cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Ultrafast reversal of the ferroelectric polarization
Creators: name: Mankowsky, Roman
name: von Hoegen, Alexander
name: Först, Michael
name: Cavalleri, Andrea
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The ability to manipulate ferroelectrics at ultrafast speeds has long been an elusive target for materials research. Coherently exciting the ferroelectric mode with ultrashort optical pulses holds the promise to switch the ferroelectric polarization on femtosecond timescale, two orders of magnitude faster compared to what is possible today with pulsed electric fields. Here, we report on the demonstration of ultrafast optical reversal of the ferroelectric polarization in LiNbO3. Rather than driving the ferroelectric mode directly, we couple to it indirectly by resonant excitation of an auxiliary high-frequency phonon mode with femtosecond mid-infrared pulses. Due to strong anharmonic coupling between these modes, the atoms are directionally displaced along the ferroelectric mode and the polarization is transiently reversed, as revealed by time-resolved, phase-sensitive second-harmonic generation. This reversal can be induced in both directions, a key pre-requisite for practical applications.
The Evaporation and Survival of Cluster Galaxies' Coronae Part I: The Effectiveness of Isotropic Thermal Conduction Including Saturation
Creators: name: Vijayaraghavan, Rukmani
name: Sarazin, Craig
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We simulate the evolution of cluster galaxies' hot interstellar medium (ISM) gas due to ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like `wind tunnel' in our simulations. In this paper, we assume that thermal conduction is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy the evaporation time is $160$ Myr while the ram pressure stripping timescale is $2.5$ Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.
description: 18 pages, 15 figures, accepted for publication in ApJ. This preprint has been updated to the version accepted for publication
On a coupled Kadomtsev--Petviashvili system associated with an elliptic curve
Creators: name: Fu, Wei
name: Nijhoff, Frank W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The coupled Kadomtsev--Petviashvili system associated with an elliptic curve, proposed by Date, Jimbo and Miwa [J. Phys. Soc. Jpn., 52:766--771, 1983], is reinvestigated within the direct linearisation framework, which provides us with more insights into the integrability of this elliptic model from the perspective of a general linear integral equation. As a result, we successfully construct for the elliptic coupled Kadomtsev--Petviashvili system not only a Lax pair composed of differential operators in $2\times2$ matrix form but also multi-soliton solutions with phases parametrised by points on the elliptic curve. Dimensional reductions based on the direct linearisation, to the elliptic coupled Korteweg-de Vries and Boussinesq systems, are also discussed. In addition, a novel class of solutions are obtained for the $D_\infty$-type Kadomtsev--Petviashvili equation with nonzero constant background as a byproduct.
description: 27 pages
Reflexionskarte. Differenzierung der Reflexion: ein Arbeitsmittel
Creators: name: Christof Arn
name: Yolanda Martínez
Publisher: name: Zenodo
Year: 2024
Subjects: self-reflection
personal reflection
personal development
process reflection
process
agile
reflection
agile teaching
higher education
learning
future skills
competence orientation

description: Bevor man laut "Reflexion" sagt, lohnt sich die Frage: "Will ich mich überhaupt mit mir selbst auseinandersetzen?". Wo nicht, kann zwar "Reflexion" draufstehen, wird aber nicht Reflexion drin sein. Gesetzt der Fall, man will (oder auch: meine Kolleg:innen, meine Intervisionsgruppe, meine Chef:in, meine Studierenden) wollen, dann ist das hier eine interessante tabellarische Kartographierung von vier möglichen Gegenständen und vier möglichen Qualitäten der Selbstreflexion - als nicht abgeschlossene Liste. Gedacht (und ab jetzt in Erprobung) für eigene und gemeinsame Verwendung. Feedback erwünscht: christof.arn@agiledidaktik.ch .

Theoriehintergrund: Martínez Zaugg, Yolanda; Arn, Christof (2022): Reflexion, die Reflexion ist, befördert Entwicklung. In: Burk, Walter; Stalder, Christian (Hg.): Entwicklungsorientierte Bildung – ein Paradigmenwechsel. Weinheim, Beltz-Juventa. S. 196–210.
