cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A unified picture of medium-induced radiation
Creators: name: Isaksen, Johannes Hamre
name: Takacs, Adam
name: Tywoniuk, Konrad
Publisher: name: arXiv
Year: 2022
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 revisit the picture of jets propagating in the quark-gluon plasma. In addition to vacuum radiation, partons scatter on the medium constituents resulting in induced emissions. Analytical approaches to including these interactions have traditionally dealt separately with multiple, soft, or rare, hard scatterings. A full description has so far only been available using numerical methods. We achieve full analytical control of the relevant scales and map out the dominant physical processes in the full phase space. To this aim, we extend existing expansion schemes for the medium-induced spectrum to the Bethe--Heitler regime. This covers the whole phase space from early to late times, and from hard splittings to emissions below the thermal scale. Based on the separation of scales, a space-time picture naturally emerges: at early times, induced emissions start to build from rare scatterings with the medium. At a later stage, induced emissions due to multiple soft scatterings result in a turbulent cascade that rapidly degrades energy down to, and including, the Bethe--Heitler regime. We quantify the impact of such an improved picture, compared to the current state-of-the-art factorization that includes only soft scatterings, by both analytical and numerical methods for the medium-induced energy distribution function. Our work serves to improve our understanding of jet quenching from small to large systems and for future upgrades of Monte Carlo generators.
description: published version, 58 pages, 11 figures, if the figures don't load properly try using a different PDF reader
Higgsino Dark Matter in High-Scale Supersymmetry
Creators: name: Nagata, Natsumi
name: Shirai, Satoshi
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study a supersymmetric (SUSY) Standard Model in which a Higgsino is light enough to be dark matter, while the other SUSY particles are much heavier than the weak scale. We carefully treat the effects of heavy SUSY particles to the Higgsino nature, especially taking into account the renormalization effects due to the large hierarchy between the Higgsino and the SUSY breaking scales. Inelastic scattering of the Higgsino dark matter with a nucleus is studied, and the constraints on the scattering by the direct detection experiments are discussed. This gives an upper limit on the new physics scale. Bounds on the dark matter-nucleon elastic scattering, the electric dipole moments, and direct production of Higgsinos, on the other hand, give a lower limit. We show the current status on the limits and discuss the future prospects.
description: 28 pages, 12 figures. Version accepted for publication in JHEP
Steering-enhanced quantum metrology using superpositions of noisy phase shifts
Creators: name: Lee, Kuan-Yi
name: Lin, Jhen-Dong
name: Miranowicz, Adam
name: Nori, Franco
name: Ku, Huan-Yu
name: Chen, Yueh-Nan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum steering is an important correlation in quantum information theory. A recent work [Nat. Commun. 12, 2410 (2021)] showed that quantum steering is also useful for quantum metrology. Here, we extend the exploration of steering-enhanced quantum metrology from single noiseless phase shifts to superpositions of noisy phase shifts. As concrete examples, we consider a control system that manipulates a target system to pass through a superposition of either dephased or depolarized phase shifts channels. We show that using such superpositions of noisy phase shifts can suppress the effects of noise and improve metrology. Furthermore, we also implemented proof-of-principle experiments for a superposition of dephased phase shifts on the IBM Quantum Experience, demonstrating a clear improvement on metrology.
description: 12 pages, 7 figures
Dynamical phenomena near a homo- or heteroclinic connection involving saddle-foci in a Hamiltonian system
Creators: name: Lerman, Lev M.
Publisher: name: Weierstrass Institute
Year: 2000
Subjects: subject: Hamiltonian
subject: saddle-focus
subject: homoclinic
subject: heteroclinic
subject: bifurcation
subject: generating function
subject: 34C37
subject: 37J45

description: The main features of the orbit behavior for a Hamiltonian system in a neighborhood of a homoclinic orbit to a saddle-focus equilibrium or of a contour made up of two saddle-foci and two heteroclinic orbits to them are presented. These features includes description of hyperbolic subsets and main bifurcations when varying a value of the Hamiltonian and parameters. The proofs of results about bifurcations are given.
Constraining the Galaxy's dark halo with RAVE stars
Creators: name: Piffl, T.
name: Binney, J.
name: McMillan, P. J.
name: Steinmetz, M.
name: Helmi, A.
name: Wyse, R. F. G.
name: Bienaymé, O.
name: Bland-Hawthorn, J.
name: Freeman, K.
name: Gibson, B.
name: Gilmore, G.
name: Grebel, E. K.
name: Kordopatis, G.
name: Navarro, J. F.
name: Parker, Q.
name: Reid, W. A.
name: Seabroke, G.
name: Siebert, A.
name: Watson, F.
