cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Two white dwarfs in ultrashort binaries with detached, eclipsing, likely substellar companions detected by K2
Creators: name: Parsons, S. G.
name: Hermes, J. J.
name: Marsh, T. R.
name: Gänsicke, B. T.
name: Tremblay, P. -E.
name: Littlefair, S. P.
name: Sahman, D. I.
name: Ashley, R. P.
name: Green, M.
name: Rattanasoon, S.
name: Dhillon, V. S.
name: Burleigh, M. R.
name: Casewell, S. L.
name: Buckley, D. A. H.
name: Braker, I. P.
name: Irawati, P.
name: Dennihy, E.
name: Rodríguez-Gil, P.
name: Winget, D. E.
name: Winget, K. I.
name: Bell, K. J.
name: Kilic, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Using data from the extended Kepler mission in K2 Campaign 10 we identify two eclipsing binaries containing white dwarfs with cool companions that have extremely short orbital periods of only 71.2 min (SDSS J1205-0242, a.k.a. EPIC 201283111) and 72.5 min (SDSS J1231+0041, a.k.a. EPIC 248368963). Despite their short periods, both systems are detached with small, low-mass companions, in one case a brown dwarf, and the other case either a brown dwarf or a low-mass star. We present follow-up photometry and spectroscopy of both binaries, as well as phase-resolved spectroscopy of the brighter system, and use these data to place preliminary estimates on the physical and binary parameters. SDSS J1205-0242 is composed of a $0.39\pm0.02$M$_\odot$ helium-core white dwarf which is totally eclipsed by a $0.049\pm0.006$M$_\odot$ ($51\pm6$M$_J$) brown dwarf companion, while SDSS J1231+0041 is composed of a $0.56\pm0.07$M$_\odot$ white dwarf which is partially eclipsed by a companion of mass $\lesssim 0.095$M$_\odot$. In the case of SDSS J1205-0242 we look at the combined constraints from common-envelope evolution and brown dwarf models; the system is compatible with similar constraints from other post common-envelope binaries given the current parameter uncertainties, but has potential for future refinement.
description: Accepted for publication in MNRAS
Quantum simulation of ultrastrongly coupled bosonic modes using superconducting circuits
Creators: name: Fedortchenko, S.
name: Felicetti, S.
name: Marković, D.
name: Jezouin, S.
name: Keller, A.
name: Coudreau, T.
name: Huard, B.
name: Milman, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The ground state of a pair of ultrastrongly coupled bosonic modes is predicted to be a two-mode squeezed vacuum. However, the corresponding quantum correlations are currently unobservable in condensed matter where such a coupling can be reached, since it cannot be extracted from these systems. Here, we show that superconducting circuits can be used to perform an analog simulation of a system of two bosonic modes in regimes ranging from strong to ultrastrong coupling. More importantly, our quantum simulation setup enables us to detect output excitations that are related to the ground-state properties of the bosonic modes. We compute the emission spectra of this physical system and show that the produced state presents single- and two-mode squeezing simultaneously.
description: 8 pages, 4 figures
Hierarchy of equations to calculate the linear spectra of molecular aggregates - Time-dependent and frequency domain formulation
Creators: name: Zhang, Pan-Pan
name: Li, Zeng-Zhao
name: Eisfeld, Alexander
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In a recent publication [J. Chem. Phys. 142, 034115 (2015)] we have derived a hierarchy of coupled differential equations in time domain to calculate the linear optical properties of molecular aggregates. Here we provide details about issues concerning the numerical implementation. In addition we present the corresponding hierarchy in frequency domain.
Edition of One Prospectus
Creators: name: Keeney, Gavin
Publisher: name: Zenodo
Year: 2024
Subjects: Intellectual Property
Philosophy of Art
Political Economy
Cultural Commons

description: Edition of One (EO1) is a literary agency for the collective production of works of literary-artistic scholarship. The EO1 project follows a research PhD in Philosophy, conducted at the Postgraduate School, ZRC SAZU, Ljubljana, Slovenia (2021-2024), concerning forms of research and scholarship that go beyond current academic and art-world conventions and one step beyond Open Access protocols into an as-yet-to-be-defined realm denoted the wild blue yonder.
Valley dependent anisotropic spin splitting in silicon quantum dots
Creators: name: Ferdous, Rifat
name: Kawakami, Erika
name: Scarlino, Pasquale
name: Nowak, Michał P.
name: Ward, D. R.
name: Savage, D. E.
name: Lagally, M. G.
name: Coppersmith, S. N.
name: Friesen, Mark
name: Eriksson, Mark A.
name: Vandersypen, Lieven M. K.
name: Rahman, Rajib
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Spin qubits hosted in silicon (Si) quantum dots (QD) are attractive due to their exceptionally long coherence times and compatibility with the silicon transistor platform. To achieve electrical control of spins for qubit scalability, recent experiments have utilized gradient magnetic fields from integrated micro-magnets to produce an extrinsic coupling between spin and charge, thereby electrically driving electron spin resonance (ESR). However, spins in silicon QDs experience a complex interplay between spin, charge, and valley degrees of freedom, influenced by the atomic scale details of the confining interface. Here, we report experimental observation of a valley dependent anisotropic spin splitting in a Si QD with an integrated micro-magnet and an external magnetic field. We show by atomistic calculations that the spin-orbit interaction (SOI), which is often ignored in bulk silicon, plays a major role in the measured anisotropy. Moreover, inhomogeneities such as interface steps strongly affect the spin splittings and their valley dependence. This atomic-scale understanding of the intrinsic and extrinsic factors controlling the valley dependent spin properties is a key requirement for successful manipulation of quantum information in Si QDs.
description: 9 pages, 5 figures, supplementary (13 pages, 7 figures)
Nagid u-metsaṿeh: ʻim ḳetsat hagahot ha-Rama.z asher bo nikhlalim kol minhagim shel ha-rav
Creators: Ẓemaḥ, Jacob ben Ḥayyim, active 17th century
Publisher: name: Columbia University
Year: 2016
Subjects: Cabala

