cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Riemann curvature of a boosted spacetime geometry
Creators: name: Battista, Emmanuele
name: Esposito, Giampiero
name: Scudellaro, Paolo
name: Tramontano, Francesco
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature through Dirac's delta distribution and its derivatives is numerically evaluated for this class of spacetimes. Eventually, the analysis of the Kretschmann invariant and the geodesic equation show that the spacetime possesses a scalar curvature singularity within a 3-sphere and it is possible to define what we here call boosted horizon, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. This seems to suggest that boosted geometries are ruled by a sort of antigravity effect since all geodesics seem to refuse to enter the boosted horizon, even though their initial conditions are aimed at driving the particles towards the boosted horizon.
description: 33 pages, 8 figures. In the new version, a section and new references have been added, and the presentation has been amended and improved
Dynamic Flows on Curved Space Generated by Labeled Data
Creators: name: Hua, Xinru
name: Nguyen, Truyen
name: Le, Tam
name: Blanchet, Jose
name: Nguyen, Viet Anh
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The scarcity of labeled data is a long-standing challenge for many machine learning tasks. We propose our gradient flow method to leverage the existing dataset (i.e., source) to generate new samples that are close to the dataset of interest (i.e., target). We lift both datasets to the space of probability distributions on the feature-Gaussian manifold, and then develop a gradient flow method that minimizes the maximum mean discrepancy loss. To perform the gradient flow of distributions on the curved feature-Gaussian space, we unravel the Riemannian structure of the space and compute explicitly the Riemannian gradient of the loss function induced by the optimal transport metric. For practical applications, we also propose a discretized flow, and provide conditional results guaranteeing the global convergence of the flow to the optimum. We illustrate the results of our proposed gradient flow method on several real-world datasets and show our method can improve the accuracy of classification models in transfer learning settings.
title: Transport and coherent backscattering of Bose-Einstein condensates in mesoscopic systems
Creators: name: Hartung, Michael
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Bose-Einstein-Kondensation , Schwache Lokalisation , Transportprozess , Nichtlineares Phänomen , Unordnung , Mesoskopisches System , Quantentransport , kohärente Rückstreuung , quantum transport , coherent backscattering
subject: 530 Physik
subject: 05.60.Gg;

description: We numerically study time-dependent quantum transport of an interacting Bose-Einstein condensate based on the Gross-Pitaevskii equation in a two-dimensional correlated disorder potential. The scattering- and transport mean-free-path is numerically calculated and compared with a diagrammatic approach. Furthermore we introduce the phenomenon of coherent backscattering in the context of Bose-Einstein condensates. In the limit of a vanishing atom-atom interaction, a sharp cone in the angle-resolved density of the scattered matter wave is observed, arising from constructive interference between amplitudes propagating along reversed scattering paths. Weak interaction transforms this coherent backscattering peak into a pronounced dip, indicating destructive instead of constructive interference. This agrees with results obtained from a diagrammatic theory of weak localization in the presence of nonlinearity. For intermediate interaction strength we observe intrinsic time-dependent dynamic, which leads to a suppression of coherent backscattering.
description: Wir untersuchen mit numerischen Methoden den zeit-abhängigen Quantentransport eines Wechselwirkenden Bose-Einstein Kondensats auf Basis der Gross-Pitaevskii Gleichung in einem zwei-dimensionalen korrelierten Unordnungspotential. Die mittlere freie Streu- und Transportweglänge wird numerisch berechnet und mit einer diagrammatischen Methode verglichen. Desweiteren führen wir das Phänomen der kohärenten Rückstreuung im Kontext von Bose-Einstein Kondensaten ein. Im Grenzfall einer verschwindend kleinen Atom-Atom Wechselwirkung wird ein spitzer Kegel in der winkelaufgelösten Dichte der zurückgestreuten Materiewelle beobachtet, der durch konstruktive Interferenz zwischen zeitumgekehrten Streupfaden entsteht. Schwache Wechselwirkung führt zu einer Inversion des kohärenten Rückstreukegels, das auf destruktive statt konstrukive Interferenz zurückzuführen ist. Dies ist im Einklang mit Ergebnissen aus einer diagrammatischen Theorie für schwache Lokalisierung in Anwesenheit einer Nichtlinearität. Bei moderater Stärke der Nichtlinearität finden wir einen Übergang zu intrinsisch zeitabhängiger Dynamik, die zu einer Unterdrückung der kohärenten Rückstreuung führt.
Alberto Azevedo, Alceu Amoroso Lima (Tristão de Athayde) no Dia de Portugal e das Comunidades Portuguesas, Ed. do Autor, Braga 1993, 476 pp., 190X125.