name: Zwitter, T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We use the kinematics of $\sim200\,000$ giant stars that lie within $\sim 1.5$ kpc of the plane to measure the vertical profile of mass density near the Sun. We find that the dark mass contained within the isodensity surface of the dark halo that passes through the Sun ($(6\pm0.9)\times10^{10}\,\mathrm{M_\odot}$), and the surface density within $0.9$ kpc of the plane ($(69\pm10)\,\mathrm{M_\odot\,pc^{-2}}$) are almost independent of the (oblate) halo's axis ratio $q$. If the halo is spherical, 46 per cent of the radial force on the Sun is provided by baryons, and only 4.3 per cent of the Galaxy's mass is baryonic. If the halo is flattened, the baryons contribute even less strongly to the local radial force and to the Galaxy's mass. The dark-matter density at the location of the Sun is $0.0126\,q^{-0.89}\,\mathrm{M_\odot\,pc^{-3}}=0.48\,q^{-0.89}\,\mathrm{GeV\,cm^{-3}}$. When combined with other literature results we find hints for a mildly oblate dark halo with $q \simeq 0.8$. Our value for the dark mass within the solar radius is larger than that predicted by cosmological dark-matter-only simulations but in good agreement with simulations once the effects of baryonic infall are taken into account. Our mass models consist of three double-exponential discs, an oblate bulge and a Navarro-Frenk-White dark-matter halo, and we model the dynamics of the RAVE stars in the corresponding gravitational fields by finding distribution functions $f(\mathbf{J})$ that depend on three action integrals. Statistical errors are completely swamped by systematic uncertainties, the most important of which are the distance to the stars in the photometric and spectroscopic samples and the solar distance to the Galactic centre. Systematics other than the flattening of the dark halo yield overall uncertainties $\sim 15$ per cent.
description: 20 pages, 17 figures, accepted for publication in MNRAS
An FPGA-based Solution for Convolution Operation Acceleration
Creators: name: Pham, Trung Dinh
name: Bach, Bao Gia
name: Luu, Lam Trinh
name: Nguyen, Minh Dinh
name: Pham, Hai Duc
name: Anh, Khoa Bui
name: Nguyen, Xuan Quang
name: Quoc, Cuong Pham
Publisher: name: arXiv
Year: 2022
Subjects: subject: Hardware Architecture (cs.AR)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Hardware-based acceleration is an extensive attempt to facilitate many computationally-intensive mathematics operations. This paper proposes an FPGA-based architecture to accelerate the convolution operation - a complex and expensive computing step that appears in many Convolutional Neural Network models. We target the design to the standard convolution operation, intending to launch the product as an edge-AI solution. The project's purpose is to produce an FPGA IP core that can process a convolutional layer at a time. System developers can deploy the IP core with various FPGA families by using Verilog HDL as the primary design language for the architecture. The experimental results show that our single computing core synthesized on a simple edge computing FPGA board can offer 0.224 GOPS. When the board is fully utilized, 4.48 GOPS can be achieved.
description: 11 pages, 6 figures, accepted to The First International Conference on Intelligence of Things (ICIT 2022)
Modelling and simulation of power devices for high-voltage integrated circuits
Creators: name: Hünlich, Rolf
name: Albinus, Günter
name: Gajewski, Herbert
name: Glitzky, Annegret
name: Röpke, Wilfried
name: Knopke, Jürgen
Publisher: name: Weierstrass Institute
Year: 2000
Subjects: subject: Power devices
subject: integrated circuits
subject: process simulation
subject: device simulation
subject: drift-diffusion systems
subject: reaction-diffusionsystems
subject: heat flow equation
subject: thermodynamic potentials
subject: conservation laws
subject: Lyapunov functions
subject: 35B40
subject: 35B45
subject: 35K55
subject: 35K57
subject: 80A20
subject: 80A30
subject: 82D37

description: Process and device simulators turned out to be important tools in the design of high-voltage integrated circuits and in the development of their technology. The main goal of this project was the improvement of the device simulator WIAS-TeSCA in order to simulate different power devices in high-voltage integrated circuits developed by the industrial partner. Some simulation results are presented. Furthermore, we discuss some aspects of the mathematics of relevant model equations which device and process simulations are based on.