description: Manuscript in Hebrew on paper.
Strongly self-absorbing C*-dynamical systems, III
Creators: name: Szabo, Gabor
Publisher: name: arXiv
Year: 2016
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L55

description: In this paper, we accomplish two objectives. Firstly, we extend and improve some results in the theory of (semi-)strongly self-absorbing C*-dynamical systems, which was introduced and studied in previous work. In particular, this concerns the theory when restricted to the case where all the semi-strongly self-absorbing actions are assumed to be unitarily regular, which is a mild technical condition. The central result in the first part is a strengthened version of the equivariant McDuff-type theorem, where equivariant tensorial absorption can be achieved with respect to so-called very strong cocycle conjugacy. Secondly, we establish completely new results within the theory. This mainly concerns how equivariantly $\cal Z$-stable absorption can be reduced to equivariantly UHF-stable absorption with respect to a given semi-strongly self-absorbing action. Combining these abstract results with known uniqueness theorems due to Matui and Izumi-Matui, we obtain the following main result. If $G$ is a torsion-free abelian group and $\cal D$ is one of the known strongly self-absorbing C*-algebras, then strongly outer $G$-actions on $\cal D$ are unique up to (very strong) cocycle conjugacy. This is new even for $\mathbb{Z}^3$-actions on the Jiang-Su algebra.
description: 22 pages; v3 some added remarks and simplified argument in section 5
An analytic method for identifying dynamically-formed runaway stars
Creators: name: Ryu, Taeho
name: Leigh, Nathan W. C.
name: Perna, Rosalba
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this paper, we study the 3-body products (two single stars and a binary) of binary-binary (2+2) scattering interactions. This is done using a combination of analytic methods and numerical simulations of 2+2 scattering interactions, both in isolation and in a homogeneous background potential. We derive analytically a simple formula relating the angle between the velocity vectors of the two ejected single stars and the orbital separation of the remaining binary. We compare our analytic formulation to numerical scattering simulations, and illustrate that the agreement is excellent, both in isolation and in a homogeneous background potential. Our results are ideally suited for application to the GAIA database, which is expected to identify many hundred runaway stars. The analytic relation presented here has the potential to identify runaway stars formed dynamically with high confidence. Finally, by applying our method to the runaways AE Aur and $μ$ Col, we illustrate that it can be used to constrain the history of the background potential, which was denser than the presently observed density in the case of the Trapezium cluster.
description: 18 pages, 8 figures, 1 table, accepted to MNRAS
Dispersive wave propagation in disordered flexible fibers enhances stress attenuation
Creators: name: Wang, Peng
name: Pähtz, Thomas
name: Luo, Kun
name: Guo, Yu
Publisher: name: arXiv
Year: 2024
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We experimentally and computationally analyze impact-shock-induced stress wave propagation in packings of disordered flexible fibers. We find that dispersive wave propagation, associated with large stress attenuation, occurs much more prevalently in systems with larger fiber aspect ratios and moderate fiber flexibility. We trace these features to the microstructural properties of fiber contact chains and the energy-trapping abilities of deformable fibers. These findings provide new insights into physics of the shock-impacted flexible fiber packings and open the way towards an improved granular-material-based damping technology.
description: 6 pages, 6 figures
LOLA -- An Open-Source Massively Multilingual Large Language Model
Creators: name: Srivastava, Nikit
name: Kuchelev, Denis
name: Ngoli, Tatiana Moteu
name: Shetty, Kshitij
name: Röder, Michael
name: Zahera, Hamada
name: Moussallem, Diego
name: Ngomo, Axel-Cyrille Ngonga
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: This paper presents LOLA, a massively multilingual large language model trained on more than 160 languages using a sparse Mixture-of-Experts Transformer architecture. Our architectural and implementation choices address the challenge of harnessing linguistic diversity while maintaining efficiency and avoiding the common pitfalls of multilinguality. Our analysis of the evaluation results shows competitive performance in natural language generation and understanding tasks. Additionally, we demonstrate how the learned expert-routing mechanism exploits implicit phylogenetic linguistic patterns to potentially alleviate the curse of multilinguality. We provide an in-depth look at the training process, an analysis of the datasets, and a balanced exploration of the model's strengths and limitations. As an open-source model, LOLA promotes reproducibility and serves as a robust foundation for future research. Our findings enable the development of compute-efficient multilingual models with strong, scalable performance across languages.
Thermodynamics of a Schwarzschild black hole surrounded by quintessence in the generalized uncertainty principle framework
Creators: name: Sen, Soham
name: Dutta, Abhijit
name: Gangopadhyay, Sunandan
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the thermodynamics of a Schwarzschild black hole, surrounded by the quintessence energy-matter in the linear and quadratic generalized uncertainty principle framework. Considering the variance in the position to be of the order of the event horizon radius and equating the variance in the momentum to the Hawking temperature of the black hole, we substitute these variances in the deformed algebra. From there we obtained the generalized uncertainty principle-modified black hole temperature and eventually the specific heat of the black hole. Then we calculate the critical as well as the remnant mass and obtain the entropy relation. We observe that the entropy relation includes the usual leading order ``\textit{area divided by four}" term, sub-leading logarithmic term, and higher order inverse of the area corrections. Finally, calculating the energy output as a function of time, we obtain the evaporation time of the black hole. The results show the dependence of the quintessence parameter on the thermodynamic quantities in the framework of linear and quadratic generalized uncertainty principle.
description: 19 pages LATEX; OTM
Quantum dynamics of bosons in a two-ring ladder: dynamical algebra, vortex-like excitations and currents