Creators: name: Arieiro, José
Publisher: name: Theologica
Year: 1994

description: Theologica, v. 29 n. 2 (1994): Santuários marianos | Braga e Viana do Castelo
Volume Conductor: Interactive Visibility Management for Crowded Volumes
Creators: name: Lesar, Žiga
name: Alharbi, Ruwayda
name: Bohak, Ciril
name: Strnad, Ondřej
name: Heinzl, Christoph
name: Marolt, Matija
name: Viola, Ivan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: We present a novel smart visibility system for visualizing crowded volumetric data containing many object instances. The presented approach allows users to form groups of objects through membership predicates and to individually control the visibility of the instances in each group. Unlike previous smart visibility approaches, our approach controls the visibility on a per-instance basis and decides which instances are displayed or hidden based on the membership predicates and the current view. Thus, cluttered and dense volumes that are notoriously difficult to explore effectively are automatically sparsified so that the essential information is extracted and presented to the user. The proposed system is generic and can be easily integrated into existing volume rendering applications and applied to many different domains. We demonstrate the use of the volume conductor for visualizing fiber-reinforced polymers and intracellular organelle structures.
description: 12 pages, 9 figures
Inflation with moderately sharp features in the speed of sound: GSR and in-in formalism for power spectrum and bispectrum
Creators: name: Achucarro, Ana
name: Atal, Vicente
name: Hu, Bin
name: Ortiz, Pablo
name: Torrado, Jesus
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We continue the study of mild transient reductions in the speed of sound of the adiabatic mode during inflation, of their effect on the primordial power spectrum and bispectrum, and of their detectability in the Cosmic Microwave Background (CMB). We focus on the regime of \emph{moderately sharp} mild reductions in the speed of sound during uninterrupted slow-roll inflation, a theoretically well motivated and self-consistent regime that admits an effective single-field description. The signatures on the power spectrum and bispectrum were previously computed using a slow-roll Fourier transform (SRFT) approximation, and here we compare it with generalized slow-roll (GSR) and in-in methods, for which we derive new formulas that account for moderately sharp features. The agreement between them is excellent, and also with the power spectrum obtained from the numerical solution to the equation of motion. We show that, in this regime, the SRFT approximation correctly captures with simplicity the effect of higher derivatives of the speed of sound in the mode equation, and makes manifest the correlations between power spectrum and bispectrum features. In a previous paper we reported hints of these correlations in the Planck data and here we perform several consistency checks and further analyses of the best fits, such as polarization and local significance at different angular scales. For the data analysis, we show the excellent agreement between the CLASS and CAMB Boltzmann codes. Our results confirm that the theoretical framework is consistent, and they suggest that the predicted correlations are robust enough to be searched for in CMB and Large Scale Structure (LSS) surveys.
description: Matches journal version
On the complexity of finding set repairs for data-graphs
Creators: name: Abriola, Sergio
name: Cifuentes, Santiago
name: Martínez, María Vanina
name: Pardal, Nina
name: Pin, Edwin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Databases (cs.DB)
subject: Artificial Intelligence (cs.AI)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: H.2; I.2

description: In the deeply interconnected world we live in, pieces of information link domains all around us. As graph databases embrace effectively relationships among data and allow processing and querying these connections efficiently, they are rapidly becoming a popular platform for storage that supports a wide range of domains and applications. As in the relational case, it is expected that data preserves a set of integrity constraints that define the semantic structure of the world it represents. When a database does not satisfy its integrity constraints, a possible approach is to search for a 'similar' database that does satisfy the constraints, also known as a repair. In this work, we study the problem of computing subset and superset repairs for graph databases with data values using a notion of consistency based on a set of Reg-GXPath expressions as integrity constraints. We show that for positive fragments of Reg-GXPath these problems admit a polynomial-time algorithm, while the full expressive power of the language renders them intractable.
description: 35 pages , including Appendix
The Non-Axisymmetric Influence: Radius and Angle-Dependent Trends in a Barred Galaxy
Creators: name: Filion, Carrie
name: McClure, Rachel L.
name: Weinberg, Martin D.