title: Das (Un-)Recht zu sterben
Creators: name: Weber, Tobias
Year: 2021

description: Die kontroversielle Debatte rund um Sterbehilfe ist keineswegs neu, sondern wurde über die Menschheitsgeschichte hinweg immer wieder geführt. Aufgrund des im Jahr 2020 getroffenen Urteils des Österreichischen Verfassungsgerichtshofs, das Verbot der Beihilfe zum Suizid aufzuheben, gewann die Debatte rund um Sterbehilfe jedoch erneut an Aktualität, Brisanz und Medienwirkung. Die vorliegende Studie machte es sich daher zum Ziel durch eine kulturpsychologische Perspektive den medialen Diskurs rund um die Sterbehilfe-Debatte in Österreich am Beispiel der Tageszeitungen „Der Standard“ und „Die Presse“ sichtbar zu machen, zeitliche Unterschiede zu etablieren und festzustellen, ob es ideologische Einflüsse entlang des politischen Spektrums oder durch die Kirche gibt. Zur Erforschung der Thematik wurde die qualitative Methodik der Kritischen Diskursanalyse nach Siegfried Jäger gewählt. Da sich der Diskurs in den beiden Tageszeitungen über einen Zeitraum von 31 Jahren und beinahe 10.000 Zeitungsartikel erstreckt, erfolgte zuerst eine Reduzierung der Materialgrundlage. Anhand von einer Reihe von Kriterien wurden 178 Diskursfragmente aus den Jahren 2014, 2015 und 2018-2020 ausgewählt und durch eine Stichprobe von 38 Diskursfragmenten aus den Jahren 1995, 1998-1999, 2001, 2005-2006, 2009-2010, 2013 und 2021 ergänzt. Diese Diskursfragmente wurden anschließend unter Anlehnung an das Instrumentarium von Jäger strukturanalytisch untersucht. In weiterer Folge wurden inhaltliche Kategorien gebildet, um die Ergebnisse bestmöglich präsentieren zu können. Die Analyse der Materialgrundlage zeigte, dass sich die Sterbehilfe-Debatte nicht auf dichotome Antworten reduzieren lässt, sondern es sich um einen außerordentlich facettenreichen Diskurs handelt. Obwohl die Debatte rund um Sterbehilfe durch den Schlagabtausch zwischen verschiedenen ideologischen Weltanschauungen geprägt ist, zeichnen sich entlang dieser extremen Sichtweisen auch eine Reihe von differenzierten Positionen ab. Der vorliegende Diskurs steht außerdem untrennbar mit dem Tabu-Thema Sterben, der Palliativ- und Hospizbetreuung, der Thematik der Übertherapie, der Patientenverfügung, dem gesellschaftlichen Umgang mit alten, kranken und schwachen Menschen sowie der Suizidprävention in Verbindung. Es handelt sich also bei der Sterbehilfe um kein isoliertes Thema, sondern vielmehr um eine Art Mosaikstein in einem Themenkomplex rund um das Lebensende. Die aktuelle Studie trägt nicht nur dazu bei, einen Überblick über den medialen Diskurs zur Sterbehilfe-Debatte in Österreich und der darin enthaltenen Nuancen zu gewinnen, die diskursive Wirkung von Aussagen hervorzuheben und Machtverhältnisse kritisch zu betrachten, sondern bietet auch einen praxisrelevanten Einblick für Psycholog*innen, Ärzt*innen und in der Pflege tätigen Berufsgruppen.
PoisFFT - A Free Parallel Fast Poisson Solver
Creators: name: Fuka, Vladimír
Publisher: name: arXiv
Year: 2014
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: G.1.2; G.1.8
subject: 65Y05, 65N06, 65N35, 76F65

description: A fast Poisson solver software package PoisFFT is presented. It is available as a free software licensed under the GNU GPL license version 3. The package uses the fast Fourier transform to directly solve the Poisson equation on a uniform orthogonal grid. It can solve the pseudo-spectral approximation and the second order finite difference approximation of the continuous solution. The paper reviews the mathematical methods for the fast Poisson solver and discusses the software implementation and parallelization. The use of PoisFFT in an incompressible flow solver is also demonstrated.
Absence of the polar Kerr effect in the helical loop-current model [Phys. Rev. Lett. 111, 047005 (2013)]
Creators: name: Pershoguba, Sergey S.
name: Kechedzhi, Kostyantyn
name: Yakovenko, Victor M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We correct our claim made in Phys. Rev. Lett. 111, 047005 (2013) that the chiral texture of loop currents can explain the experimentally observed polar Kerr effect in cuprates. Although our model does contain a bulk gyrotropic term and produces a non-zero Faraday effect on transmission, the reflection matrix of light is, nevertheless, symmetric and gives zero polar Kerr effect.
description: Erratum to Phys. Rev. Lett. 111, 047005 (2013) (http://dx.doi.org/10.1103/PhysRevLett.111.047005). Corresponds to the published version (http://dx.doi.org/10.1103/PhysRevLett.113.129901)
title: Iceland Report. Sustainable Governance Indicators 2022
Creators: name: EyÞórsson, Gretar Þór
name: Gylfason, Thorvaldur
name: Jahn, Detlef
Publisher: name: Bertelsmann Stiftung
Year: 2022
Subjects: Governance
Democracy
Regierungshandeln
Demokratie

description: In the parliamentary election in September 2021, the cabinet coalition of the Left-Green Movement, the Independence Party and the Progressive Party, which has been in office since 2017, won a renewed mandate and remained in office, reshuffling some ministries among the coalition partners.