Creators: name: Richaud, Andrea
name: Penna, Vittorio
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the quantum dynamics of the Bose-Hubbard model on a ladder formed by two rings coupled by tunneling effect. By implementing the Bogoliubov approximation scheme, we prove that, despite the presence of the inter-ring coupling term, the Hamiltonian decouples in many independent sub-Hamiltonians $\hat{H}_k$ associated to momentum-mode pairs $\pm k$. Each sub-Hamiltonian $\hat{H}_k$ is then shown to be part of a specific dynamical algebra. The properties of the latter allow us to perform the diagonalization process, to find energy spectrum, the conserved quantities of the model, and to derive the time evolution of important physical observables. We then apply this solution scheme to the simplest possible closed ladder, the double trimer. After observing that the excitations of the system are weakly-populated vortices, we explore the corresponding dynamics by varying the initial conditions and the model parameters. Finally, we show that the inter-ring tunneling determines a spectral collapse when approaching the border of the dynamical-stability region.
description: 14 pages, 9 figures
Turbulent geodynamo simulations: a leap towards Earth's core
Creators: name: Schaeffer, Nathanaël
name: Jault, Dominique
name: Nataf, Henri-Claude
name: Fournier, Alexandre
Publisher: name: arXiv
Year: 2017
Subjects: subject: Geophysics (physics.geo-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We present an attempt to reach realistic turbulent regime in direct numerical simulations of the geodynamo. We rely on a sequence of three convection-driven simulations in a rapidly rotating spherical shell. The most extreme case reaches towards the Earth's core regime by lowering viscosity (magnetic Prandtl number Pm=0.1) while maintaining vigorous convection (magnetic Reynolds number Rm>500) and rapid rotation (Ekman number E=1e-7), at the limit of what is feasible on today's supercomputers. A detailed and comprehensive analysis highlights several key features matching geomagnetic observations or dynamo theory predictions -- all present together in the same simulation -- but it also unveils interesting insights relevant for Earth's core dynamics.In this strong-field, dipole-dominated dynamo simulation, the magnetic energy is one order of magnitude larger than the kinetic energy. The spatial distribution of magnetic intensity is highly heterogeneous, and a stark dynamical contrast exists between the interior and the exterior of the tangent cylinder (the cylinder parallel to the axis of rotation that circumscribes the inner core).In the interior, the magnetic field is strongest, and is associated with a vigorous twisted polar vortex, whose dynamics may occasionally lead to the formation of a reverse polar flux patch at the surface of the shell. Furthermore, the strong magnetic field also allows accumulation of light material within the tangent cylinder, leading to stable stratification there. Torsional Alfv{é}n waves are frequently triggered in the vicinity of the tangent cylinder and propagate towards the equator.Outside the tangent cylinder, the magnetic field inhibits the growth of zonal winds and the kinetic energy is mostly non-zonal. Spatio-temporal analysis indicates that the low-frequency, non-zonal flow is quite geostrophic (columnar) and predominantly large-scale: an m=1 eddy spontaneously emerges in our most extreme simulations, without any heterogeneous boundary forcing.Our spatio-temporal analysis further reveals that (i) the low-frequency, large-scale flow is governed by a balance between Coriolis and buoyancy forces -- magnetic field and flow tend to align, minimizing the Lorentz force; (ii) the high-frequency flow obeys a balance between magnetic and Coriolis forces; (iii) the convective plumes mostly live at an intermediate scale, whose dynamics is driven by a 3-term 1 MAC balance -- involving Coriolis, Lorentz and buoyancy forces. However, small-scale (E^{1/3}) quasi-geostrophic convection is still observed in the regions of low magnetic intensity.
description: 48 pages, 28 figures, accepted for publication in GJI
Relic galaxies: where are they?
Creators: name: de Arriba, Luis Peralta
name: Quilis, Vicent
name: Trujillo, Ignacio
name: Cebrián, María
name: Balcells, Marc
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The finding that massive galaxies grow with cosmic time fired the starting gun for the search of objects which could have survived up to the present day without suffering substantial changes (neither in their structures, neither in their stellar populations). Nevertheless, and despite the community efforts, up to now only one firm candidate to be considered one of these relics is known: NGC 1277. Curiously, this galaxy is located at the centre of one of the most rich near galaxy clusters: Perseus. Is its location a matter of chance? Should relic hunters focus their search on galaxy clusters? In order to reply this question, we have performed a simultaneous and analogous analysis using simulations (Millennium I-WMAP7) and observations (New York University Value-Added Galaxy Catalogue). Our results in both frameworks agree: it is more probable to find relics in high density environments.
description: 6 pages, 4 figures. Updated to match the published version in Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society held on July 18-22, 2016, in Bilbao, Spain. S. Arribas, A. Alonso-Herrero, F. Figueras, C. Hern\'andez-Monteagudo, A. S\'anchez-Lavega, S. P\'erez-Hoyos (eds.)
Calibration of a two-phase xenon time projection chamber with a $^{37}$Ar source
Creators: name: Boulton, E. M.
name: Bernard, E.
name: Destefano, N.
name: Edwards, B. N. V.
name: Gai, M.
name: Hertel, S. A.
name: Horn, M.
name: Larsen, N. A.
name: Tennyson, B. P.
name: Wahl, C.
name: McKinsey, D. N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We calibrate a two-phase xenon detector at 0.27 keV in the charge channel and at 2.8 keV in both the light and charge channels using a $^{37}$Ar source that is directly released into the detector. We map the light and charge yields as a function of electric drift field. For the 2.8 keV peak, we calculate the Thomas-Imel box parameter for recombination and determine its dependence on drift field. For the same peak, we achieve an energy resolution, $E_σ/E_{mean}$, between 9.8% and 10.8% for 0.1 kV/cm to 2 kV/cm electric drift fields.
description: 12 pages, 7 figures
Animation of Land Cover Changes from 1990 to 2018 Using CORINE Data in Paris, France
Creators: name: Firanj Sremac, Ana
Publisher: name: Zenodo
Year: 2024
Subjects: subject: Data science
subject: CORINE land cover
subject: Satelite data
subject: Data processing