The Rosetta mission orbiter Science overview the comet phase
Creators: name: Taylor, M. G. G. T.
name: Altobelli, N.
name: Buratti, B. J.
name: Choukroun, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The International Rosetta Mission was launched in 2004 and consists of the orbiter spacecraft Rosetta and the lander Philae. The aim of the mission is to map the comet 67P Churyumov Gerasimenko by remote sensing, to examine its environment insitu and its evolution in the inner solar system.Rosetta was the first spacecraft to rendezvous and orbit a comet, accompanying it as it passes through the inner solar system, and to deploy a lander, Philae and perform in situ science on the comet surface. The primary goals of the mission were to: characterize the comets nucleus; examine the chemical, mineralogical and isotopic composition of volatiles and refractories; examine the physical properties and interrelation of volatiles and refractories in a cometary nucleus; study the development of cometary activity and the processes in the surface layer of the nucleus and in the coma; detail the origin of comets, the relationship between cometary and interstellar material and the implications for the origin of the solar system; characterize asteroids, 2867 Steins and 21 Lutetia. This paper presents a summary of mission operations and science, focusing on the Rosetta orbiter component of the mission during its comet phase, from early 2014 up to September 2016.
description: 16 pages , 3 figures, 1 table accepted for publication in Philosophical Transactions of the Royal Society A
Accelerating Earth-Bound Dark Matter
Creators: name: McKeen, David
name: Moore, Marianne
name: Morrissey, David E.
name: Pospelov, Maxim
name: Ramani, Harikrishnan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A fraction of the dark matter may consist of a particle species that interacts much more strongly with the Standard Model than a typical weakly interacting massive particle (WIMP) of similar mass. Such a strongly interacting dark matter component could have avoided detection in searches for WIMP-like dark matter through its interactions with the material in the atmosphere and the Earth that slow it down significantly before reaching detectors underground. These same interactions can also enhance the density of a strongly interacting dark matter species near the Earth's surface to well above the local galactic dark matter density. In this work we propose two new methods of detecting strongly interacting dark matter based on accelerating the enhanced population expected in the Earth through scattering. The first approach is to use underground nuclear accelerator beams to upscatter the ambient dark matter population into a WIMP-style detector located downstream. In the second technique, dark matter is upscattered with an intense thermal source and detected with a low-threshold dark matter detector. We also discuss potential candidates for strongly interacting dark matter and we show that the scenario can be naturally realized with a hidden fermion coupled to a sub-GeV dark photon.
description: 20 pages, 12 figures. v2: version accepted for publication
Detecting Majorana Zero Modes via Strong Field Dynamics
Creators: name: Baldelli, Niccolò
name: Bhattacharya, Utso
name: González-Cuadra, Daniel
name: Lewenstein, Maciej
name: Graß, Tobias
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a protocol to detect topological phase transitions of one-dimensional $p$-wave superconductors from their harmonic emission spectrum in strong fields. Specifically, we identify spectral features due to radiating edge modes, which characterize the spectrum and the density of states in the topological phase, and which are absent in the trivial phase. These features allow us to define an order parameter, obtained from emission measurements, that unambiguously differentiates between the two phases. Local probing provides insight to the localized and topologically protected nature of the modes. The presented results establish that high harmonic spectroscopy can be used as a novel all-optical tool for the detection of Majorana zero modes.
description: 6+3 pages, 5 figures
Noncommutative solutions to Zamolodchikov's tetrahedron equation and matrix six-factorisation problems
Creators: name: Konstantinou-Rizos, Sotiris
Publisher: name: arXiv
Year: 2022
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: It is known that the local Yang--Baxter equation is a generator of potential solutions to Zamolodchikov's tetrahedron equation. In this paper, we show under which additional conditions the solutions to the local Yang--Baxter equation are tetrahedron maps, namely solutions to the set-theoretical tetrahedron equation. This is exceptionally useful when one wants to prove that noncommutative maps satisfy the Zamolodchikov's tetrahedron equation. We construct new noncommutative maps and we prove that they possess the tetrahedron property. Moreover, by employing Darboux transformations with noncommutative variables, we derive noncommutative tetrahedron maps. In particular, we derive a noncommutative nonlinear Schrödinger type of tetrahedron map which can be restricted to a noncommutative version of Sergeev's map on invariant leaves. We prove that these maps are tetrahedron maps.
description: 18 pages, 2 figures. Revised version, published in Physica D
Mechanical properties of Nucleic Acids and the non-local Twistable Wormlike Chain model
Creators: name: Segers, Midas
name: Voorspoels, Aderik
name: Sakaue, Takahiro
name: Carlon, Enrico
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Mechanical properties of nucleic acids play an important role in many biological processes which often involve physical deformations of these molecules. At sufficiently long length scales (say above $\sim 20-30$ base pairs) the mechanics of DNA and RNA double helices is described by a homogeneous Twistable Wormlike Chain (TWLC), a semiflexible polymer model characterized by twist and bending stiffnesses. At shorter scales this model breaks down for two reasons: the elastic properties become sequence-dependent and the mechanical deformations at distal sites gets coupled. We discuss in this paper the origin of the latter effect using the framework of a non-local Twistable Wormlike Chain (nlTWLC). We show, by comparing all-atom simulations data for DNA and RNA double helices, that the non-local couplings are of very similar nature in these two molecules: couplings between distal sites are strong for tilt and twist degrees of freedom and weak for roll. We introduce and analyze a simple double-stranded polymer model which clarifies the origin of this universal distal couplings behavior. In this model, referred to as the ladder model, a nlTWLC description emerges from the coarsening of local (atomic) degrees of freedom into angular variables which describe the twist and bending of the molecule. Differently from its local counterpart, the nlTWLC is characterized by a length-scale-dependent elasticity. Our analysis predicts that nucleic acids are mechanically softer at the scale of a few base pairs and are asymptotically stiffer at longer length scales, a behavior which matches experimental data.