Construction of the Unruh State for a Real Scalar Field on the Kerr-de Sitter Spacetime
Creators: name: Klein, Christiane
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The study of physical effects of quatum fields in black hole spacetimes, which is related to questions such as the validity of the strong cosmic censorship conjecture, requires a Hadamard state describing the physical situation. Here, we consider the theory of a free scalar field on a Kerr-de Sitter spacetime, focussing on spacetimes with sufficiently small angular momentum of the black hole and sufficiently small cosmological constant. We demonstrate that an extension of the Unruh state, which describes the expected late-time behaviour in spherically symmetric gravitational collapse, can be rigorously constructed for the free scalar field on such Kerr-de Sitter spacetimes. In addition, we show that this extension of the Unruh state is a Hadamard state in the black hole exterior and in the black hole interior up to the inner horizon. This provides a physically motivated Hadamard state for the study of free scalar fields in rotating black hole spacetimes.
description: 42 pages, 4 figures, 2 appendices, version as accepted for publication in Ann. Henri Poincar\'e
Gamma-ray polarization of synchrotron-self-Compton process from a highly relativistic jet
Creators: name: Chang, Zhe
name: Lin, Hai-Nan
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The high polarization observed in the prompt phase of some gamma-ray bursts (GRBs) arouses extensive studies on the emission mechanism. In this paper, we investigate the polarization properties of the synchrotron-self-Compton (SSC) process from a highly relativistic jet. A magnetic-dominated, baryon-loaded jet ejected from the central engine travels with a large Lorentz factor. Shells with slightly different velocities collide with each other and produce shocks. The shocks accelerate electrons to power-law distribution, and at the same time, magnify the magnetic field. Electrons move in the magnetic field and produce synchrotron photons. The synchrotron photons suffer from the Compton scattering (CS) process and then are detected by an observer locating slightly off-axis. We derive analytically the formulae of photon polarization in the SSC process in two magnetic configurations: magnetic field in the shock plane and perpendicular to the shock plane. We show that photons induced by the SSC process can be highly polarized, with the maximum polarization $Π\sim 24\%$ in the energy band $[0.5,5]$ MeV. The polarization depends on the viewing angles, peaking in the plane perpendicular to the magnetic field. In the energy band $[0.05,0.5]$ MeV, in which most $γ$-ray polarimeters are active, the polarization is about twice of that in the Thomson limit, reaching to $Π\sim 20\%$. This implies that the Klein-Nishina effect, which is often neglected in literatures, should be carefully considered.
description: 14 pages, 4 figures
Three-Slit Ghost Interference and Nonlocal Duality
Creators: name: Siddiqui, Mohd Asad
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A three-slit ghost interference experiment with entangled photons is theoretically analyzed using wave-packet dynamics. A non-local duality relation is derived which connects the path distinguishability of one photon to the interference visibility of the other.
description: 7 pages, 3 figures, published version
The diagonal of the multiplihedra and the tensor product of A-infinity morphisms
Creators: name: Laplante-Anfossi, Guillaume
name: Mazuir, Thibaut
Publisher: name: arXiv
Year: 2022
Subjects: subject: Algebraic Topology (math.AT)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 52B11, 18M70

description: We define a cellular approximation for the diagonal of the Forcey--Loday realizations of the multiplihedra, and endow them with a compatible topological cellular operadic bimodule structure over the Loday realizations of the associahedra. This provides us with a model for topological and algebraic A-infinity morphisms, as well as a universal and explicit formula for their tensor product. We study the monoidal properties of this newly defined tensor product and conclude by outlining several applications, notably in algebraic and symplectic topology.
description: v3 : minor corrections ; 37 pages, 11 figures ; to appear in "Journal de l'Ecole polytechnique"
title: Krisenkommunikation in Zeiten von Corona – ein Blick auf die ATX-Unternehmen
Creators: name: Trkulja, Dragana
Year: 2021

description: Die Covid-19-Pandemie hat weltweit zu enormen gesellschaftlichen Herausforderungen geführt und verheerende wirtschaftliche Folgen ausgelöst. So konnten sich auch Öster-reichs Unternehmen den volatilen Börsenkursen nicht entziehen. Die Unsicherheit war in dieser Krise besonders ausgeprägt. Vor dem Hintergrund wird in der vorliegenden Arbeit die Krisenkommunikation österreichischer Aktiengesellschaften untersucht. Das Ziel war es, die notwendigen Kommunikationsmaßnahmen herauszuarbeiten, mit denen die Unter-nehmen ihre Stakeholder durch die Krise steuern konnten. Dabei galt es auch die Auswir-kungen auf das Verhältnis zwischen Public und Investor Relations im Zuge der Krise zu ermitteln. Hierzu wurden vier leitfadengestützte Experteninterviews geführt und anhand der qualitativen Inhaltsanalyse ausgewertet. Die Ergebnisse zeigen, dass es erforderlich war, die Kommunikation zu intensivieren und auszuweiten. Die enge Kooperation zwi-schen PR und IR hat sich bewahrheitet und wurde zusätzlich bestärkt. Durch die enge Verbindung dieser beiden Bereiche wurden ebenso die Chancen und Herausforderungen einer integrierten Organisationsform untersucht. Es stellt sich heraus, dass ein einheitliches Unternehmensbild sowie konsistenter Kommunikationsfluss durch diese Konstellation ge-fördert werden kann. Herausfordernd ist es, die spezifischen Informationsbedürfnisse der Stakeholder gleichermaßen zu erfüllen, ohne von dem gemeinsamen Kommunikationsweg abzuweichen.
