cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Metaverse for Safer Roadways: An Immersive Digital Twin Framework for Exploring Human-Autonomy Coexistence in Urban Transportation Systems
Creators: name: Samak, Tanmay Vilas
name: Samak, Chinmay Vilas
name: Krovi, Venkat Narayan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Societal-scale deployment of autonomous vehicles requires them to coexist with human drivers, necessitating mutual understanding and coordination among these entities. However, purely real-world or simulation-based experiments cannot be employed to explore such complex interactions due to safety and reliability concerns, respectively. Consequently, this work presents an immersive digital twin framework to explore and experiment with the interaction dynamics between autonomous and non-autonomous traffic participants. Particularly, we employ a mixed-reality human-machine interface to allow human drivers and autonomous agents to observe and interact with each other for testing edge-case scenarios while ensuring safety at all times. To validate the versatility of the proposed framework's modular architecture, we first present a discussion on a set of user experience experiments encompassing 4 different levels of immersion with 4 distinct user interfaces. We then present a case study of uncontrolled intersection traversal to demonstrate the efficacy of the proposed framework in validating the interactions of a primary human-driven, autonomous, and connected autonomous vehicle with a secondary semi-autonomous vehicle. The proposed framework has been openly released to guide the future of autonomy-oriented digital twins and research on human-autonomy coexistence.
description: Accepted at IEEE Conference on Telepresence (TELE) 2024
Semi-analytic derivation of the threshold mass for prompt collapse in binary neutron star mergers
Creators: name: Bauswein, Andreas
name: Stergioulas, Nikolaos
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The threshold mass for prompt collapse in binary neutron star mergers was empirically found to depend on the stellar properties of the maximum-mass non-rotating neutron star model. Here we present a semi-analytic derivation of this empirical relation which suggests that it is rather insensitive to thermal effects, to deviations from axisymmetry and to the exact rotation law in merger remnants. We utilize axisymmetric, cold equilibrium models with differential rotation and determine the threshold mass for collapse from the comparison between an empirical relation that describes the angular momentum in the remnant for a given total binary mass and the sequence of rotating equilibrium models at the threshold to collapse (the latter assumed to be near the turning point of fixed-angular-momentum sequences). In spite of the various simplifying assumptions, the empirical relation for prompt collapse is reproduced with good accuracy, which demonstrates its robustness. We discuss implications of our methodology and results for understanding other empirical relations satisfied by neutron-star merger remnants that have been discovered by numerical simulations and that play a key role in constraining the high-density equation of state through gravitational-wave observations.
description: 11 pages, 9 figures, 1 table; accepted for publication in MNRAS
Entanglement and coherence in a spin-s XXZ system under non-uniform fields
Creators: name: Rios, E.
name: Rossignoli, R.
name: Canosa, N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate entanglement and coherence in an $XXZ$ spin-$s$ pair immersed in a non-uniform transverse magnetic field. The ground state and thermal entanglement phase diagrams are analyzed in detail in both the ferromagnetic and antiferromagnetic cases. It is shown that a non-uniform field enables to control the energy levels and the entanglement of the corresponding eigenstates, making it possible to entangle the system for any value of the exchange couplings, both at zero and finite temperatures. Moreover, the limit temperature for entanglement is shown to depend only on the difference $|h_1-h_2|$ between the fields applied at each spin, leading for $T>0$ to a separability stripe in the $(h_1,h_2)$ field plane such that the system becomes entangled above a threshold value of $|h_1-h_2|$. These results are demonstrated to be rigorously valid for any spin $s$. On the other hand, the relative entropy of coherence in the standard basis, which coincides with the ground state entanglement entropy at $T=0$ for any $s$, becomes non-zero for any value of the fields at $T>0$, decreasing uniformly for sufficiently high $T$. A special critical point arising at $T=0$ for non-uniform fields in the ferromagnetic case is also discussed
description: 18 pages, 9 figures, final version
Enhancing sideband cooling by feedback--controlled light
Creators: name: Rossi, Massimiliano
name: Kralj, Nenad
name: Zippilli, Stefano
name: Natali, Riccardo
name: Borrielli, Antonio
name: Pandraud, Gregory
name: Serra, Enrico
name: Di Giuseppe, Giovanni
name: Vitali, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We realise a phase-sensitive closed-loop control scheme to engineer the fluctuations of the pump field which drives an optomechanical system, and show that the corresponding cooling dynamics can be significantly improved. In particular, operating in the counter-intuitive "anti-squashing" regime of positive feedback and increased field fluctuations, sideband cooling of a nanomechanical membrane within an optical cavity can be improved by 7.5~dB with respect to the case without feedback. Close to the quantum regime of reduced thermal noise, such feedback-controlled light would allow going well below the quantum backaction cooling limit.