description: This animated gif showcases the dynamic changes in land cover from 1990 to 2018, created using data from the CORINE Land Cover project. The gif highlights the evolution of land use and provides a visual representation of environmental shifts over nearly three decades in Paris, France.

Data Sources:

1990: CORINE Land Cover (doi: 10.2909/c89324ef-7729-4477-9f1b-623f5f88eaa1)

2000: CORINE Land Cover (doi: 10.2909/ddacbd5e-068f-4e52-a596-d606e8de7f40)

2006: CORINE Land Cover (doi: 10.2909/08560441-2fd5-4eb9-bf4c-9ef16725726a)

2012: CORINE Land Cover (doi: 10.2909/a84ae124-c5c5-4577-8e10-511bfe55cc0d)

2018: CORINE Land Cover (doi: 10.2909/960998c1-1870-4e82-8051-6485205ebbac)

The creation of this gif was made possible through the use of several powerful R packages, namely:

terra

tmap

sf
Clouds in the atmospheres of extrasolar planets. V. The impact of CO2 ice clouds on the outer boundary of the habitable zone
Creators: name: Kitzmann, Daniel
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Clouds have a strong impact on the climate of planetary atmospheres. The potential scattering greenhouse effect of CO2 ice clouds in the atmospheres of terrestrial extrasolar planets is of particular interest because it might influence the position and thus the extension of the outer boundary of the classic habitable zone around main sequence stars. Here, the impact of CO2 ice clouds on the surface temperatures of terrestrial planets with CO2 dominated atmospheres, orbiting different types of stars is studied. Additionally, their corresponding effect on the position of the outer habitable zone boundary is evaluated. For this study, a radiative-convective atmospheric model is used the calculate the surface temperatures influenced by CO2 ice particles. The clouds are included using a parametrised cloud model. The atmospheric model includes a general discrete ordinate radiative transfer that can describe the anisotropic scattering by the cloud particles accurately. A net scattering greenhouse effect caused by CO2 clouds is only obtained in a rather limited parameter range which also strongly depends on the stellar effective temperature. For cool M-stars, CO2 clouds only provide about 6 K of additional greenhouse heating in the best case scenario. On the other hand, the surface temperature for a planet around an F-type star can be increased by 30 K if carbon dioxide clouds are present. Accordingly, the extension of the habitable zone due to clouds is quite small for late-type stars. Higher stellar effective temperatures, on the other hand, can lead to outer HZ boundaries about 0.5 au farther out than the corresponding clear-sky values.
description: Includes minor changes made during the production stage. Fixed typo in Table 1
A computational study on lens spaces isospectral on forms
Creators: name: Lauret, Emilio A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Differential Geometry (math.DG)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: 58J53