name: D'Onghia, Elena
name: Daniel, Kathryne J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Many disc galaxies host galactic bars, which exert time-dependent, non-axisymmetric forces that can alter the orbits of stars. There should be both angle and radius-dependence in the resulting radial rearrangement of stars ('radial mixing') due to a bar; we present here novel results and trends through analysis of the joint impact of these factors. We use an N-body simulation to investigate the changes in the radial locations of star particles in a disc after a bar forms by quantifying the change in orbital radii in a series of annuli at different times post bar-formation. We find that the bar induces both azimuth angle- and radius- dependent trends in the median distance that stars have travelled to enter a given annulus. Angle-dependent trends are present at all radii we consider, and the radius-dependent trends roughly divide the disc into three 'zones'. In the inner zone, stars generally originated at larger radii and their orbits evolved inwards. Stars in the outer zone likely originated at smaller radii and their orbits evolved outwards. In the intermediate zone, there is no net inwards or outwards evolution of orbits. We adopt a simple toy model of a radius-dependent initial metallicity gradient and discuss recent observational evidence for angle-dependent stellar metallicity variations in the Milky Way in the context of this model. We briefly comment on the possibility of using observed angle-dependent metallicity trends to learn about the initial metallicity gradient(s) and the radial rearrangement that occurred in the disc.
description: Published in MNRAS, updated to match final refereed version in which a discussion on external galaxies was added
Focus Point from Direct Gauge Mediation
Creators: name: Zheng, Sibo
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This paper is devoted to reconcile the tension between theoretic expectation from naturalness and the present LHC limits on superpartner mass bounds. We argue that in SUSY models of direct gauge mediation the focusing phenomenon appears, which dramatically reduces the fine tuning associated to 126 GeV Higgs boson. This type of model is highly predictive in mass spectrum, with multi-TeV third generation, $A_t$ term of order 1 TeV, gluino mass above LHC mass bound, and light neutralinos and charginos beneath 1 TeV.
description: 5 pages, journal version, discussion about gluino mass added
AA. VV., Documentação Critica de Fátima. I; Interrogatórios aos Videntes - 1917, Santuário de Fátima, 1992, 464 pp., 235X185.
Creators: name: Arieiro, José
Publisher: name: Theologica
Year: 1994

description: Theologica, v. 29 n. 2 (1994): Santuários marianos | Braga e Viana do Castelo
koopmans: an open-source package for accurately and efficiently predicting spectral properties with Koopmans functionals
Creators: name: Linscott, Edward
name: Colonna, Nicola
name: De Gennaro, Riccardo
name: Nguyen, Ngoc Linh
name: Borghi, Giovanni
name: Ferretti, Andrea
name: Dabo, Ismaila
name: Marzari, Nicola
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Over the past decade we have developed Koopmans functionals, a computationally efficient approach for predicting spectral properties with an orbital-density-dependent functional framework. These functionals impose a generalized piecewise linearity condition to the entire electronic manifold, ensuring that orbital energies match the corresponding electron removal/addition energy differences (in contrast to semi-local DFT, where a mismatch between the two lies at the heart of the band gap problem and, more generally, the unreliability of Kohn-Sham orbital energies). This strategy has proven to be very powerful, yielding molecular orbital energies and solid-state band structures with comparable accuracy to many-body perturbation theory but at greatly reduced computational cost while preserving a functional formulation. This paper reviews the theory of Koopmans functionals, discusses the algorithms necessary for their implementation, and introduces koopmans, an open-source package that contains all of the code and workflows needed to perform Koopmans functional calculations and obtain reliable spectral properties of molecules and materials.
description: 73 pages, 4 figures, 3 tables. Document includes supporting information
Fractional Bloom boundedness and compactness of commutators
Creators: name: Hytönen, Tuomas
name: Oikari, Tuomas
name: Sinko, Jaakko
Publisher: name: arXiv
Year: 2022
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: Let $T$ be a non-degenerate Calderón-Zygmund operator and let $b:\mathbb{R}^d\to\mathbb{C}$ be locally integrable. Let $1
description: V2: 26 pages, minor revision according to referee comments, accepted for publication in Forum Mathematicum. V1:26 pages
Bowtie-free graphs have a Ramsey lift
Creators: name: Hubička, Jan
name: Nešetřil, Jaroslav
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: G.2.1; G.2.2
subject: 05C55, 05C15, 05D10, 03C35

description: A bowtie is a graph consisting of two triangles with one vertex identified. We show that the class of all (countable) graphs not containing a bowtie as a subgraph has a Ramsey lift (expansion). This solves one of the old problems in the area and it is the first non-trivial Ramsey class with a non-trivial algebraic closure.