description: The Covid-19 pandemic has led to enormous social challenges worldwide and caused dev-astating economic consequences. Consequently, Austrian companies were also unable to escape the volatile stock market prices. Uncertainty was particularly dominant during this crisis. Against this backdrop, this study examines the crisis communication of Austrian stock corporations. The aim was to analyze the necessary communication measures with which the companies were able to guide their stakeholders through the crisis. It was also important to determine the effects on the relationship between public and investor relations in the course of the crisis. To this end, four guided interviews with experts were conducted and evaluated using the qualitative content analysis. The results show that it was necessary to intensify and expand communication. The close cooperation between PR and IR proved its worth and was further strengthened. Due to the close connection between these two areas, the opportunities and challenges of an integrated organizational form were also ex-amined. It turns out that a uniform corporate image and consistent communication flow can be supported by this constellation. The challenge is to fulfill the specific information needs of the stakeholders in equal measure without deviating from the common communication path.
Stability of zero modes in parafermion chains
Creators: name: Jermyn, Adam S.
name: Mong, Roger S. K.
name: Alicea, Jason
name: Fendley, Paul
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: One-dimensional topological phases can host localized zero-energy modes that enable high-fidelity storage and manipulation of quantum information. Majorana fermion chains support a classic example of such a phase, having zero modes that guarantee two-fold degeneracy in all eigenstates up to exponentially small finite-size corrections. Chains of `parafermions'---generalized Majorana fermions---also support localized zero modes, but, curiously, only under much more restricted circumstances. We shed light on the enigmatic zero mode stability in parafermion chains by analytically and numerically studying the spectrum and developing an intuitive physical picture in terms of domain-wall dynamics. Specifically, we show that even if the system resides in a gapped topological phase with an exponentially accurate ground-state degeneracy, higher-energy states can exhibit a splitting that scales as a power law with system size---categorically ruling out exact localized zero modes. The transition to power-law behavior is described by critical behavior appearing exclusively within excited states.
description: 15 pages, 8 figures; substantial improvements to chiral case, coauthor added. Published 7 October 2014
Non-extremal black hole solutions from the c-map
Creators: name: Errington, David
name: Mohaupt, Thomas
name: Vaughan, Owen
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct new static, spherically symmetric non-extremal black hole solutions of four-dimensional ${\cal N}=2$ supergravity, using a systematic technique based on dimensional reduction over time (the c-map) and the real formulation of special geometry. For a certain class of models we actually obtain the general solution to the full second order equations of motion, whilst for other classes of models, such as those obtainable by dimensional reduction from five dimensions, heterotic tree-level models, and type-II Calabi-Yau compactifications in the large volume limit a partial set of solutions are found. When considering specifically non-extremal black hole solutions we find that regularity conditions reduce the number of integration constants by one half. Such solutions satisfy a unique set of first order equations, which we identify. Several models are investigated in detail, including examples of non-homogeneous spaces such as the quantum deformed $STU$ model. Though we focus on static, spherically symmetric solutions of ungauged supergravity, the method is adaptable to other types of solutions and to gauged supergravity.
description: 57 pages. Minor changes to the introduction, typos corrected and references added. Accepted for publication in JHEP
The observational position of simple non-minimally coupled inflationary scenarios
Creators: name: Edwards, David C.
name: Liddle, Andrew R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider two classes of non-minimally coupled inflation models; those with a quadratic coupling of the inflaton to gravity, and the `Universal Attractor' models where the coupling is connected to the potential. We make a detailed analysis of the attractor structure in the latter case, identifying a shift of the attractor from the Starobinsky point and determining conditions for approach to the attractor. We then assess the viability of the models under different interpretations of the BICEP2 experiment's detection of B-mode polarisation, finding strong constraints on the non-minimal coupling in the case where the B-modes have mostly primordial origin.
description: 13 pages, 10 figures. Minor corrections to match JCAP accepted version
Hypernetwork-Based Adaptive Image Restoration
Creators: name: Aharon, Shai
name: Ben-Artzi, Gil
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: I.4.4

description: Adaptive image restoration models can restore images with different degradation levels at inference time without the need to retrain the model. We present an approach that is highly accurate and allows a significant reduction in the number of parameters. In contrast to existing methods, our approach can restore images using a single fixed-size model, regardless of the number of degradation levels. On popular datasets, our approach yields state-of-the-art results in terms of size and accuracy for a variety of image restoration tasks, including denoising, deJPEG, and super-resolution.
description: 5 pages, 5 Figures, ICASSP 2023
Calculation of two-centre two-electron integrals over Slater-type orbitals revisited. I. Coulomb and hybrid integrals
Creators: name: Lesiuk, Michał
name: Moszynski, Robert
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: In this paper, which constitutes the first part of the series, we consider calculation of two-centre Coulomb and hybrid integrals over Slater-type orbitals (STOs). General formulae for these integrals are derived with no restrictions on the values of the quantum numbers and nonlinear parameters. Direct integration over the coordinates of one of the electrons leaves us with the set of overlap-like integrals which are evaluated by using two distinct methods. The first one is based on the transformation to the ellipsoidal coordinates system and the second utilises a recursive scheme for consecutive increase of the angular momenta in the integrand. In both methods simple one-dimensional numerical integrations are used in order to avoid severe digital erosion connected with the straightforward use of the alternative analytical formulae. It is discussed that the numerical integration does not introduce a large computational overhead since the integrands are well-behaved functions, calculated recursively with decent speed. Special attention is paid to the numerical stability of the algorithms. Applicability of the resulting scheme over a large range of the nonlinear parameters is tested on examples of the most difficult integrals appearing in the actual calculations including at most 7i-type functions (l=6).