description: We make a computational study to know what kind of isospectralities among lens spaces and lens orbifolds exist considering the Hodge--Laplace operators acting on smooth $p$-forms. Several evidenced facts are proved and some others are conjectured.
Beʾer mayim ḥayim: sefer kolel u-meʾasef ḳetsat maʾamare Talmud ṿe-Halakhot ṿe-Agadot, meyusadim ʻal adane ha-Alfa Beta..ʻim perush milim zarot
Creators: Rabba, Eliyahu ben Menaḥem
Publisher: name: Columbia University
Year: 2016

description: Manuscript in Hebrew and Italian, on paper.
Deep neural networks for detection of rare events, novelties, and data augmentation in multimodal data streams
Creators: name: Nesen, Alina V
Publisher: name: Purdue University Graduate School
Year: 2022
Subjects: Knowledge representation and reasoning
Deep learning
Neural networks

description: The abundance of heterogeneous data produced and collected each day via multimodal sources may contain hidden events of interest, but in order to extract them the streams of data need to be analyzed with appropriate algorithms, so these events are presented to the end user at the right moment and at the right time. This dissertation proposes a series of algorithms that shape a comprehensive framework for situational knowledge on demand to address this problem. The framework consists of several modules and approaches, each of them is presented in a separate chapter: I begin with video data analysis in streaming video and video at rest for enhanced object detection of real-life surveillance video. For detecting the rare events of interest, I develop a semantic video analysis algorithm which uses an overlay knowledge graph and a semantical network. I show that the usage of the external knowledge for understanding the semantic analysis outperforms other techniques such as transfer learning. The semantical outliers can be used further for improving the algorithm of detecting new objects in the stream of different modalities. I extend the framework with additional modules for natural language data and apply the extended version of the semantic analysis algorithm to define the events of interest from multimodal streaming data. I present a way of combining several feature extractors which can be extended to multiple heterogeneous streams of data in order to efficiently fuse the data based on its semantical similarity, and then show how the serverless architecture of the framework outperforms conventional cloud software architecture. Besides detecting the rare and semantically incompatible events, the semantic analysis can be used for improving the neural networks performance with the data augmentation. The algorithm presented for augmenting the data with the potentially novel objects to circumvent the data drift problem uses the knowledge graph and generative adversarial networks to present the objects to augment the training datasets for supervised learning. I extend the presented framework with a pipeline for generating synthetic novelties to improve the performance of feature extractors and provide the empirical evaluation of the developed method.
A categorical approach to the maximum theorem
Creators: name: Koudenburg, Seerp Roald
Publisher: name: arXiv
Year: 2017
Subjects: subject: Category Theory (math.CT)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 49J27, 49J45, 54A05, 54B30, 54E70, 18A40, 18C20, 18D05