description: 32 pages, 5 figures. Minor corrections; reformatted to elsarticle; accepted to Advances in Applied Mathematics
Deterministic, quenched and annealed parameter estimation for heterogeneous network models
Creators: name: Di Vece, Marzio
name: Garlaschelli, Diego
name: Squartini, Tiziano
Publisher: name: arXiv
Year: 2023
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Econometrics (econ.EM)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Applications (stat.AP)
subject: FOS: Physical sciences
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: At least two, different approaches to define and solve statistical models for the analysis of economic systems exist: the typical, econometric one, interpreting the Gravity Model specification as the expected link weight of an arbitrary probability distribution, and the one rooted into statistical physics, constructing maximum-entropy distributions constrained to satisfy certain network properties. In a couple of recent, companion papers they have been successfully integrated within the framework induced by the constrained minimisation of the Kullback-Leibler divergence: specifically, two, broad classes of models have been devised, i.e. the integrated and the conditional ones, defined by different, probabilistic rules to place links, load them with weights and turn them into proper, econometric prescriptions. Still, the recipes adopted by the two approaches to estimate the parameters entering into the definition of each model differ. In econometrics, a likelihood that decouples the binary and weighted parts of a model, treating a network as deterministic, is typically maximised; to restore its random character, two alternatives exist: either solving the likelihood maximisation on each configuration of the ensemble and taking the average of the parameters afterwards or taking the average of the likelihood function and maximising the latter one. The difference between these approaches lies in the order in which the operations of averaging and maximisation are taken - a difference that is reminiscent of the quenched and annealed ways of averaging out the disorder in spin glasses. The results of the present contribution, devoted to comparing these recipes in the case of continuous, conditional network models, indicate that the annealed estimation recipe represents the best alternative to the deterministic one.
description: 13 pages, 5 figures
Relating incompatibility, noncommutativity, uncertainty and Kirkwood-Dirac nonclassicality
Creators: name: De Bievre, Stephan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We provide an in-depth study of the recently introduced notion of completely incompatible observables and its links to the support uncertainty and to the Kirkwood-Dirac nonclassicality of pure quantum states. The latter notion has recently been proven central to a number of issues in quantum information theory and quantum metrology. In this last context, it was shown that a quantum advantage requires the use of Kirkwood-Dirac nonclassical states. We establish sharp bounds of very general validity that imply that the support uncertainty is an efficient Kirkwood-Dirac nonclassicality witness. When adapted to completely incompatible observables that are close to mutually unbiased ones, this bound allows us to fully characterize the Kirkwood-Dirac classical states as the eigenvectors of the two observables. We show furthermore that complete incompatibility implies several weaker notions of incompatibility, among which features a strong form of noncommutativity.
Diffusion-aware voltage source: An equivalent circuit network to resolve lithium concentration gradients in active particles
Creators: name: Zhuo, Mingzhao
name: Kirkaldy, Niall
name: Maull, Tom
name: Engstrom, Timothy
name: Offer, Gregory
name: Marinescu, Monica
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Traditional equivalent circuit models (ECMs) have difficulties in estimating battery internal states due to the lack of relevant physics, such as the lithium diffusion in active particles. Here we configure a circuit network to describe the lithium diffusion and define it as a new high-level circuit element called diffusion-aware voltage source. The circuit representation is proven equivalent to the discretized diffusion equation. The new voltage source gives the electrode potential as a function of the surface concentration and thus automatically incorporates the diffusion overpotential. We show that an ECM with the proposed diffusion-aware voltage sources (called "shell ECM") can reproduce the single particle model simulation results, making it a trustworthy easy-to-implement substitute. Furthermore, the simplest shell ECM consisting of a single diffusion-aware voltage source and a resistor is validated against experimental constant-current discharges at various rates. The diffusion-aware voltage source can be used to measure diffusivity by fitting the diffusion resistance against experimental data. The viability of the shell ECM for onboard usage is confirmed by implementation into a battery management system of WAE Technologies. By tracking the internal concentration states, the shell ECM demonstrates robustness to dynamic applied-current profiles.
description: 35 pages, 14 figures
Mixed Frobenius Structure and Local Quantum Cohomology
Creators: name: Konishi, Yukiko
name: Minabe, Satoshi
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: Primary 53D45, Secondary 14N35

description: This paper is a sequel to arXiv:1209.5550 where the notion of mixed Frobenius structure (MFS) was introduced as a generalization of the structure of a Frobenius manifold. Roughly speaking, the MFS is defined by replacing a metric of the Frobenius manifold with a filtration on the tangent bundle equipped with metrics on its graded quotients. The purpose of the current paper is to construct a MFS on the cohomology of a smooth projective variety whose multiplication is the non-equivariant limit of the quantum product twisted by a concave vector bundle. We show that such a MFS is naturally obtained as the non-equivariant limit of the Frobenius structure in the equivariant setting.
