future (e.g. within ten million years) and its prediction at the present moment of cosmic evolution cannot be distinguished, with current observational data, from the prediction given by the standard quintessence scenario of future evolution. Fortunately, sudden future singularities are characterized by a momentary peak of infinite tidal forces only; there is no geodesic incompletness which means that the evolution of the universe may eventually be continued throughout until another ``more serious'' singularity such as Big-Crunch or Big-Rip.
description: REVTEX4, 4 pages, 2 figures, references changed
title: Региональный ресурсный центр повышения финансовой грамотности населения как ядро формирования экосистемы финансового просвещения
title: Regional Resource Center for Improving Financial Literacy of the Population as the Core for Developing Financial Education Ecosystem
Creators: name: Косенок, Сергей Михайлович
Publisher: name: Издательский центр СурГУ
Year: 2021

description: Статья посвящена описанию потенциала дополнительного профессионального образования в сфере повышения финансовой грамотности населения. Показана необходимость выстраивания экосистемы финансового просвещения в регионе, названы ее составляющие. Ядром такой системы в Ханты-Мансийском автономном округе – Югре может стать Региональный ресурсный центр повышения финансовой грамотности, сформированный в Сургутском государственном университете.
Обоснованием необходимости формирования экосистемы стали результаты анкетирования педагогов образовательных организаций, прошедших курсы повышения квалификации в Региональном ресурсном центре повышения финансовой грамотности, открытом на базе Сургутского государственного университета, данные отчетов о деятельности этого центра, а также данные мониторингов Банка России и Национального агентства финансовых исследований.
description: The article is devoted to the description of the potential of supplementary vocational education in the field of improving financial literacy of the population. The need to develop a financial education ecosystem in the region is presented, its components are identified. The Regional Resource Center for Improving Financial Literacy established at the Surgut State University can be the core for such system in the Khanty-Mansi Autonomous Okrug – Ugra. The need to develop the ecosystem is substantiated by the results of the survey of teachers in the educational institutions, who took upgrading courses in the Regional Resource Center for Improving Financial Literacy founded in the Surgut State University, as well as by the data of the center activity reports and the data of the monitoring of the Bank of Russia and the National Agency for Financial Studies.
Polaritonic characteristics of insulator and superfluid phases in a coupled-cavity array
Creators: name: Irish, E. K.
name: Ogden, C. D.
name: Kim, M. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recent studies of quantum phase transitions in coupled atom-cavity arrays have focused on the similarities between such systems and the Bose-Hubbard model. However, the bipartite nature of the atom-cavity systems that make up the array introduces some differences. In order to examine the unique features of the coupled-cavity system, the behavior of a simple two-site model is studied over a wide range of parameters. Four regions are identified, in which the ground state of the system may be classified as either a polaritonic insulator, a photonic superfluid, an atomic insulator, or a polaritonic superfluid.
description: 7 pages, 9 figures, 1 table, REVTeX 4; published version
MOESM4 of Immune-related gene signature for predicting the prognosis of head and neck squamous cell carcinoma
Creators: name: She, Yangyang
name: Kong, Xiangbo
name: Ge, Yaping
name: Yin, Ping
name: Liu, Zhiyong
name: Chen, Jieyu
name: Gao, Feng
name: Fang, Silian
Publisher: name: figshare
Year: 2020
Subjects: subject: Space Science
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Mathematical Sciences not elsewhere classified
subject: Developmental Biology
subject: Hematology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 4: Table S2. Univariate and multivariate analyses of IRGs, clinical and pathologic factors of patients in the validation cohort.
title: Psychische Belastungen bei Müllwerkern – Konsequenzen für die Beratungstätigkeit
Creators: name: Dehe, Kerstin
Publisher: name: Universität Kassel
Year: 2021
Subjects: subject: Müllwerker
subject: dirty work
subject: psychische Belastungen
subject: Gefährdungsbeurteilung
subject: teilnehmende Beobachtung
subject: garbage collector
subject: psychological stress
subject: risk assessment
subject: participating observation
subject: 150
subject: 300
subject: Müllwerker
subject: Psychische Belastung
subject: Gefährdungsanalyse
subject: Teilnehmende Beobachtung

description: Gefördert im Rahmen des Projekts DEAL
Generalizing circles over algebraic extensions
Creators: name: Recio, Tomas
name: Sendra, J. Rafael
name: Tabera, Luis Felipe
name: Villarino, Carlos
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14H99, 14-04

description: This paper deals with a family of spatial rational curves that were introduced by Andradas, Recio and Sendra, under the name of hypercircles, as an algorithmic cornerstone tool in the context of improving the rational parametrization (simplifying the coefficients of the rational functions, when possible) of algebraic varieties. A real circle can be defined as the image of the real axis under a Moebius transformation in the complex field. Likewise, and roughly speaking, a hypercircle can be defined as the image of a line ("the ${\mathbb{K}}$-axis") in a $n$-degree finite algebraic extension $\mathbb{K}(α)\thickapprox\mathbb{K}^n$ under the transformation $\frac{at+b}{ct+d}:\mathbb{K}(α)\to\mathbb{K}(α)$. The aim of this article is to extend, to the case of hypercircles, some of the specific properties of circles. We show that hypercircles are precisely, via $\mathbb{K}$-projective transformations, the rational normal curve of a suitable degree. We also obtain a complete description of the points at infinity of these curves (generalizing the cyclic structure at infinity of circles). We characterize hypercircles as those curves of degree equal to the dimension of the ambient affine space and with infinitely many ${\mathbb{K}}$-rational points, passing through these points at infinity. Moreover, we give explicit formulae for the parametrization and implicitation of hypercircles. Besides the intrinsic interest of this very special family of curves, the understanding of its properties has a direct application to the simplification of parametrizations problem, as shown in the last section.