description: Berge's maximum theorem gives conditions ensuring the continuity of an optimised function as a parameter changes. In this paper we state and prove the maximum theorem in terms of the theory of monoidal topology and the theory of double categories. This approach allows us to generalise (the main assertion of) the maximum theorem, which is classically stated for topological spaces, to pseudotopological spaces and pretopological spaces, as well as to closure spaces, approach spaces and probabilistic approach spaces, amongst others. As a part of this we prove a generalisation of the extreme value theorem.
description: 45 pages. Minor changes in v2: this is the final preprint for publication in JPAA
Highest $\ell$-Weight Representations and Functional Relations
Creators: name: Nirov, Khazret S.
name: Razumov, Alexander V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We discuss highest $\ell$-weight representations of quantum loop algebras and the corresponding functional relations between integrability objects. In particular, we compare the prefundamental and $q$-oscillator representations of the positive Borel subalgebras of the quantum group $\mathrm{U}_q(\mathcal L(\mathfrak{sl}_{l+1}))$ for arbitrary values of $l$. Our article has partially the nature of a short review, but it also contains new results. These are the expressions for the $L$-operators, and the exact relationship between different representations, as a byproduct resulting in certain conclusions about functional relations.
Cosmic Microwave Background Mapmaking with a Messenger Field
Creators: name: Huffenberger, Kevin M.
name: Næss, Sigurd K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We apply a messenger field method to solve the linear minimum-variance mapmaking equation in the context of Cosmic Microwave Background (CMB) observations. In simulations, the method produces sky maps that converge significantly faster than those from a conjugate gradient descent algorithm with a diagonal preconditioner, even though the computational cost per iteration is similar. The messenger method recovers large scales in the map better than conjugate gradient descent, and yields a lower overall $χ^2$. In the single, pencil beam approximation, each iteration of the messenger mapmaking procedure produces an unbiased map, and the iterations become more optimal as they proceed. A variant of the method can handle differential data or perform deconvolution mapmaking. The messenger method requires no preconditioner, but a high-quality solution needs a cooling parameter to control the convergence. We study the convergence properties of this new method, and discuss how the algorithm is feasible for the large data sets of current and future CMB experiments.
description: 12 pages, 6 figures, revision includes new sections that treat differential data. Submitted to ApJ
High stability 2D electron gases formed in Si3N4/Al//KTaO3 heterostructures: synthesis and in-depth interfacial characterization
Creators: name: Martínez, E. A.
name: Lucero, A. M.
name: Cantero, E. D.
name: Biškup, N.
name: Orte, A.
name: Sánchez, E. A.
name: Romera, M.
name: Nemes, N. M.
name: Martínez, J. L.
name: Varela, M.
name: Grizzi, O.
name: Bruno, F. Y.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The two-dimensional electron gas (2DEG) found in KTaO3-based interfaces has garnered attention due to its remarkable electronic properties. In this study, we investigated the conducting system embedded at the Si3N4/Al//KTO(110) heterostructure. We demonstrate that the Al/KTO interface supports a conducting system, with the Si3N4 passivation layer acting as a barrier to oxygen diffusion, enabling ex-situ characterization. Our findings reveal that the mobility and carrier density of the system can be tuned by varying the Al layer thickness. Using scanning transmission electron microscopy, electron energy-loss spectroscopy, X-ray photoemission spectroscopy, and time-of-flight secondary ion mass spectrometry, we characterized the structural and chemical composition of the interface. We found that the Al layer fully oxidizes into AlOx, drawing oxygen from the KTaO3 substrate. The oxygen depletion zone extends 3-5 nm into the substrate and correlates to the Al thickness. Heterostructures with thicker Al layers exhibit higher carrier densities but lower mobilities, likely due to interactions with the oxygen vacancies that act as scattering centers. These findings highlight the importance of considering the effect and extent of the oxygen depletion zone when designing and modeling two-dimensional electron systems in complex oxides.
Comparison of viscoelastic finite element models for laminated glass beams
Creators: name: Zemanová, Alena
name: Zeman, Jan
name: Šejnoha, Michal
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Laminated glass elements, which consist of stiff elastic glass layers connected with a compliant viscoelastic polymer foil, exhibit geometrically non-linear and time/temperature-sensitive behavior. In computational modeling, the viscoelastic effects are often neglected or a detailed continuum formulation typically based on the volumetric-deviatoric elastic-viscoelastic split is used for the interlayer. Four layerwise beam theories are introduced in this paper, which differ in the non-linear beam formulation at the layer level (von Kármán/Reissner) and in constitutive assumptions for the interlayer (a viscoelastic solid with the time-independent bulk modulus/Poisson ratio). We perform detailed verification and validation studies at different temperatures and compare the accuracy of the selected formulation with simplified elastic solutions used in practice. We show that all the four formulations predict very similar responses. Therefore, our suggestion is to use the most straightforward formulation that combines the von Kármán model with the assumption of time-independent Poisson ratio. The simplified elastic model mostly provides a response in satisfactory agreement with full viscoelastic solutions. However, it can lead to unsafe or inaccurate predictions for rapid changes of loading. These findings provide a suitable basis for extensions towards laminated plates and glass layer fracture, owing to the modular format of layerwise theories.
description: 30 pages, 11 figures, 8 tables, 1 algorithm
Unified description of dynamics of a repulsive two-component Fermi gas
Creators: name: Grochowski, Piotr T.
name: Karpiuk, Tomasz
name: Brewczyk, Mirosław
name: Rzążewski, Kazimierz
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study a binary spin-mixture of a zero-temperature repulsively interacting $^6$Li atoms using both the atomic-orbital and the density functional approaches. The gas is initially prepared in a configuration of two magnetic domains and we determine the frequency of the spin-dipole oscillations which are emerging after the repulsive barrier, initially separating the domains, is removed. We find, in agreement with recent experiment (G. Valtolina et al., arXiv:1605.07850 (2016)), the occurrence of a ferromagnetic instability in an atomic gas while the interaction strength between different spin states is increased, after which the system becomes ferromagnetic. The ferromagnetic instability is preceded by the softening of the spin-dipole mode.
description: 5 pages, 2 figures
Quasiperiodic Floquet-Gibbs states in Rydberg atomic systems
Creators: name: Martins, Wilson S.
name: Carollo, Federico
name: Brandner, Kay
name: Lesanovsky, Igor