description: 18 pages, v4. title changed from "Local Quantum Cohomology and Mixed Frobenius Structure". Introduction and section 5 are revised (though results unchanged). To appear in Publications of RIMS
Resolving quantitative MRI model degeneracy with machine learning via training data distribution design
Creators: name: Guerreri, Michele
name: Epstein, Sean
name: Azadbakht, Hojjat
name: Zhang, Hui
Publisher: name: arXiv
Year: 2023
Subjects: subject: Medical Physics (physics.med-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantitative MRI (qMRI) aims to map tissue properties non-invasively via models that relate these unknown quantities to measured MRI signals. Estimating these unknowns, which has traditionally required model fitting - an often iterative procedure, can now be done with one-shot machine learning (ML) approaches. Such parameter estimation may be complicated by intrinsic qMRI signal model degeneracy: different combinations of tissue properties produce the same signal. Despite their many advantages, it remains unclear whether ML approaches can resolve this issue. Growing empirical evidence appears to suggest ML approaches remain susceptible to model degeneracy. Here we demonstrate under the right circumstances ML can address this issue. Inspired by recent works on the impact of training data distributions on ML-based parameter estimation, we propose to resolve model degeneracy by designing training data distributions. We put forward a classification of model degeneracies and identify one particular kind of degeneracies amenable to the proposed attack. The strategy is demonstrated successfully using the Revised NODDI model with standard multi-shell diffusion MRI data as an exemplar. Our results illustrate the importance of training set design which has the potential to allow accurate estimation of tissue properties with ML.
description: 13 pages, 4 figures
Fundamental Limits of Caching with Secure Delivery
Creators: name: Sengupta, Avik
name: Tandon, Ravi
name: Clancy, T. Charles
Publisher: name: arXiv
Year: 2013
Subjects: subject: Information Theory (cs.IT)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Caching is emerging as a vital tool for alleviating the severe capacity crunch in modern content-centric wireless networks. The main idea behind caching is to store parts of popular content in end-users' memory and leverage the locally stored content to reduce peak data rates. By jointly designing content placement and delivery mechanisms, recent works have shown order-wise reduction in transmission rates in contrast to traditional methods. In this work, we consider the secure caching problem with the additional goal of minimizing information leakage to an external wiretapper. The fundamental cache memory vs. transmission rate trade-off for the secure caching problem is characterized. Rather surprisingly, these results show that security can be introduced at a negligible cost, particularly for large number of files and users. It is also shown that the rate achieved by the proposed caching scheme with secure delivery is within a constant multiplicative factor from the information-theoretic optimal rate for almost all parameter values of practical interest.
Evolution of a Stratified Turbulent Cloud under Rotation
Creators: name: Li, Tianyi
name: Wan, Minping
name: Chen, Shiyi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Localized turbulence is common in geophysical flows, where the roles of rotation and stratification are paramount. In this study, we investigate the evolution of a stratified turbulent cloud under rotation. Recognizing that a turbulent cloud is composed of vortices of varying scales and shapes, we start our investigation with a single eddy using analytical solutions derived from a linearized system. Compared to an eddy under pure rotation, the stratified eddy shows the physical manifestation of a known potential vorticity mode, appearing as a static stable vortex. In addition, the expected shift from inertial waves to inertial-gravity waves is observed. In our numerical simulations of the turbulent cloud, carried out at a constant Rossby number over a range of Froude numbers, stratification causes columnar structures to deviate from vertical alignment. This deviation increases with increasing stratification, slowing the expansion rate of the cloud. The observed characteristics of these columnar structures are consistent with the predictions of linear theory, particularly in their tilt angles and vertical growth rates, suggesting a significant influence of inertial-gravity waves. Using Lagrangian particle tracking, we have identified regions where wave activity dominates over turbulence. In scenarios of milder stratification, these inertial-gravity waves are responsible for a significant energy transfer away from the turbulent cloud, a phenomenon that attenuates with increasing stratification.
Octahedral distortions in SrNbO$_3$: Unraveling the structure-property relation
Creators: name: Rosendal, Victor
name: Brito, Walber Hugo
name: Radovic, Milan
name: Chikina, Alla
name: Brandbyge, Mads
name: Pryds, Nini
name: Petersen, Dirch Hjorth
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Strontium niobate has triggered a lot of interest as a transparent conductor and as a possible realization of a correlated Dirac semi-metal. Using the lattice parameters as a tunable knob, the energy landscape of octahedral tilting was mapped using density functional theory calculations. We find that biaxial compressive strain induces tilting around the out-of-plane axis, while tensile strain induces tilting around the two in-plane axes. The two competing distorted structures for compressive strain show semi-Dirac dispersions above the Fermi level in their electronic structure. Our density functional theory calculations combined with dynamical mean field theory (DFT+DMFT) reveals that dynamical correlations downshift these semi-Dirac like cones towards the Fermi energy. More generally, our study reveals that the competition between the in-phase and out-of-phase tilting in SrNbO$_3$ provides a new degree of freedom which allows for tuning the thermoelectric and optical properties. We show how the tilt angle and mode is reflected in the behavior of the Seebeck coefficient and the plasma frequency, due to changes in the band structure.