One More Hard Three-Loop Correction to Parapositronium Energy Levels
Creators: name: Eides, Michael I.
name: Shelyuto, Valery A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A hard three-loop correction to parapositronium energy levels of order $mα^7$ is calculated. This nonlogarithmic contribution is due to the insertions of one-loop photon propagator in the fermion lines in the diagrams with virtual two-photon annihilation. We obtained $ΔE=0.03297(2)(mα^7/π^3)$ for this energy shift.
description: Version to be published in Phys. Rev.D, results unchanged
Displacements and evolution of optical vortices in edge-diffracted Laguerre-Gaussian beams
Creators: name: Bekshaev, Aleksandr
name: Chernykh, Aleksey
name: Khoroshun, Anna
name: Mikhaylovskaya, Lidiya
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Based on the Kirchhoff-Fresnel approximation, we consider behavior of the optical vortices (OV) upon propagation of the diffracted Laguerre-Gaussian (LG) beams with topological charge |m| = 1, 2. Under conditions of weak diffraction perturbation (i.e. the diffraction obstacle covers only the far transverse periphery of the incident LG beam), the OVs describe almost perfect 3D spirals within the diffracted beam body, which is an impressive demonstration of the helical nature of an OV beam. The far-field OV positions within the diffracted beam cross section depend on the wavefront curvature of the incident OV beam so that the input wavefront curvature is transformed into the output azimuthal OV rotation. The results can be useful in the OV metrology and for the OV beam's diagnostics.
description: 12 pages, 7 figures
Virtual to Real Reinforcement Learning for Autonomous Driving
Creators: name: Pan, Xinlei
name: You, Yurong
name: Wang, Ziyan
name: Lu, Cewu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Reinforcement learning is considered as a promising direction for driving policy learning. However, training autonomous driving vehicle with reinforcement learning in real environment involves non-affordable trial-and-error. It is more desirable to first train in a virtual environment and then transfer to the real environment. In this paper, we propose a novel realistic translation network to make model trained in virtual environment be workable in real world. The proposed network can convert non-realistic virtual image input into a realistic one with similar scene structure. Given realistic frames as input, driving policy trained by reinforcement learning can nicely adapt to real world driving. Experiments show that our proposed virtual to real (VR) reinforcement learning (RL) works pretty well. To our knowledge, this is the first successful case of driving policy trained by reinforcement learning that can adapt to real world driving data.
Exploring Alternative Cosmologies with the LSST: Simulated Forecasts and Current Observational Constraints
Creators: name: Kumar, Dharmendra
name: Mitra, Ayan
name: Adil, Shahnawaz A.
name: Sen, Anjan A.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In recent years, the Lambda Cold Dark Matter (LCDM) model, which has been pivotal in cosmological studies, has faced significant challenges due to emerging observational and theoretical inconsistencies. This paper explores alternative cosmological models to address these discrepancies, using simulated three years photometric Supernovae Ia data from the Legacy Survey of Space and Time (LSST), supplemented with additional Pantheon+, Union, and the recently released Dark Energy Survey 5 Years (DESY5) supernova compilations and Baryon Acoustic Oscillation (BAO) measurements. We assess the constraining power of these datasets on various dynamic dark energy models, including CPL, BA, JBP, SCPL, and GCG. Our analysis demonstrates that the LSST with its high precision data, can provide tighter constraints on dark energy parameters compared to other datasets. Additionally, the inclusion of BAO measurements significantly improves parameter constraints across all models.