$D$-wave excited $cs\bar{c}\bar{s}$ tetraquark states with $J^{PC}=1^{++}$ and $1^{+-}$
Creators: name: Yang, Zi-Yan
name: Chen, Wei
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We study the mass spectra of D-wave excited $cs\bar{c}\bar{s}$ tetraquark states with $J^{PC}=1^{++}$ and $1^{+-}$ in both symmetric $\mathbf{6}_{cs}\otimes\bar{\mathbf{6}}_{\bar{c}\bar{s}}$ and antisymmetric $\bar{\mathbf{3}}_{cs}\otimes\mathbf{3}_{\bar{c}\bar{s}}$ color configurations by using the QCD sum rule method. We construct the D-wave diquark-antidiquark type of $cs\bar{c}\bar{s}$ tetraquark interpolating currents in various excitation structures with $(L_λ,L_ρ\{l_{ρ_1},l_{ρ_2}\})=(2,0\{0,0\}),(1,1\{1,0\}),(1,1\{0,1\}),(0,2\{1,1\}),(0,2\{2,0\}),(0,2\{0,2\})$. Our results support to interpret the recently observed $X(4685)$ resonance as a D-wave $cs\bar{c}\bar{s}$ tetraquark state with $J^{PC}=1^{++}$ in the $(2,0\{0,0\})$ or $(0,2\{2,0\})$ excitation mode, although some other possible excitation structures cannot be excluded exhaustively within theoretical errors. Moreover, our results provide a mass relation $6_{ρρ}<3_{λλ}<3_{λρ}<3_{ρρ}$ and $6_{ρρ}<3_{λλ}<6_{λλ}<3_{ρρ}$ for the positive and negative $\mathbb{C}$-parity D-wave $cs\bar{c}\bar{s}$ tetraquarks, respectively. We suggest searching for these possible D-wave $cs\bar{c}\bar{s}$ tetraquarks in both the hidden-charm channels $J/ψϕ$, $η_cϕ$ and open-charm channels such as $D_s\bar{D}_s^*$, $D_{s}\bar{D}_{s1}^*$ and so on.
description: 31 pages, 5 figures. Accepted by Chinese Physics C
Waveguide-integrated black phosphorus photodetector with high responsivity and low dark current
Creators: name: Youngblood, Nathan
name: Chen, Che
name: Koester, Steven J.
name: Li, Mo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Layered two-dimensional materials have shown novel optoelectronic properties and are well suited to be integrated in planar photonic circuits. For example, graphene has been utilized for wideband photodetection. Because graphene lacks a band gap, however, graphene photodetectors suffer from very high dark current. In contrast, layered black phosphorous, the latest addition to the family of 2D materials, is well-suited for photodetector applications due to its narrow but finite band gap. Here, we demonstrate a gated multilayer black phosphorus photodetector integrated on a silicon photonic waveguide operating in the near-infrared telecom band. In a significant advantage over graphene devices, black phosphorus photodetectors can operate under a bias with very low dark current and attain intrinsic responsivity up to 135 mA/W and 657 mA/W in 11.5nm and 100 nm thick devices, respectively, at room temperature. The photocurrent is dominated by the photovoltaic effect with a high response bandwidth exceeding 3 GHz.
description: 15 pages, 4 figures
Real3D-Aug: Point Cloud Augmentation by Placing Real Objects with Occlusion Handling for 3D Detection and Segmentation
Creators: name: Šebek, Petr
name: Pokorný, Šimon
name: Vacek, Patrik
name: Svoboda, Tomáš
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Object detection and semantic segmentation with the 3D lidar point cloud data require expensive annotation. We propose a data augmentation method that takes advantage of already annotated data multiple times. We propose an augmentation framework that reuses real data, automatically finds suitable placements in the scene to be augmented, and handles occlusions explicitly. Due to the usage of the real data, the scan points of newly inserted objects in augmentation sustain the physical characteristics of the lidar, such as intensity and raydrop. The pipeline proves competitive in training top-performing models for 3D object detection and semantic segmentation. The new augmentation provides a significant performance gain in rare and essential classes, notably 6.65% average precision gain for "Hard" pedestrian class in KITTI object detection or 2.14 mean IoU gain in the SemanticKITTI segmentation challenge over the state of the art.