description: 14 pages, 12 figures
Unexpected advantages of exploitation for target searches in complex networks
Creators: name: Bae, Youngkyoung
name: Son, Gangmin
name: Jeong, Hawoong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Exploitation universally emerges in various decision-making contexts, e.g., animals foraging, web surfing, the evolution of scientists' research topics, and our daily lives. Despite its ubiquity, exploitation, which refers to the behavior of revisiting previous experiences, has often been considered to delay the search process of finding a target. In this paper, we investigate how exploitation affects search performance by applying a non-Markovian random walk model, where a walker randomly revisits a previously visited node using long-term memory. We analytically study two broad forms of network structures, namely (i) clique-like networks and (ii) lollipop-like networks, and find that exploitation can significantly improve search performance in lollipop-like networks whereas it hinders target search in clique-like networks. Moreover, we numerically verify that exploitation can reduce the time needed to fully explore the underlying networks by using $550$ diverse real-world networks. Based on the analytic result, we define the lollipop-likeness of a network and observe a positive relationship between the advantage of exploitation and lollipop-likeness.
description: 12 pages, 7 figures
Molecular outflows in local ULIRGs: energetics from multi-transition OH analysis
Creators: name: González-Alfonso, E.
name: Fischer, J.
name: Spoon, H. W. W.
name: Stewart, K. P.
name: Ashby, M. L. N.
name: Veilleux, S.
name: Smith, H. A.
name: Sturm, E.
name: Farrah, D.
name: Falstad, N.
name: Meléndez, M.
name: Graciá-Carpio, J.
name: Janssen, A. W.
name: Lebouteiller, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report on the energetics of molecular outflows in 14 local Ultraluminous Infrared Galaxies (ULIRGs) that show unambiguous outflow signatures (P-Cygni profiles or high-velocity absorption wings) in the far-infrared lines of OH measured with the Herschel/PACS spectrometer. Detection of both ground-state (at 119 and 79 um) and one or more radiatively-excited (at 65 and 84 um) lines allows us to model the nuclear gas (
Topological defects in a double-mirror quadrupole insulator displace diverging charge
Creators: name: Day, Isidora Araya
name: Akhmerov, Anton R.
name: Varjas, Daniel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that topological defects in quadrupole insulators do not host quantized fractional charges, contrary to what their Wannier representation indicates. In particular, we test the charge quantization hypothesis based on the Wannier representation of a parametric defect and a disclination. Against the expectations, we find that the local charge density decays as $\sim 1/r^2$ with distance, leading to a diverging defect charge. We identify sublattice symmetry and not higher order topology as the origin of the previously reported charge quantization.
description: 7 pages, 3 figures
Additional file 1 of Oakland score to identify low-risk patients with lower gastrointestinal bleeding performs well among emergency department patients
Creators: name: DiLena, Daniel D.
name: Bouvet, Sean C.
name: Somers, Madeline J.
name: Merchant, Maqdooda A.
name: Levin, Theodore R.
name: Rauchwerger, Adina S.
name: Sax, Dana R.
Publisher: name: figshare
Year: 2025
Subjects: subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Mental Health
subject: Hematology
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Supplementary Material 1
Microplankton life histories revealed by holographic microscopy and deep learning
Creators: name: Bachimanchi, Harshith
name: Midtvedt, Benjamin
name: Midtvedt, Daniel
name: Selander, Erik
name: Volpe, Giovanni
Publisher: name: arXiv
Year: 2022
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Machine Learning (cs.LG)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: The marine microbial food web plays a central role in the global carbon cycle. Our mechanistic understanding of the ocean, however, is biased towards its larger constituents, while rates and biomass fluxes in the microbial food web are mainly inferred from indirect measurements and ensemble averages. Yet, resolution at the level of the individual microplankton is required to advance our understanding of the oceanic food web. Here, we demonstrate that, by combining holographic microscopy with deep learning, we can follow microplanktons throughout their lifespan, continuously measuring their three dimensional position and dry mass. The deep learning algorithms circumvent the computationally intensive processing of holographic data and allow rapid measurements over extended time periods. This permits us to reliably estimate growth rates, both in terms of dry mass increase and cell divisions, as well as to measure trophic interactions between species such as predation events. The individual resolution provides information about selectivity, individual feeding rates and handling times for individual microplanktons. This method is particularly useful to explore the flux of carbon through micro-zooplankton, the most important and least known group of primary consumers in the global oceans. We exemplify this by detailed descriptions of micro-zooplankton feeding events, cell divisions, and long term monitoring of single cells from division to division.