description: 31 pages, 1 figure
Hysteresis and re-entrant melting of a self-organized system of classical particles confined in a parabolic trap
Creators: name: Munarin, F. F.
name: Nelissen, K.
name: Ferreira, W. P.
name: Farias, G. A.
name: Peeters, F. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: A self-organized system composed of classical particles confined in a two-dimensional parabolic trap and interacting through a potential with a short-range attractive part and long-range repulsive part is studied as function of temperature. The influence of the competition between the short-range attractive part of the inter-particle potential and its long-range repulsive part on the melting temperature is studied. Different behaviors of the melting temperature are found depending on the screening length ($κ$) and the strength ($B$) of the attractive part of the inter-particle potential. A re-entrant behavior and a thermal induced phase transition is observed in a small region of ($κ,B$)-space. A structural hysteresis effect is observed as a function of temperature and physically understood as due to the presence of a potential barrier between different configurations of the system.
description: 8 pages, 6 figures
Perturbation Spectra and Renormalization-Group Techniques in Double-Field Inflation and Quantum Gravity Cosmology
Creators: name: Anselmi, Damiano
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study primordial cosmology with two scalar fields that participate in inflation at the same time, by coupling quantum gravity (i.e., the theory $R+R^{2}+C^{2}$ with the fakeon prescription/projection for $C^{2}$) to a scalar field with a quadratic potential. We show that there exists a perturbative regime that can be described by an asymptotically de Sitter, cosmic RG flow in two couplings. Since the two scalar degrees of freedom mix in nontrivial ways, the adiabatic and isocurvature perturbations are not RG invariant on superhorizon scales. It is possible to identify the correct perturbations by using RG invariance as a guiding principle. We work out the resulting power spectra of the tensor and scalar perturbations to the NNLL and NLL orders, respectively. An unexpected consequence of RG invariance is that the theory remains predictive. Indeed, the scalar mixing affects only the subleading corrections, so the predictions of quantum gravity with single-field inflation are confirmed to the leading order.
description: 44 pages; JCAP
Polarization anisotropy in the optical properties of silicon ellipsoids
Creators: name: Trani, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A new real space quantum mechanical approach with local field effects included is applied to the calculation of the optical properties of silicon nanocrystals. Silicon ellipsoids are studied and the role of surface polarization is discussed in details. In particular, surface polarization is shown to be responsible for a strong optical anisotropy in silicon ellipsoids, much more pronounced with respect to the case in which only quantum confinement effects are considered. The static dielectric constant and the absorption spectra are calculated, showing that the perpendicular and parallel components have a very different dependence on the ellipsoid aspect ratio. Then, a comparison with the classical dielectric model is performed, showing that the model only works for large and regular structures, but it fails for thin elongated ellipsoids.
description: 5 pages, 4 figures, International Conference on NANO-Structures Self-Assembling
Disorder effect on the Friedel oscillations in a one-dimensional Mott insulator
Creators: name: Weiss, Yuval
name: Goldstein, Moshe
name: Berkovits, Richard
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The Friedel oscillations resulting from coupling a quantum dot to one edge of a disordered one-dimensional wire in the Mott insulator regime, are calculated numerically using the DMRG method. By investigating the influence of the disorder on the Friedel oscillations decay we find that the effect of disorder is reduced by increasing the interaction strength. This behavior is opposite to the recently reported influence of disorder in the Anderson insulator regime, where disorder led to a stronger decay of the Friedel oscillations.
description: 5 pages, 5 figures
Failed attempt to escape from the quantum pigeon conundrum
Creators: name: Aharonov, Yakir
name: Bagchi, Shrobona
name: Dressel, Justin
name: Reznik, Gregory
name: Ridley, Michael
name: Vaidman, Lev
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A recent criticism by Kunstatter et al. [Phys. Lett. A 384, 126686 (2020)] of a quantum setup violating the pigeon counting principle [Aharonov et al. PNAS 113, 532 (2016)] is refuted. The quantum nature of the violation of the pigeonhole principle with pre- and postselection is clarified.