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Open systems that are weakly coupled to a thermal environment and driven by fast, periodically oscillating fields are commonly assumed to approach an equilibrium-like steady state with respect to a truncated Floquet-Magnus Hamiltonian. Using a general argument based on Fermi's golden rule, we show that such Floquet-Gibbs states emerge naturally in periodically modulated Rydberg atomic systems, whose lab-frame Hamiltonian is a quasiperiodic function of time. Our approach applies as long as the inherent Bohr frequencies of the system, the modulation frequency and the frequency of the driving laser, which is necessary to uphold high-lying Rydberg excitations, are well separated. To corroborate our analytical results, we analyze a realistic model of up to five interacting Rydberg atoms with periodically changing detuning. We demonstrate numerically that the second-order Floquet-Gibbs state of this system is essentially indistinguishable from the steady state of the corresponding Redfield equation if the modulation and driving frequencies are sufficiently large.
description: 8 + 5 pages, 2+1 figures. Minor changes made to the text and a figure added to the supplementary material
Thermal Inflation with Flaton Chemical Potential
Creators: name: Arai, Masato
name: Kobayashi, Yoshishige
name: Okada, Nobuchika
name: Sasaki, Shin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Thermal inflation driven by a scalar field called "flaton" is a possible scenario to solve the cosmological moduli problem. We study a model of thermal inflation with a flaton chemical potential. In the presence of the chemical potential, a negative mass squared of the flaton, which is necessary to terminate the thermal inflation, is naturally induced. We identify the allowed parameter region for the chemical potential ($μ$) and the flaton self-coupling constant to solve the cosmological moduli problem and satisfy theoretical consistencies. In general, the chemical potential is a free parameter and it can be taken to be much larger than the typical scale of soft supersymmetry breaking parameters of $\mathcal{O} (1)$ TeV. For $μ\gtrsim 10^8$ GeV, we find that the reheating temperature after the thermal inflation can be high enough for the thermal leptogenesis scenario to be operative. This is in sharp contrast to the standard thermal inflation scenario, in which the reheating temperature is quite low and a special mechanism is necessary for generating sufficient amount of baryon asymmetry in the Universe after thermal inflation.
description: 22 pages, 3 figures, appendix added, version published in Phys. Rev. D
Fermionic triplet dark matter in an $SO(10)$-inspired left right model
Creators: name: Arbeláez, Carolina
name: Hirsch, Martin
name: Restrepo, Diego
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study a left right (LR) extension of the Standard Model (SM) where the Dark Matter (DM) candidate is composed of a set of fermionic Majorana triplets. The DM is stabilized by a remnant $Z_{2}$ symmetry from the breaking of the LR group to the SM. Two simple scenarios where the DM particles plus a certain set of extra fields lead to gauge coupling unification with a low LR scale are explored. The constraints from relic density and predictions for direct detection are discussed for both scenarios. The first scenario with a $SU(2)_R$ vectorlike fermion triplet contains a DM candidate which is almost unconstrained by current direct detection experiments. The second scenario, with an additional $SU(2)_R$ triplet, opens up a scalar portal leading to direct detection constraints which are similar to collider limits for right gauge bosons. The DM parameter space consistent with phenomenological requirements can also lead to successful gauge coupling unification in a $SO(10)$ setup.
Half-metallicity versus Symmetry in Pt, Ni and Co-based Half Heusler Alloys: A First-principles Calculation
Creators: name: Baral, Madhusmita
name: Chakrabarti, Aparna
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using first principles calculations based on density functional theory, we study the geometric, electronic, and magnetic properties of Pt, Ni and Co-based half Heusler alloys, namely, Pt$BC$, Ni$BC$ and Co$BC$ ($B$ = Cr, Mn and Fe; $C$ = Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te). We calculate the formation energy of these alloys in various crystal symmetries, which include, the (face-centered) cubic $C1_{b}$ ($F\bar{4}$3m), orthorhombic ($Pnma$), as well as hexagonal ($P\bar{6}2m$ and $P6_{3}/mmc$) structures. It has been observed that out of all the 108 structures, studied here, energetically stable cubic structure is observed for only 18 materials. These alloys are primarily having either a $C$ atom or an $A$ atom with a high atomic number. We also observe that along with the alloys with $C$ atoms from group IIIA, IVA and VA -- alloys with $C$ atoms from group VIA are also found to be, by and large, energetically stable. To examine the relative stabilities of different symmetries in order to search for the respective lowest energy state for each of the above-mentioned systems, as well as to find whether a material in the ground state is half-metallic or not, we analyze the formation energy, and the electronic density of states, in detail. Based on these analyses, the possibility of existence of any {\it one-to-one relationship} between the {\it cubic symmetry} and the {\it half-metallicity} in these half Heusler alloys is probed. Subsequently, we predict about the existence of a few new {\it non-cubic} half Heusler alloys with substantially low density of states at one of the spin channels and reasonably {\it high spin polarization at the Fermi level}
Polarized Heavy Quarkonium Production in the Color Evaporation Model
Creators: name: Cheung, Vincent
name: Vogt, Ramona
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We explore polarized heavy quarkonium production using the color evaporation model at leading order. We present the polarized to total yield ratio as a function of center of mass energy and rapidity in $p+p$ collisions. At energies far above the $Q \overline Q$ production threshold, we find charmonium and bottomonium production to be longitudinally polarized ($J_z=0$). The quarkonium states are also longitudinally polarized at central rapidity, becoming transversely polarized ($J_z=\pm1$) at the most forward rapidities.
Predicting ULX demographics from geometrical beaming
Creators: name: Middleton, Matthew
name: King, Andrew
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The ultraluminous X-ray source (ULX) population is known to contain neutron stars, but the relative number of these compared to black hole primaries is unknown. Assuming classical super-critical accretion and resultant geometrical beaming, we show that the observed population ratio can be predicted from the mean masses of each family of compact objects and the relative spatial density of neutron stars to black holes. Conversely - and perhaps more importantly - given even a crude estimate for the spatial densities, an estimate of the fraction of the population containing neutron stars will begin to constrain the mean mass of black holes in ULXs.
description: 3 pages, 1 figure, accepted for publication in MNRASL, typos corrected
Learning by Doing Versus Memorization -A Perspective of Learning in The UBE Classroom.pdf
Creators: name: Inyang, Mary  Imo
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 399999
subject: Other education not elsewhere classified