description: 20 pages, 4 figure, 5 supplementary figure
The Co-Evolution of a Magnetized Intracluster Medium and Hot Galactic Coronae: Magnetic Field Amplification and Turbulence Generation
Creators: name: Vijayaraghavan, Rukmani
name: Ricker, Paul M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use adaptive-mesh magnetohydrodynamic simulations to study the effect of magnetic fields on ram pressure stripping of galaxies in the intracluster medium (ICM). Although the magnetic pressure in typical clusters is not strong enough to affect the gas mass loss rate from galaxies, magnetic fields can affect the morphology of stripped galaxies. ICM magnetic fields are draped around orbiting galaxies and aligned with their stripped tails. Magnetic fields suppress shear instabilities at the galaxy-ICM interface, and magnetized tails are smoother and narrower than tails in comparable hydrodynamic simulations in Vijayaraghavan & Ricker (2015). Orbiting galaxies stretch and amplify ICM magnetic fields, amplifying magnetic power spectra on $10 - 100$ kpc scales. Galaxies inject turbulent kinetic energy into the ICM via their turbulent wakes and $g$-waves. The magnetic energy and kinetic energy in the ICM increase up to $1.5 - 2$ Gyr of evolution, after which galaxies are stripped of most of their gas, and do not have sufficiently large gaseous cross sections to further amplify magnetic fields and inject turbulent kinetic energy. The increase in turbulent pressure due to galaxy stripping and generation of $g$-waves results in an increase in the turbulent volume fraction of the ICM. This turbulent kinetic energy is not a significant contributor to the overall ICM energy budget, but greatly impacts the evolution of the ICM magnetic field. Additionally, the effect of galaxies on magnetic fields can potentially be observed in high resolution Faraday rotation measure (RM) maps as small scale fluctuations in the RM structure.
description: 26 pages, 23 figures, accepted for publication in ApJ. This paper has been updated to reflect the version accepted for publication
OG-SGG: Ontology-Guided Scene Graph Generation. A Case Study in Transfer Learning for Telepresence Robotics
Creators: name: Amodeo, Fernando
name: Caballero, Fernando
name: Díaz-Rodríguez, Natalia
name: Merino, Luis
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Scene graph generation from images is a task of great interest to applications such as robotics, because graphs are the main way to represent knowledge about the world and regulate human-robot interactions in tasks such as Visual Question Answering (VQA). Unfortunately, its corresponding area of machine learning is still relatively in its infancy, and the solutions currently offered do not specialize well in concrete usage scenarios. Specifically, they do not take existing "expert" knowledge about the domain world into account; and that might indeed be necessary in order to provide the level of reliability demanded by the use case scenarios. In this paper, we propose an initial approximation to a framework called Ontology-Guided Scene Graph Generation (OG-SGG), that can improve the performance of an existing machine learning based scene graph generator using prior knowledge supplied in the form of an ontology (specifically, using the axioms defined within); and we present results evaluated on a specific scenario founded in telepresence robotics. These results show quantitative and qualitative improvements in the generated scene graphs.
description: 20 pages; version accepted and published in IEEE Access
Reflexionskarte. Differenzierung der Reflexion: ein Arbeitsmittel
Creators: name: Arn, Christof
name: Martínez, Yolanda
Publisher: name: Zenodo
Year: 2021
Subjects: self-reflection
personal reflection
personal development
process reflection
process
agile
reflection
agile teaching
higher education
learning
future skills
competence orientation

description: Bevor man laut "Reflexion" sagt, lohnt sich die Frage: "Will ich mich überhaupt mit mir selbst auseinandersetzen?". Wo nicht, kann zwar "Reflexion" draufstehen, wird aber nicht Reflexion drin sein. Gesetzt der Fall, man will (oder auch: meine Kolleg:innen, meine Intervisionsgruppe, meine Chef:in, meine Studierenden) wollen, dann ist das hier eine interessante tabellarische Kartographierung von vier möglichen Gegenständen und vier möglichen Qualitäten der Selbstreflexion - als nicht abgeschlossene Liste. Gedacht (und ab jetzt in Erprobung) für eigene und gemeinsame Verwendung. Feedback erwünscht: christof.arn@agiledidaktik.ch
Small moments without long-range magnetic ordering in the zero-temperature ground state of the double-perovskite iridate Ba$_2$YIrO$_6$
Creators: name: Schnait, Hermann
name: Bauernfeind, Daniel
name: Saha-Dasgupta, Tanusri
name: Aichhorn, Markus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The spin-orbit coupled double perovskite iridate Ba$_2$YIrO$_6$ with $d^4$ occupancy of Ir is considered as a candidate material for a non-magnetic $J=0$ ground state. The issue of existence of such a state in Ba$_2$YIrO$_6$ however has opened up intense debates both in experimental and theoretical studies. In this study, we revisit the issue using \textit{ab-initio} density functional combined with dynamical mean-field theory to investigate the magnetic properties of Ba$_2$YIrO$_6$ down to zero temperature. To reach the ground state, a recently developed impurity solver based on tensor-product states working directly at zero temperature is employed. We find that Ba$_2$YIrO$_6$ has a small instantaneous non-zero magnetic moment, both at $T=0$ K as well as at room temperature. We did not observe any evidence of magnetic ordering, not even at $T=0$ K. From the calculated local magnetic susceptibility we see that the quantum fluctuations are very strong and effective in screening the instantaneous moments. This dynamical screening, together with frustration effects in the fcc lattice that can lead to almost degenerate magnetic ground states, prevents any long-range ordering.