description: Submitted on 15th June 2022 to IEEE RA-L journal
Local Group dSph radio survey with ATCA (III): Constraints on Particle Dark Matter
Creators: name: Regis, M.
name: Colafrancesco, S.
name: Profumo, S.
name: de Blok, W. J. G.
name: Massardi, M.
name: Richter, L.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.
description: 17 pages, 6 figure panels. Companion papers: arXiv:1407.5479 and arXiv:1407.5482. v3: minor revision, matches published version
title: Sorge am Krankenbett
Creators: name: Malik, Julia
Year: 2021

description: Diese Arbeit beschäftigt sich mit Praktiken und Normen der Sorge im Kontext eines öffentlichen Krankenhauses in den Philippinen. Anhand der Betrachtung von Sorgepraktiken von KrankenpflegerInnen sowie von Angehörigen der PatientInnen, von Sorgebeziehungen und von Diskursen zu Sorge beleuchte ich, wie vor Ort ,gute‘ Sorge produziert und ausgehandelt wird und wie sich AkteurInnen als ,gute‘ Sorgende positionieren. In Zusammenhang mit allgemeineren Normen zu verwandtschaftlichen Sorgeverpflichtungen spielt Sorge von Verwandten eine zentrale Rolle in den Sorgekonfigurationen rund um PatientInnen. Aushandlungen von Verantwortlichkeiten zwischen Pflegepersonal und Verwandten illustrieren, wie und wo Grenzen zwischen ,medizinisch-öffentlich‘ und ,verwandtschaftlich- privat‘ gezogen werden. PatientInnen ohne sorgende Verwandte im Krankenhaus sowie als ,anstrengend‘ empfundene Angehörige legen die mit verwandtschaftlicher Sorge einhergehenden Ambivalenzen offen. Bei den Beziehungen zwischen KrankenpflegerInnen und PatientInnen bzw. Angehörigen handelt es sich um edukative und hierarchische Sorgebeziehungen, im Rahmen derer Letztere zu Eigenverantwortlichkeit, ,besserer‘ Verwandtschaft und ,besseren‘ Sorgenden ,erzogen‘ werden sollen. Neben der Erfüllung dieses edukativen Auftrags beinhaltet die Sorge von PflegerInnen auch bürokratische Schreibpraktiken. Verwandtschaftliche Sorge, edukative Interaktionen und bürokratisches Schreiben zeichnen sich als wesentliche Elemente dessen ab, wie im Krankenhaus ,gute‘ Sorge hergestellt wird.
description: This master thesis discusses practices and norms of care in the context of a public hospital in the Philippines. I examine care practices of nurses and patients’ relatives, care relations, and discourses about care. This exploration reveals how ‘good’ care is produced and negotiated at the hospital as well as how actors position and present themselves as ‘good’ caregivers. Embedded within wider norms about kin care obligations, care by relatives plays a central role in configurations of care for patients. Negotiations of responsibilities between nursing staff and kin illustrate how boundaries between the ‘medical/public’ and ‘kinship/private’ are drawn. Patients who lack kin care at the hospital as well as kin who are perceived as ‘annoying’ by staff elucidate the ambivalences accompanying kin care. Relations between nurses and patients or relatives are educative and hierarchical care relations with the goal of ‘teaching’ patients and relatives responsibility, ‘better’ kinship, and ‘better’ care. In addition to fulfilling their pedagogical mission, care on the part of nurses also encompasses bureaucratic writing practices. Thus, kin care, educative interactions, and bureaucratic writing emerge as central elements of how ‘good’ care is produced at the hospital.
Efficient Glitch Detection in Gravitational Wave Data using Particle Swarm Optimization
Creators: name: Girgaonkar, Raghav
name: Mohanty, Soumya
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: high performance computing

description: The direct detection of Gravitational Waves (GWs) starting in 2015 has opened a new window on the observable Universe. It has uncovered previously unseen but extremely violent phenomena such as the mergers of Black Holes and Neutron Stars, also known as Compact Binary Coalescences (CBCs). However, the distance to which such CBCs can be detected is currently limited by the large false alarm rate arising from transient interference of instrumental origin, or “glitches”, in gravitational wave data. To address this problem, we propose a novel approach enabled by Particle Swarm Optimization (PSO), a nature-inspired global optimization metaheuristic. PSO offers computational efficiency surpassing traditional grid-based matched-filtering searches, allowing the search for GW signals to be expanded to unphysical sectors of the signal parameter space. While a CBC is physically characterized by the masses of the component stars (among other parameters) the preferred parameters for defining the GW signal from a CBC are the so-called chirp time parameters obtained under a non-linear transformation of the component masses. The chirp time parameter space is larger than the mass space and separates into a physical and unphysical region. We find that searching for the signals across both the regions is a very effective strategy in separating the glitch population from the astrophysical one. We observe that the glitches tend to have unphysical estimated chirp times while the astrophysical signals do not. This novel strategy can address both strong and weak glitches unlike existing strategies that are mostly effective for the former. Our method is demonstrated on 10 hours of real GW data from the LIGO detectors using a pipeline implemented on Lonestar6. On this data, we were able to identify and veto over 98% of the glitches present in GW detector data, offering a robust and efficient solution to enhance GW search sensitivity.