 Except for Pantheon+, we find that across all the cosmological datasets, and the dark energy models considered in this work, there is a consistent deviation from the LCDM model that exceeds a 2-sigma significance level. Our findings underscore the necessity of exploring dynamic dark energy models, which offer more consistent frameworks with fundamental physics and observational data, potentially resolving tensions within the LCDM paradigm. Furthermore, the use of simulated LSST data highlights the survey's potential in offering significant advantages for exploring alternative cosmologies, suggesting that future LSST observations would play a crucial role.
description: 7 figures, 13 pages. To be submitted to journal
Sub-$μ$eV Decoherence-Induced Population Pulsation Resonances in an InGaN system
Creators: name: Nelson, Cameron
name: Ra, Yong-Ho
name: Mi, Zetian
name: Berman, Paul
name: Steel, Duncan G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report on high frequency resolution coherent nonlinear optical spectroscopy on an ensemble of InGaN disks in GaN nanowires at 300 K. Sub-$μ$eV resonances in the inhomogeneously broadened third order ($χ^{(3)}$) absorption spectrum show asymmetric line shapes, where the degree of asymmetry depends on the wavelength of the excitation beams. Theory based on the Optical Bloch Equations (OBE) indicates that the lineshape asymmetry is a result of fast decoherence in the system and the narrow resonances originate from coherent population pulsations that are induced by decoherence in the system. Using the OBE, we estimate that the decoherence time of the optically induced dipole (formed between the unexcited ground state the excited electron-hole pair) at room temperature is 125 fs, corresponding to a linewidth of ~10 meV. The decay time of the excitation is ~5-10 ns, depending on the excitation energy. The lineshapes are well fit with the OBE indicating that the resonances are characterized by discrete levels with no evidence of many body physics.
description: 7 pages, 4 figures
Devil's staircases in synthetic dimensions and gauge fields
Creators: name: Saito, Takeshi Y.
name: Furukawa, Shunsuke
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study interacting bosonic or fermionic atoms in a high synthetic magnetic field in two dimensions spanned by continuous real space and a synthetic dimension. Here, the synthetic dimension is provided by hyperfine spin states, and the synthetic field is created by laser-induced transitions between them. While the interaction is short-range in real space, it is long-range in the synthetic dimension in sharp contrast with fractional quantum Hall systems. Introducing an analog of the lowest-Landau-level approximation valid for large transition amplitudes, we derive an effective one-dimensional lattice model, in which density-density interactions turn out to play a dominant role. We show that in the limit of a large number of internal states, the system exhibits a cascade of crystal ground states, which is known as devil's staircase, in a way analogous to the thin-torus limit of quantum Hall systems.
description: 9 pages, 4 figures
Spectral Fidelity and Asteroseismology
Creators: name: Miglio, Andrea
Publisher: name: Zenodo
Year: 2023
Subjects: galactic archaeology
asteroseismology
haydn

description: Seismic constraints on stellar surface gravities have been instrumental in improving spectroscopic pipelines. On the other hand, constraints on photospheric chemical abundances are a necessary ingredient to any inference about global stellar properties, and to enable robust tests of stellar internal structures. In this contribution I will review the synergies between stellar spectroscopy and asteroseismology and discuss current limitations and future prospects, in particular in the light of current and future space-photometry missions such as PLATO and the ESA candidate M7 mission HAYDN.