description: 11 pages, 8 figures
Solutions of Yang-Mills theory in four-dimensional de Sitter space
Creators: name: Kumar, Kaushlendra
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This doctoral work deals with the analysis of some Yang-Mills solutions on 4-dimensional de Sitter space d$S_4$. The conformal equivalence of this space with a finite Lorentzian cylinder over the 3-sphere and also with parts of Minkowski space has recently led to the discovery of a family of rational knotted electromagnetic field configurations. These "basis-knot" solutions of the Maxwell equations, aka $U(1)$ Yang-Mills theory, are labelled with the hyperspherical harmonics of the 3-sphere and have nice properties such as finite-energy, finite-action and presence of a conserved topological quantity called helicity. We study their symmetry properties, compute their conserved Noether charges for the conformal group and study behaviour of charged particles in their presence. Moreover, in the non-Abelian case of the gauge group $SU(2)$ there exist time-dependent solutions of Yang-Mills equation on d$S_4$ in terms of Jacobi elliptic functions that are of cosmological significance. These could play a role in early-time cosmology where an $SO(4)$-symmetric Higgs vacuum is stabilized due to rapid fluctuations of these gauge fields. We analyze the linear stability of such $SU(2)$ "cosmic gauge fields" against arbitrary perturbations of the Yang-Mills equation, while keeping the FLRW metric frozen. The stablity analysis of the time-dependent normal modes that arise from the diagonalization of the Yang-Mills fluctuation operator is carried out using Floquet theory.
description: PhD thesis; v2: Appendix D (codes) removed and linked in Resources, minor corrections, CV added at the end
Global Correlation and Local Information Flows in Controllable Non-Markovian Open Quantum Dynamics
Creators: name: Chen, Xin-Yu
name: Zhang, Na-Na
name: He, Wan-Ting
name: Kong, Xiang-Yu
name: Tao, Ming-Jie
name: Deng, Fu-Guo
name: Ai, Qing
name: Long, Gui-Lu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In a fully-controllable experiment platform for studying non-Markovian open quantum dynamics, we show that the non-Markovianity could be investigated from the global and local aspects. By mixing random unitary dynamics, we demonstrate non-Markovian and Markovian open quantum dynamics. From the global point of view, by tuning the base frequency we demonstrate the transition from the Markovianity to the non-Markovianity as measured by the quantum mutual information (QMI). In a Markovian open quantum process, the QMI decays monotonically, while it may rise temporarily in a non-Markovian process. However, under some circumstances, it is not sufficient to globally investigate the non-Markovianity of the open quantum dynamics. As an essential supplement, we further utilize the quantum Fisher information (QFI) flow to locally characterize the non-Markovianity in different channels. We demonstrate that the QMI in combination with the QFI flow are capable of measuring the non-Markovianity for a multi-channel open quantum dynamics.
description: 15 pages, 4 figures, to be published in npj Quantum Inf
Interspecies thermalization in an ultracold mixture of Cs and Yb in an optical trap
Creators: name: Guttridge, A.
name: Hopkins, S. A.
name: Kemp, S. L.
name: Frye, Matthew D.
name: Hutson, Jeremy M.
name: Cornish, Simon L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We present measurements of interspecies thermalization between ultracold samples of $^{133}$Cs and either $^{174}$Yb or $^{170}$Yb. The two species are trapped in a far-off-resonance optical dipole trap and $^{133}$Cs is sympathetically cooled by Yb. We extract effective interspecies thermalization cross sections by fitting the thermalization measurements to a rate equation model, giving $σ_{\mathrm{Cs^{174}Yb}} = \left(5 \pm 2\right) \times 10^{-13} \, \mathrm{cm^{2}}$ and $σ_{\mathrm{Cs^{170}Yb}} = \left(18 \pm 8\right) \times 10^{-13} \, \mathrm{cm^{2}}$. We perform quantum scattering calculations of the thermalization cross sections and optimize the CsYb interaction potential to reproduce the measurements. We predict scattering lengths for all isotopic combinations of Cs and Yb. We also demonstrate the independent production of $^{174}$Yb and $^{133}$Cs Bose-Einstein condensates using the same optical dipole trap, an important step towards the realization of a quantum-degenerate mixture of the two species.