Thomson rings in a disk
Creators: name: Cerkaski, M.
name: Nazmitdinov, R. G.
name: Puente, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We discuss the basic principles of a self-organization of a finite number of charged particles interacting via the 1/r Coulomb potential in a disk geometry. Our approach is based on the cyclic symmetry and periodicity of the Coulomb interaction between particles located on several rings. As a result, a system of equations is derived, which allows us readily to determine with a high accuracy the equilibrium configurations of a few hundreds charged particles. For $n\gtrsim 200$ we predict the formation of a hexagonal core and valence circular rings for the centered configurations.
description: 13 pages, 3 figures, 1 table. Published version with a new figure and extended discussion
Padre Martins Capela, Escritos Dispersos. Edição Comemorativa do 150. ° Aniversário do seu Nascimento, Ed. Câmara Municipal de Terras de Bouro, 1992, 488 pp., 245X180.
Creators: name: Arieiro, José
Publisher: name: Theologica
Year: 1994

description: Theologica, v. 29 n. 2 (1994): Santuários marianos | Braga e Viana do Castelo
Impact of lattice rotation on dislocation motion
Creators: name: Perreault, Brent
name: Vinals, Jorge
name: Rickman, Jeffrey M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We introduce a phenomenological theory of dislocation motion appropriate for two dimensional lattices. A coarse grained description is proposed that involves as primitive variables local lattice rotation and Burgers vector densities along distinguished slip systems of the lattice. We then use symmetry considerations to propose phenomenological equations for both defect energies and their dissipative motion. As a consequence, the model includes explicit dependences on the local state of lattice orientation, and allows for differential defect mobilities along distinguished directions. Defect densities and lattice rotation need to determined self consistently and we show specific results for both square and hexagonal lattices. Within linear response, dissipative equations of motion for the defect densities are derived which contain defect mobilities that depend nonlocally on defect distribution.
description: 28 pages, 3 figure
A geometric analysis of the impact of large but finite switching rates on vaccination evolutionary games
Creators: name: Della Marca, Rossella
name: d'Onofrio, Alberto
name: Sensi, Mattia
name: Sottile, Sara
Publisher: name: arXiv
Year: 2023
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Dynamical Systems (math.DS)
subject: FOS: Biological sciences
subject: FOS: Mathematics

description: In contemporary society, social networks accelerate decision dynamics causing a rapid switch of opinions in a number of fields, including the prevention of infectious diseases by means of vaccines. This means that opinion dynamics can nowadays be much faster than the spread of epidemics. Hence, we propose a Susceptible-Infectious-Removed epidemic model coupled with an evolutionary vaccination game embedding the public health system efforts to increase vaccine uptake. This results in a global system ``epidemic model + evolutionary game''. The epidemiological novelty of this work is that we assume that the switching to the strategy ``pro vaccine'' depends on the incidence of the disease. As a consequence of the above-mentioned accelerated decisions, the dynamics of the system acts on two different scales: a fast scale for the vaccine decisions and a slower scale for the spread of the disease. Another, and more methodological, element of novelty is that we apply Geometrical Singular Perturbation Theory (GSPT) to such a two-scale model and we then compare the geometric analysis with the Quasi-Steady-State Approximation (QSSA) approach, showing a criticality in the latter. Later, we apply the GSPT approach to the disease prevalence-based model already studied in (Della Marca and d'Onofrio, Comm Nonl Sci Num Sim, 2021) via the QSSA approach by considering medium-large values of the strategy switching parameter.
description: 26 pages, 6 figures
unarXive 2022: All arXiv Publications Pre-Processed for NLP, Including Structured Full-Text and Citation Network
Creators: name: Saier, Tarek
name: Krause, Johan
name: Färber, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: Digital Libraries (cs.DL)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Large-scale data sets on scholarly publications are the basis for a variety of bibliometric analyses and natural language processing (NLP) applications. Especially data sets derived from publication's full-text have recently gained attention. While several such data sets already exist, we see key shortcomings in terms of their domain and time coverage, citation network completeness, and representation of full-text content. To address these points, we propose a new version of the data set unarXive. We base our data processing pipeline and output format on two existing data sets, and improve on each of them. Our resulting data set comprises 1.9 M publications spanning multiple disciplines and 32 years. It furthermore has a more complete citation network than its predecessors and retains a richer representation of document structure as well as non-textual publication content such as mathematical notation. In addition to the data set, we provide ready-to-use training/test data for citation recommendation and IMRaD classification. All data and source code is publicly available at https://github.com/IllDepence/unarXive.