Surface defects and instanton-vortex interaction
Creators: name: Gorsky, A.
name: Floch, B. Le
name: Milekhin, A.
name: Sopenko, N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose a simple formula for the 4d-2d partition function of half-BPS surface defects in $d=4,\ \mathcal{N}=2$ gauge theories: $Z^{\text{4d-2d}}=\langle Z^{\text{2d}} \rangle_{\text{4d}}$. Our results are applicable for any surface defect obtained by gauging a 2d flavour symmetry using a 4d gauge group. For defects obtained via the Higgsing procedure, our formula reproduces the recent calculation by Pan and Peelaers. For Gukov-Witten defects our results reproduce the orbifold calculation by Kanno and Tachikawa. We emphasize the role of "negative vortices" which are realized as negative D0 branes.
description: v1: 40 pages, 8 figures, v2: clarifications and references added
Tailoring Generative AI Chatbots for Multiethnic Communities in Disaster Preparedness Communication: Extending the CASA Paradigm
Creators: name: Zhao, Xinyan
name: Sun, Yuan
name: Liu, Wenlin
name: Wong, Chau-Wai
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences
subject: 68U15

description: This study is among the first to develop different prototypes of generative artificial intelligence (GenAI) chatbots powered by GPT-4 to communicate hurricane preparedness information to diverse residents. Drawing from the Computers Are Social Actors paradigm and the literature on disaster vulnerability and cultural tailoring, we conducted a between-subjects experiment with 441 Black, Hispanic, and Caucasian residents of Florida. Our results suggest that GenAI chatbots varying in tone formality and cultural tailoring significantly influence perceptions of their friendliness and credibility, which, in turn, relate to hurricane preparedness outcomes. These results highlight the potential of using GenAI chatbots to improve diverse communities' disaster preparedness.
description: Accepted for Publication in Journal of Computer-Mediated Communication
Slim Fractals: The Geometry of Doubly Transient Chaos
Creators: name: Chen, Xiaowen
name: Nishikawa, Takashi
name: Motter, Adilson E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Traditional studies of chaos in conservative and driven dissipative systems have established a correspondence between sensitive dependence on initial conditions and fractal basin boundaries, but much less is known about the relation between geometry and dynamics in undriven dissipative systems. These systems can exhibit a prevalent form of complex dynamics, dubbed doubly transient chaos because not only typical trajectories but also the (otherwise invariant) chaotic saddles are transient. This property, along with a manifest lack of scale invariance, has hindered the study of the geometric properties of basin boundaries in these systems--most remarkably, the very question of whether they are fractal across all scales has yet to be answered. Here we derive a general dynamical condition that answers this question, which we use to demonstrate that the basin boundaries can indeed form a true fractal; in fact, they do so generically in a broad class of transiently chaotic undriven dissipative systems. Using physical examples, we demonstrate that the boundaries typically form a slim fractal, which we define as a set whose dimension at a given resolution decreases when the resolution is increased. To properly characterize such sets, we introduce the notion of equivalent dimension for quantifying their relation with sensitive dependence on initial conditions at all scales. We show that slim fractal boundaries can exhibit complex geometry even when they do not form a true fractal and fractal scaling is observed only above a certain length scale at each boundary point. Thus, our results reveal slim fractals as a geometrical hallmark of transient chaos in undriven dissipative systems.
description: 13 pages, 9 figures, proof corrections implemented
Measuring X-ray anisotropy in solar flares. Prospective stereoscopic capabilities of STIX and MiSolFA
Creators: name: Casadei, Diego
name: Jeffrey, Natasha L. S.
name: Kontar, Eduard P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: During the next solar maximum, two upcoming space-borne X-ray missions, STIX on board Solar Orbiter and MiSolFA, will perform stereoscopic X-ray observations of solar flares at two different locations: STIX at 0.28 AU (at perihelion) and up to inclinations of $\sim25^{\circ}$, and MiSolFA in a low-Earth orbit. The combined observations from these cross-calibrated detectors will allow us to infer the electron anisotropy of individual flares confidently for the first time. We simulated both instrumental and physical effects for STIX and MiSolFA including thermal shielding, background and X-ray Compton backscattering (albedo effect) in the solar photosphere. We predict the expected number of observable flares available for stereoscopic measurements during the next solar maximum. We also discuss the range of useful spacecraft observation angles for the challenging case of close-to-isotropic flare anisotropy. The simulated results show that STIX and MiSolFA will be capable of detecting low levels of flare anisotropy, for M1-class or stronger flares, even with a relatively small spacecraft angular separation of 20-30°. Both instruments will directly measure the flare X-ray anisotropy of about 40 M- and X-class solar flares during the next solar maximum. Near-future stereoscopic observations with Solar Orbiter/STIX and MiSolFA will help distinguishing between competing flare-acceleration mechanisms, and provide essential constraints regarding collisional and non-collisional transport processes occurring in the flaring atmosphere for individual solar flares.