description: 12 pages, 7 figures
Study of $B_c^+\to J/ψD_s^+$ and $B_c^+\to J/ψD_s^{*+}$ decays in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A study of $B_c^+\to J/ψD_s^+$ and $B_c^+\to J/ψD_s^{*+}$ decays using 139 fb$^{-1}$ of integrated luminosity collected with the ATLAS detector from $\sqrt{s} = 13$ TeV $pp$ collisions at the LHC is presented. The ratios of the branching fractions of the two decays to the branching fraction of the $B_c^+\to J/ψπ^+$ decay are measured: $\mathcal B(B_c^+\to J/ψD_s^+)/\mathcal B(B_c^+\to J/ψπ^+) = 2.76\pm 0.47$ and $\mathcal B(B_c^+\to J/ψD_s^{*+})/\mathcal B(B_c^+\to J/ψπ^+) = 5.33\pm 0.96$. The ratio of the branching fractions of the two decays is found to be $\mathcal B(B_c^+\to J/ψD_s^{*+})/\mathcal B(B_c^+\to J/ψD_s^+) = 1.93\pm0.26$. For the $B_c^+\to J/ψD_s^{*+}$ decay, the transverse polarization fraction, $Γ_{\pm\pm}/Γ$, is measured to be $0.70\pm0.11$. The reported uncertainties include both the statistical and systematic components added in quadrature. The precision of the measurements exceeds that in all previous studies of these decays. These results supersede those obtained in the earlier ATLAS study of the same decays with $\sqrt{s} = 7$ and 8 TeV $pp$ collision data. A comparison with available theoretical predictions for the measured quantities is presented.
description: 39 pages in total, author list starting page 23, 4 figures, 5 tables, published in JHEP. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2018-08
Reflexionskarte. Differenzierung der Reflexion: ein Arbeitsmittel
Creators: name: Arn, Christof
name: Martínez, Yolanda
Publisher: name: Zenodo
Year: 2021
Subjects: self-reflection
personal reflection
personal development
process reflection
process
agile
reflection
agile teaching
higher education
learning
future skills
competence orientation

description: "Will ich mich mit mir selbst auseinandersetzen?". Wenn ja, wird, wenn ich "Reflexion" sage, nicht nur "Reflexion" draufstehen, sondern auch Reflexion drin sein. Für diesen Fall ist die "Reflexionskarte" eine interessante tabellarische Kartographierung von vier möglichen Gegenständen und vier möglichen Qualitäten der Selbstreflexion - als nicht abgeschlossene Liste gedacht für eigene und gemeinsame Verwendung. Feedback erwünscht: christof.arn@agiledidaktik.ch
 Der theoretische Hintergrund dazu und weitere Quellenangaben sind zu finden in:
 Martínez Zaugg, Yolanda; Arn, Christof (2022): Reflexion, die Reflexion ist, befördert Entwicklung. In: Burk, Walter; Stalder, Christian (Hg.): Entwicklungsorientierte Bildung – ein Paradigmenwechsel. Weinheim, Beltz-Juventa. S. 196–210
Effect of unbalanced and common losses in quantum photonic integrated circuits
Creators: name: Li, Ming
name: Zou, Chang-Ling
name: Guo, Guang-Can
name: Ren, Xi-Feng
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Loss is inevitable for the optical system due to absorption of materials, scattering caused by the defects and surface roughness. In quantum optical circuits, the loss can not only reduce the intensity of signal, but also affect the performance of quantum operations. In this work, we divide losses into unbalanced linear loss and shared common loss, and provide a detailed analysis on how loss affects the integrated linear optical quantum gates. It is found that the orthogonality of eigenmodes and the unitary phase relation of the coupled waveguide modes are destroyed by the loss. As a result, the fidelity of single- and two-qubit operations decrease significant as the shared loss becomes comparable to the coupling strength. Our results are important for the investigation of large-scale photonic integrated quantum information process.
description: 6 pages, 4 figures
Reflexionskarte. Differenzierung der Reflexion: ein Arbeitsmittel
Creators: name: Christof Arn
name: Yolanda Martínez
Publisher: name: Zenodo
Year: 2021
Subjects: self-reflection
personal reflection
personal development
process reflection
process
agile
reflection
agile teaching
higher education
learning
future skills
competence orientation

description: Bevor man laut "Reflexion" sagt, lohnt sich die Frage: "Will ich mich überhaupt mit mir selbst auseinandersetzen?". Wo nicht, kann zwar "Reflexion" draufstehen, wird aber nicht Reflexion drin sein. Gesetzt der Fall, man will (oder auch: meine Kolleg:innen, meine Intervisionsgruppe, meine Chef:in, meine Studierenden) wollen, dann ist das hier eine interessante tabellarische Kartographierung von vier möglichen Gegenständen und vier möglichen Qualitäten der Selbstreflexion - als nicht abgeschlossene Liste. Gedacht (und ab jetzt in Erprobung) für eigene und gemeinsame Verwendung. Feedback erwünscht: christof.arn@agiledidaktik.ch
The role of low energy resonances in the stereodynamics of cold He+D2 collisions
Creators: name: Jambrina, Pablo G.