Using Hybrid Solvent Model to Explore the Bound Ions Effects
Creators: name: Guo, Wenhan
name: Li, Lin
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: high performance computing

description: Drosophila Ncd proteins are motor proteins that play important roles in spindle organization. It is crucial to investigate Ncd-tubulin dimer interactions in the presence of ions because the Ncd and tubulin dimer are highly charged. The widely used implicit solvent models treat ions implicitly in the continuous solvent environment, without focusing on the individual ions’ effects. But the highly charged biomolecules such as the Ncd and tubulin dimer, may capture some ions at the highly charged regions as bound ions. Such bound ions are restricted to their binding sites; thus, they can be treated as part of the biomolecules. It follows that treating the bound ions explicitly may result in more accurate calculations. By applying multi-scale computational methods, including Molecular Dynamics (MD) simulation, machine learning based Hybridizing Ions Treatment-2 (HIT-2) program, DelPhi and DelPhiForce, we studied the interaction between the Ncd motor domain and tubulin dimer using a hybrid solvent model, which considers the bound ions explicitly while the other ions implicitly in the solvent environment. We found that the calculations of the electrostatic features differ significantly between those of the hybrid solvent model and the pure implicit solvent model. The analyses show that treating bound ions at highly charged regions explicitly is crucial for electrostatic calculations. This work proposes a machine learning based approach to handle the bound ions using the hybrid solvent model. Such an approach is not only capable to handle kinesin-tubulin complexes, but also appropriate for other highly charged biomolecules.
Impact of Tricuspid Annuloplasty Device Shape and Size on Valve Mechanics: A Virtual Case Study
Creators: name: Haese, Collin E.
name: Mathur, Mrudang
name: Rausch, Manuel K.
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: high performance computing

description: "Tricuspid valve disease affects 1.6 million Americans [1]. The primary surgical treatment for tricuspid valve disease is the implantation of annuloplasty devices – ring like devices which come in various shapes and sizes. However, selection of ring size and shape are often motivated by surgeon preference rather than scientific rationale. We used our subject-specific finite element model of the human tricuspid valve, the Texas TriValve 1.0 [2], to conduct a virtual case study in order to understand the impact of device size and shape on valve mechanics and provide a rational basis for device selection. To this end, we implanted four different annuloplasty devices of six different sizes in our virtual patient. All finite element simulations were solved using the Texas Advance Computing Center’s Stampede2 supercomputer. After each virtual surgery, we computed the coaptation area, leaflet end-systolic angles, leaflet stress, and chordal forces. In Figure 1 we see the results of a baseline simulation of our healthy and diseased Texas TriValve. Figure 2 shows the outcome of all 24 virtual repair cases. Our results showed the choice of device shape and size significantly impacts valve mechanics. We found that the one flat device, the Edwards Classic, maximized coaptation area and minimized leaflet stress and chordal forces while the contoured devices were better at normalizing end-systolic angles. Further, we found reducing device size increased coaptation area while negatively impacting stress, chordal forces, and end-systolic angles. Our case study demonstrates the potential impact of device shape and size on valve mechanics. Further expanding our study to more valves may allow for universal recommendations in the future. [1] Nath, J. et al., JACC, 43:405-409, 2004. [2] Mathur, M. et. al., Eng with Comp, 38:3835-3848, 2022."
On the connection between Hopf--Galois structures and skew braces
Creators: name: Stefanello, L.
name: Trappeniers, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Number Theory (math.NT)
subject: Group Theory (math.GR)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics

description: We present a different version of the well-known connection between Hopf--Galois structures and skew braces, building on a recent paper of A. Koch and P. J. Truman. We show that the known results that involve this connection easily carry over to this new perspective, and that new ones naturally appear. As an application, we present new insights on the study of the surjectivity of the Hopf--Galois correspondence, explaining in more detail the role of bi-skew braces in Hopf--Galois theory.
description: Published in the Bulletin of the London Mathematical Society
Predicting evolution from the shape of genealogical trees
Creators: name: Neher, Richard A.
name: Russell, Colin A.
name: Shraiman, Boris I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Given a sample of genome sequences from an asexual population, can one predict its evolutionary future? Here we demonstrate that the branching patterns of reconstructed genealogical trees contains information about the relative fitness of the sampled sequences and that this information can be used to predict successful strains. Our approach is based on the assumption that evolution proceeds by accumulation of small effect mutations, does not require species specific input and can be applied to any asexual population under persistent selection pressure. We demonstrate its performance using historical data on seasonal influenza A/H3N2 virus. We predict the progenitor lineage of the upcoming influenza season with near optimal performance in 30% of cases and make informative predictions in 16 out of 19 years. Beyond providing a tool for prediction, our ability to make informative predictions implies persistent fitness variation among circulating influenza A/H3N2 viruses.