Causality and Unitarity via the Tree-Loop Duality Relation
Creators: name: Tomboulis, E. T.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The tree-loop duality relation is used as a starting point to derive the constraints of causality and unitarity. Specifically, the Bogoliubov causality condition is ab initio derived at the individual graph level. It leads to a representation of a graph in terms of lower order cut graphs. Extracting the absorptive part gives then the general unitarity relation (Cutkosky rule). The derivation, being carried out directly in momentum space, holds for any local (polynomial) hermitian interaction vertices. This is in contrast to the technical difficulties arising from contact terms in the spacetime approach based on the largest time equation.
description: 23 pages, 5 figures, typos corrected, some added references and concluding remarks, published version
The effect of phase change on stability of convective flow in a layer of volatile liquid driven by a horizontal temperature gradient
Creators: name: Grigoriev, Roman O.
name: Qin, Tongran
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Buoyancy-thermocapillary convection in a layer of volatile liquid driven by a horizontal temperature gradient arises in a variety of situations. Recent studies have shown that the composition of the gas phase, which is typically a mixture of vapour and air, has a noticeable effect on the critical Marangoni number describing the onset of convection as well as on the observed convection pattern. Specifically, as the total pressure or, equivalently, the average concentration of air is decreased, the threshold of the instability leading to the emergence of convective rolls is found to increase rather significantly. We present a linear stability analysis of the problem which shows that this trend can be readily understood by considering the transport of heat and vapour through the gas phase. In particular, we show that transport in the gas phase has a noticeable effect even at atmospheric conditions, when phase change is greatly suppressed.
THE TRAINING AND DEVELOPMENT PRACTICE OF PLASTIC INDUSTRIYAND ITS EFFECT ON EMPLOYEES PERFORMANCE. (THE CASE OF GEOSYNTHETICS INDUSTRIAL WORKS PLC)
Creators: name: DeresseTsegaye
Publisher: name: Zenodo
Year: 2017

description: THE TRAINING AND DEVELOPMENT PRACTICE OF PLASTIC

INDUSTRIYAND ITS EFFECT ON EMPLOYEES PERFORMANCE. (THE

CASE OF GEOSYNTHETICS INDUSTRIAL WORKS PLC)
Handbook of standard methods for testing invertebrate Ecosystem Service Providers for resistance to pesticides
Creators: name: Bednarska, Agnieszka
name: Frydryszak, Danuta
name: Laskowski, Ryszard
name: Sarmento, Artur
name: Sousa, Paulo
Publisher: name: Zenodo
Year: 2023
Subjects: Ecosystem Service Providers
insecticides
testing
standard operating procedures
bioassays
Non-Target Arthropods

description: Deliverable 7.1 of the EcoStack project - "Methods for testing ESPs insecticide resistance"
The Structural Fate of Individual Multicomponent Metal-Oxide Nanoparticles in Polymer Nanoreactors
Creators: name: Du, Jingshan S.
name: Chen, Peng-Cheng
name: Meckes, Brian
name: Xie, Zhuang
name: Zhu, Jinghan
name: Liu, Yuan
name: Dravid, Vinayak P.