name: Morita, Masato
name: Croft, James F. E.
name: Aoiz, F. Javier
name: Balakrishnan, Naduvalath
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: In recent experiments using the Stark-induced Adiabatic Raman Passage (SARP) technique, Zhou et al. measured the product's angular distribution for the collisions between He and aligned D2 molecules at cold collision energies. The signatures of the angular distributions were attributed to a l=2 resonance that governs scattering at low energies. A first principles quantum mechanical treatment of this problem is presented here using a highly accurate interaction potential for the He-H2 system. Instead, our results predict a very intense l=1 resonance at low energies, leading to angular distributions that differ from those measured in the experiment. A good agreement with the experiment is achieved only when the l=1 resonance is artificially removed, for example, by excluding the lowest energies present in the experimental velocity distribution. Our analysis revealed that neither the position nor the intensity of the l=1 resonance significantly changes when the interaction potential is modified within its predicted uncertainties. Energy-resolved measurements may help to resolve the discrepancy.
Tunable superconducting coupling of quantum dots via Andreev bound states in semiconductor-superconductor nanowires
Creators: name: Liu, Chun-Xiao
name: Wang, Guanzhong
name: Dvir, Tom
name: Wimmer, Michael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Semiconductor quantum dots have proven to be a useful platform for quantum simulation in the solid state. However, implementing a superconducting coupling between quantum dots mediated by a Cooper pair has so far suffered from limited tunability and strong suppression. This has limited applications such as Cooper pair splitting and quantum dot simulation of topological Kitaev chains. In this work, we propose how to mediate tunable effective couplings via Andreev bound states in a semiconductor-superconductor nanowire connecting two quantum dots. We show that in this way it is possible to individually control both the coupling mediated by Cooper pairs and by single electrons by changing the properties of the Andreev bound states with easily accessible experimental parameters. In addition, the problem of coupling suppression is greatly mitigated. We also propose how to experimentally extract the coupling strengths from resonant current in a three-terminal junction. Our proposal will enable future experiments that have not been possible so far.
description: 8+9 pages, 4+5 figures
Parallel mean curvature surfaces in four-dimensional homogeneous spaces
Creators: name: Manzano, José M.
name: Torralbo, Francisco
name: Van der Veken, Joeri
Publisher: name: arXiv
Year: 2017
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: Primary 53C42, Secondary 53C30

description: We survey different classification results for surfaces with parallel mean curvature immersed into some Riemannian homogeneous four-manifolds, including real and complex space forms, and product spaces. We provide a common framework for this problem, with special attention to the existence of holomorphic quadratic differentials on such surfaces. The case of spheres with parallel mean curvature is also explained in detail, as well as the state-of-the-art advances in the general problem.
description: 19 pages, 1 table. Minor mistakes have been corrected, and some references have been added in the second and third versions
How to Train a (Bad) Algorithmic Caseworker: A Quantitative Deconstruction of Risk Assessments in Child-Welfare
Creators: name: Saxena, Devansh
name: Repaci, Charlie
name: Sage, Melanie
name: Guha, Shion
Publisher: name: arXiv
Year: 2022
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Child welfare (CW) agencies use risk assessment tools as a means to achieve evidence-based, consistent, and unbiased decision-making. These risk assessments act as data collection mechanisms and have further evolved into algorithmic systems in recent years. Moreover, several of these algorithms have reinforced biased theoretical constructs and predictors because of the easy availability of structured assessment data. In this study, we critically examine the Washington Assessment of Risk Model (WARM), a prominent risk assessment tool that has been adopted by over 30 states in the United States and has been repurposed into more complex algorithms. We compared WARM against the narrative coding of casenotes written by caseworkers who used WARM. We found significant discrepancies between the casenotes and WARM data where WARM scores did not not mirror caseworkers' notes about family risk. We provide the SIGCHI community with some initial findings from the quantitative de-construction of a child-welfare algorithm.