description: submitted to JCDL2023
Assessing the impact of Byzantine attacks on coupled phase oscillators
Creators: name: Tyloo, Melvyn
Publisher: name: arXiv
Year: 2023
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Systems and Control (eess.SY)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: For many coupled dynamical systems, the interaction is the outcome of the measurement that each unit has of the others as e.g. in modern inverter-based power grids, autonomous vehicular platoons or swarms of drones, or it is the results of physical flows. Synchronization among all the components of these systems is of primal importance to avoid failures. The overall operational state of these systems therefore crucially depends on the correct and reliable functioning of the individual elements as well as the information they transmit through the network. Here, we investigate the effect of Byzantine attacks where one unit does not behave as expected, but is controlled by an external attacker. For such attacks, we assess the impact on the global collective behavior of nonlinearly coupled phase oscillators. We relate the synchronization error induced by the input signal to the properties of the attacked node. This allows to anticipate the potential of an attacker and identify which network components to secure.
description: 9 pages, 5 figures
Quasihomogeneous free divisors with only normal crossings in codimension one
Creators: name: Liao, Xia
name: Schulze, Mathias
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 32S25 (Primary) 16W25 (Secondary)

description: We prove that any divisor as in the title must be normal crossing.
description: 14 pages, 2 figures
Maximum entropy states of collisionless positron-electron plasma in a dipole magnetic field
Creators: name: Sato, Naoki
Publisher: name: arXiv
Year: 2022
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We are developing a positron-electron plasma trap based on a dipole magnetic field generated by a levitated superconducting magnet to investigate the physics of magnetized plasmas with mass symmetry as well as antimatter components. Such laboratory magnetosphere is deemed essential for the understanding of pair plasmas in astrophysical environments, such as magnetars and blackholes, and represents a novel technology with potential applications in antimatter confinement and development of coherent gamma-ray lasers. The design of the device requires a preemptive analysis of the achievable self-organized steady states. In this study, we construct a theoretical model describing maximum entropy states of a collisionless positron-electron plasma confined by a dipole magnetic field, and demonstrate efficient confinement of both species under a wide range of physical parameters by analysing the effect of the three adiabatic invariants on the phase space distribution function. The theory is verified by numerical evaluation of spatial density, electrostatic potential, and toroidal rotation velocity for each species in correspondence of the maximum entropy state.
description: 25 pages, 7 figures
Darboux Transformation and Exact Solutions of the integrable Heisenberg ferromagnetic equation with self-consistent potentials
Creators: name: Yersultanova, Z. S.
name: Zhassybayeva, M.
name: Yesmakhanova, K.
name: Nugmanova, G.
name: Myrzakulov, R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: Integrable Heisenberg ferromagnetic equations are an important subclass of integrable systems. The M-XCIX equation is one of a generalizations of the Heisenberg ferromagnetic equation and are integrable. In this paper, the Darboux transformation of the M-XCIX equation is constructed. Using the DT, a 1-soliton solution of the M-XCIX equation is presented.
description: 10 pages, Int. J. Geom. Methods Mod. Phys., (2015)
Phenomenology of charmed mesons in the extended Linear Sigma Model
Creators: name: Eshraim, Walaa I.
name: Giacosa, Francesco
name: Rischke, Dirk H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the so-called extended linear sigma model for the case of four quark flavors. This model is based on global chiral symmetry and dilatation invariance and includes, besides scalar and pseudoscalar mesons, vector and axial-vector mesons. Most of the parameters of the model have been determined in previous work by fitting properties of mesons with three quark flavors. Only three new parameters, all related to the current charm quark mass, appear when introducing charmed mesons. Surprisingly, within the accuracy expected from our approach, the masses of open charmed mesons turn out to be in quantitative agreement with experimental data. On the other hand, with the exception of $J/ψ$, the masses of charmonia are underpredicted by about 10\%. It is remarkable that our approach correctly predicts (within errors) the mass splitting between spin-0 and spin-1 negative-parity open charm states. This indicates that, although the charm quark mass breaks chiral symmetry quite strongly explicitly, this symmetry still seems to have some influence on the properties of charmed mesons.