description: to be published in Physics Letters A
Description of the Scenario Machine
Creators: name: Lipunov, V. M.
name: Postnov, K. A.
name: Prokhorov, M. E.
name: Bogomazov, A. I.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present here an updated description of the "Scenario Machine" code. This tool is used to carry out a population synthesis of binary stars. Previous version of the description can be found at http://xray.sai.msu.ru/~mystery//articles/review/contents.html
description: 32 pages, 3 figures. Corrected typos
Why do some intermediate polars show soft X-ray emission? A survey of XMM-Newton spectra
Creators: name: Evans, P. A.
name: Hellier, Coel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We make a systematic analysis of the XMM-Newton X-ray spectra of intermediate polars (IPs) and find that, contrary to the traditional picture, most show a soft blackbody component. We compare the results with those from AM Her stars and deduce that the blackbody emission arises from reprocessing of hard X-rays, rather than from the blobby accretion sometimes seen in AM Hers. Whether an IP shows a blackbody component appears to depend primarily on geometric factors: a blackbody is not seen in those that have accretion footprints that are always obscured by accretion curtains or are only visible when foreshortened on the white-dwarf limb. Thus we argue against previous suggestions that the blackbody emission characterises a separate sub-group of IPs which are more akin to AM Hers, and develop a unified picture of the blackbody emission in these stars.
description: 9 pages, 6 figures. Accepted for publication in ApJ
Unexpected Short-Period Variability in Dwarf Carbon Stars from the Zwicky Transient Facility
Creators: name: Roulston, Benjamin R.
name: Green, Paul J.
name: Toonen, Silvia
name: Hermes, J. J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Dwarf carbon (dC) stars, main sequence stars showing carbon molecular bands, are enriched by mass transfer from a previous asymptotic-giant-branch (AGB) companion, which has since evolved to a white dwarf. While previous studies have found radial-velocity variations for large samples of dCs, there are still relatively few dC orbital periods in the literature and no dC eclipsing binaries have yet been found. Here, we analyze photometric light curves from DR5 of the Zwicky Transient Facility for a sample of 944 dC stars. From these light curves, we identify 34 periodically variable dC stars. Remarkably, of the periodic dCs, 82\% have periods less than two days. We also provide spectroscopic follow-up for four of these periodic systems, measuring radial velocity variations in three of them. Short-period dCs are almost certainly post-common-envelope binary systems, since the periodicity is most likely related to the orbital period, with tidally locked rotation and photometric modulation on the dC either from spots or from ellipsoidal variations. We discuss evolutionary scenarios that these binaries may have taken to accrete sufficient C-rich material while avoiding truncation of the thermally pulsing AGB phase needed to provide such material in the first place. We compare these dCs to common-envelope models to show that dC stars probably cannot accrete enough C-rich material during the common-envelope phase, suggesting another mechanism like wind-Roche lobe overflow is necessary. The periodic dCs in this paper represent a prime sample for spectroscopic follow-up and for comparison to future models of wind-Roche lobe overflow mass transfer.
description: 23 pages, 5 figures, 5 tables, accepted to ApJ
Quasi-isometries Between Tubular Groups
Creators: name: Cashen, Christopher H
Publisher: name: arXiv
Year: 2007
Subjects: subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 20F65

description: We give a method of constructing maps between tubular groups inductively according to a set of strategies. This map will be a quasi-isometry exactly when the set of strategies is consistent. Conversely, if there exists a quasi-isometry between tubular groups, then there is a consistent set of strategies for them. There is an algorithm that will in finite time either produce a consistent set of strategies or decide that such a set does not exist. Consequently, this algorithm decides whether or not the groups are quasi-isometric.
description: 44 pages, 11 figures. PDFLaTeX. Improved exposition and added some auxiliary material to make the paper more self contained, per referee's comments
Gutzwiller description of non-magnetic Mott insulators: a dimer lattice model
Creators: name: Fabrizio, Michele
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We introduce a novel extension of the Gutzwiller variational wavefunction able to deal with insulators that escape any mean-field like description, as for instance non-magnetic insulators. As an application, we study the Mott transition from a paramagnetic metal into a non-magnetic Peierls, or valence-bond, Mott insulator. We analyze this model by means of our Gutzwiller wavefunction analytically in the limit of large coordination lattices, where we find that: (1) the Mott transition is first order; (2) the Peierls gap is large in the Mott insulator, although it is mainly contributed by the electron repulsion; (3) singlet-superconductivity arises around the transition.
description: 15 pages, 9 figures