Search for single production of the heavy vectorlike $T$ quark with $T\to th$ and $h\to γγ$ at the high-luminosity LHC
Creators: name: Liu, Yao-Bei
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The vectorlike top partners $T$ are predicted in many extensions of the Standard Model (SM). In a simplified model including a single vectorlike $T$ quark with charge $2/3$, we investigate the process $pp \to Tj$ induced by the couplings between the top partner with the first and the third generation quarks at the LHC. We find that the mixing with the first generation can enhance the production cross section. We further study the observability of the single heavy top partner through the process $pp \to T(\to th)j\to t(\to b \ell ν_{\ell})h( \to γγ) j$ at the high-luminosity~(HL)-LHC~(a 14 TeV $pp$ collider with an integrated luminosity of 3 ab$^{-1}$). For three typical heavy $T$ quark masses $m_T=600,800$ and 1000 GeV, the $3σ$ exclusion limits, as well as the $5σ$ discovery reach in the parameter plane of the two variables $g^{\ast}-R_L$, are respectively obtained at the HL-LHC.
description: 13 pages, 10 figures, Matches with the published version
Strategic Analysis of Griefing Attack in Lightning Network
Creators: name: Mazumdar, Subhra
name: Banerjee, Prabal
name: Sinha, Abhinandan
name: Ruj, Sushmita
name: Roy, Bimal
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences

description: Hashed Timelock Contract (HTLC) in Lightning Network is susceptible to a griefing attack. An attacker can block several channels and stall payments by mounting this attack. A state-of-the-art countermeasure, Hashed Timelock Contract with Griefing-Penalty (HTLC-GP) is found to work under the classical assumption of participants being either honest or malicious but fails for rational participants. To address the gap, we introduce a game-theoretic model for analyzing griefing attacks in HTLC. We use this model to analyze griefing attacks in HTLC-GP and conjecture that it is impossible to design an efficient protocol that will penalize a malicious participant with the current Bitcoin scripting system. We study the impact of the penalty on the cost of mounting the attack and observe that HTLC-GP is weakly effective in disincentivizing the attacker in certain conditions. To further increase the cost of attack, we introduce the concept of \emph{guaranteed minimum compensation}, denoted as $ζ$, and modify HTLC-GP into $\textrm{HTLC-GP}^ζ$. By experimenting on several instances of Lightning Network, we observe that the total coins locked in the network drops to $28\%$ for $\textrm{HTLC-GP}^ζ$, unlike in HTLC-GP where total coins locked does not drop below $40\%$. These results justify that $\textrm{HTLC-GP}^ζ$ is better than HTLC-GP to counter griefing attacks.
description: 17 pages, Accepted in IEEE Transactions on Network and Service Management (Special Issue Advances on Blockchain)
Tame sets in homogeneous spaces
Creators: name: Andrist, Rafael B.
name: Ugolini, Riccardo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Complex Variables (math.CV)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 32M05, 32Q56

description: We prove the existence of strongly tame sets in affine algebraic homogenenous spaces of linear algebraic Lie groups. We also show that $(\mathbb{C}^n,A)$ for a discrete tame set enjoy the relative density property, and we provide examples of Stein manifolds admitting non-equivalent tame sets.
OCR quality affects perceived usefulness of historical newspaper clippings -- a user study
Creators: name: Kettunen, Kimmo
name: Keskustalo, Heikki
name: Kumpulainen, Sanna
name: Pääkkönen, Tuula
name: Rautiainen, Juha
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: Computation and Language (cs.CL)
subject: Digital Libraries (cs.DL)
subject: FOS: Computer and information sciences

description: Effects of Optical Character Recognition (OCR) quality on historical information retrieval have so far been studied in data-oriented scenarios regarding the effectiveness of retrieval results. Such studies have either focused on the effects of artificially degraded OCR quality (see, e.g., [1-2]) or utilized test collections containing texts based on authentic low quality OCR data (see, e.g., [3]). In this paper the effects of OCR quality are studied in a user-oriented information retrieval setting. Thirty-two users evaluated subjectively query results of six topics each (out of 30 topics) based on pre-formulated queries using a simulated work task setting. To the best of our knowledge our simulated work task experiment is the first one showing empirically that users' subjective relevance assessments of retrieved documents are affected by a change in the quality of optically read text. Users of historical newspaper collections have so far commented effects of OCR'ed data quality mainly in impressionistic ways, and controlled user environments for studying effects of OCR quality on users' relevance assessments of the retrieval results have so far been missing. To remedy this The National Library of Finland (NLF) set up an experimental query environment for the contents of one Finnish historical newspaper, Uusi Suometar 1869-1918, to be able to compare users' evaluation of search results of two different OCR qualities for digitized newspaper articles. The query interface was able to present the same underlying document for the user based on two alternatives: either based on the lower OCR quality, or based on the higher OCR quality, and the choice was randomized. The users did not know about quality differences in the article texts they evaluated. The main result of the study is that improved optical character recognition quality affects perceived usefulness of historical newspaper articles significantly. The mean average evaluation score for the improved OCR results was 7.94% higher than the mean average evaluation score of the old OCR results.
description: IRCDL2022