description: One of the basic challenges of the Universal Basic Education (UBE) in Nigeria is the lack or near total absence of learning materials. Observed trend is emphasis on didactic method which encourages memorization. Recently, learning theories and research results reveal the achievement of better learning experiences when learners are meaningfully engaged in the learning process as against rote learning. This paper sheds some light on learning by doing as a more beneficial process of learning than memorizing. It also discusses the classroom implications of learning by doing and their expected gains for the UBE programme…
Anomalous temperature-dependent heat transport in one-dimensional momentum-conserving systems with soft-type interparticle interaction
Creators: name: Xiong, Daxing
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We here numerically investigate the heat transport behavior in a one-dimensional lattice with a soft-type (ST) anharmonic interparticle interaction. It is found that with the increase of system's temperature, while the introduction of ST anharmonicity softens phonons and decreases their velocities, this type of nonlinearity like its counterpart of hard type (HT), can still not be able to fully damp the longest wave phonons. Therefore, an anomalous temperature dependent heat transport with certain scaling properties similarly to those in the Fermi-Pasta-Ulam like systems with HT interactions can be seen. Our detailed examination from simulations well verify this temperature dependent behavior.
description: 7 pages; 10 figures
Raman scattering excitation spectroscopy in monolayer WS$_2$
Creators: name: Molas, Maciej R.
name: Nogajewski, Karol
name: Potemski, Marek
name: Babinski, Adam
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Resonant Raman scattering is investigated in monolayer WS$_2$ at low temperature with the aid of an unconventional spectroscopy technique, $i.e.$, Raman scattering excitation (RSE). The RSE spectrum is made up by sweeping the excitation energy, when the detection energy is fixed in resonance with excitonic transitions related to neutral and/or charged excitons. We demonstrate that the shape of the RSE spectrum strongly depends on a selected detection energy. The out-going resonance with the neutral exciton leads to an extremely rich RSE spectrum displaying several Raman scattering features not reported so far, while no clear effect on the associated background photoluminescence is observed. Instead, a strong enhancement of the emission due to the negatively charged exciton is apparent when the out-going photons resonate with this exciton. Presented results show that the RSE spectroscopy can be a useful technique to study electron-phonon interactions in thin layers of transition metal dichalcogenides.
description: 9 pages, 5 figures
Can charm fluctuation be a better probe to study QCD critical point?
Creators: name: Goswami, Kangkan
name: Pradhan, Kshitish Kumar
name: Sahu, Dushmanta
name: Dey, Jayanta
name: Sahoo, Raghunath
Publisher: name: arXiv
Year: 2024
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 study the diffusion properties of an interacting hadron gas and evaluate the diffusion coefficient matrix for the baryon, strange, electric, and charm quantum numbers. For the first time, this study sheds light on the charm current and estimates the diffusion matrix coefficient for the charmed states by treating them as a part of the quasi-thermalized medium. We explore the diffusion matrix coefficient as a function of temperature and center-of-mass energy. A van der Waals-like interaction is assumed between the hadrons, including attractive and repulsive interactions. The calculation of diffusion coefficients is based on relaxation time approximation to the Boltzmann transport equation. A good agreement with available model calculations is observed in the hadronic limit. To conclude the study, we discuss, with a detailed explanation, that charm fluctuation is expected to be a better tool for probing the QCD critical point.
description: Same as the published version in Phys. Rev. D