description: 19 pages, 1 figure, 3 tables
CoCon: A Data Set on Combined Contextualized Research Artifact Use
Creators: name: Saier, Tarek
name: Dong, Youxiang
name: Färber, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: Digital Libraries (cs.DL)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: In the wake of information overload in academia, methodologies and systems for search, recommendation, and prediction to aid researchers in identifying relevant research are actively studied and developed. Existing work, however, is limited in terms of granularity, focusing only on the level of papers or a single type of artifact, such as data sets. To enable more holistic analyses and systems dealing with academic publications and their content, we propose CoCon, a large scholarly data set reflecting the combined use of research artifacts, contextualized in academic publications' full-text. Our data set comprises 35 k artifacts (data sets, methods, models, and tasks) and 340 k publications. We additionally formalize a link prediction task for "combined research artifact use prediction" and provide code to utilize analyses of and the development of ML applications on our data. All data and code is publicly available at https://github.com/IllDepence/contextgraph.
description: submitted to JCDL2023
Whittaker Coefficients of Metaplectic Eisenstein Series
Creators: name: Brubaker, Benjamin
name: Friedberg, Solomon
Publisher: name: arXiv
Year: 2014
Subjects: subject: Number Theory (math.NT)
subject: Combinatorics (math.CO)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: Primary 11F70, Secondary 05E10, 11F68

description: We study Whittaker coefficients for maximal parabolic Eisenstein series on metaplectic covers of split reductive groups. By the theory of Eisenstein series these coefficients have meromorphic continuation and functional equation. However they are not Eulerian and the standard methods to compute them in the reductive case do not apply to covers. For "cominuscule" maximal parabolics, we give an explicit description of the coefficients as Dirichlet series whose arithmetic content is expressed in an exponential sum. The exponential sum is then shown to satisfy a twisted multiplicativity, reducing its determination to prime power contributions. These, in turn, are connected to Lusztig data for canonical bases on the dual group using a result of Kamnitzer. The exponential sum at prime powers is then evaluated for generic Lusztig data. To handle the remaining degenerate cases, the evaluation of the exponential sum appears best expressed in terms of string data for canonical bases, as shown in a detailed example in $GL_4$. Thus we demonstrate that the arithmetic part of metaplectic Whittaker coefficients is intimately connected to the relations between these two expressions for canonical bases.
description: 51 pages. To appear in GAFA
Similarity transformed equation of motion coupled cluster theory revisited: a benchmark study of valence excited states
Creators: name: Sous, J.
name: Goel, P.
name: Nooijen, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The similarity transformed equation of motion coupled cluster (STEOM-CC) method is benchmarked against CC3 and EOM-CCSDT-3 for a large test set of valence excited states of organic molecules studied by Schreiber et al. [M. Schreiber, M.R. Silva-Junior, S.P. Sauer, and W. Thiel, J. Chem. Phys. $\textbf{128}$, 134110 (2008)]. STEOM-CC is found to behave quite satisfactorily and provides significant improvement over EOM-CCSD, CASPT2 and NEVPT2 for singlet excited states, lowering standard deviations of these methods by almost a factor of 2. Triplet excited states are found to be described less accurately, however. Besides the parent version of STEOM-CC, additional variations are considered. STEOM-D includes a perturbative correction from doubly excited determinants. The novel STEOM-H ($ω$) approach presents a sophisticated technique to render the STEOM-CC transformed Hamiltonian hermitian. In STEOM-PT, the expensive CCSD step is replaced by many-body second-order perturbation theory (MBPT(2)), while extended STEOM (EXT-STEOM) provides access to doubly excited states. To study orbital invariance in STEOM, we investigate orbital rotation in the STEOM-ORB approach. Comparison of theses variations of STEOM for the large test set provides a comprehensive statistical basis to gauge the usefulness of these approaches.
description: Invited article to the Special Issue of Molecular Physics "proceedings of Molecular Quantum Mechanics 2013: electron correlation: the many-body problem at the heart of chemistry" dedicated as a Festschrift for Professor Rodney Bartlett; 49 pages, 10 figures, 11 tables
Manuel José Macário do Nascimento Clemente, Nas origens do Apostolado contemporâneo em Portugal. A Sociedade Católica (1843-1853), Col. ≪Memorabilia Christiana≫ 5, Universidade Católica Portuguesa, Braga 1993, 300 pp., 260X190, ISBN 972-8090-05-6
Creators: name: Araújo, António De
Publisher: name: Theologica
Year: 1994

description: Theologica, v. 29 n. 2 (1994): Santuários marianos | Braga e Viana do Castelo
Fourier transform for functions of bicomplex variables
Creators: name: Banerjee, Abhijit
name: Datta, Sanjib Kumar
name: Hoque, Md Azizul
Publisher: name: arXiv
Year: 2014
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: This paper examines the existence and region of convergence of Fourier transform of the functions of bicomplex variables with the help of projection on its idempotent components as auxiliary complex planes. Several basic properties of this bicomplex version of Fourier transform are examined.
description: 1 figure