name: Mirkin, Chad A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Multicomponent nanoparticles can be synthesized with either homogeneous or phase-segregated architectures depending on the synthesis conditions and elements incorporated. To understand the parameters that determine their structural fate, multicomponent metal-oxide nanoparticles consisting of combinations of Co, Ni, and Cu were synthesized via scanning probe block copolymer lithography and characterized using correlated electron microscopy. These studies revealed that the miscibility, ratio of the metallic components, and the synthesis temperature determine the crystal structure and architecture of the nanoparticles. A Co-Ni-O system forms a rock salt structure largely due to the miscibility of CoO and NiO, while Cu-Ni-O, which has large miscibility gaps, forms either homogeneous oxides, heterojunctions, or alloys depending on the annealing temperature and composition. Moreover, a higher ordered structure, Co-Ni-Cu-O, was found to follow the behavior of lower ordered systems.
description: 7 pages, 3 figures, 1 scheme. Accepted for publication in Angewandte Chemie
title: Conservation According to the Pure Theory of Exhaustible Resources
Creators: name: Lymbouris, George
Publisher: name: Old Dominion University Libraries
Year: 1978

description: The objective of this thesis is to develop a theory for defining optimal conservation and applying definition to the prevailing rate of domestic petroleum production. Optimal conservation is defined as action designed to achieve or to maintain, from the point of view of society as a whole, the maximum present valu~ of natural resources (or of a natural resource). The proper "action" is defined according to the pure theory of exhaustible resources. The literature survey is a chronological series of articles concerning this theory.

Through building a model which shows that optimal conservation occurs when the marginal internal rate of return is equal to the market rate of interest, adjusted for risk and uncertainty, this paper is able to determine whether the prevailing rate of domestic petroleum fits this definition or not. Testing data for newly discovered United States petroleum reserves for years 1959 through 1975 we concluded that the prevailing rate of discoveries is less than optimal conservation amount.

Finally, we propose the reason for this dilemma and propose a policy of unitization to correct the discovered problem.
The Games Collection at the German Literature Archive (DLA)
Creators: name: Kozlik, Andreas
Publisher: name: Zenodo
Year: 2023
Subjects: literature archive
literature
archive
computer games
video games
library

description: Within its collecting mandate, the library of the German Literature Archive Marbach (Deutsches Literaturarchiv Marbach) also acquires, indexes, and archives computer games that contain traces of literary reception or whose narrative character could be of particular interest for literary research. At the beginning of the conference "Games & Literature. On the literaricity, research, collection, and archiving of computer games", Andreas Kozlik gave a short introduction about the computer game collection that is being built up at the German Literature Archive Marbach (DLA) and its collection criteria.
Quantum synchronization as a local signature of super- and subradiance
Creators: name: Bellomo, B.
name: Giorgi, G. L.
name: Palma, G. M.
name: Zambrini, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the relationship between the collective phenomena of super and subradiance and spontaneous synchronization of quantum systems. To this aim we revisit the case of two detuned qubits interacting through a pure dissipative bosonic environment, which contains the minimal ingredients for our analysis. By using the Liouville formalism, we are able to find analytically the ultimate connection between these phenomena. We find that dynamical synchronization is due to the presence of long standing coherence between the ground state of the system and the subradiant state. We finally show that, under pure dissipation, the emergence of spontaneous synchronization and of subradiant emission occur on the same time scale. This reciprocity is broken in the presence of dephasing noise.
description: 12 pages, 6 figures
Symmetry reduction induced by anyon condensation: a tensor network approach
Creators: name: Garre-Rubio, José
name: Iblisdir, Sofyan
name: Pérez-García, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Topological ordered phases are related to changes in the properties of their quasi-particle excitations (anyons). We study these relations in the framework of projected entanglement pair states (\textsf{PEPS}) and show how condensing and confining anyons reduces a local gauge symmetry to a global on-site symmetry. We also study the action of this global symmetry over the quasiparticle excitations. As a byproduct, we observe that this symmetry reduction effect can be applied to one-dimensional systems as well, and brings about appealing physical interpretations on the classification of phases with symmetries using matrix product states (\textsf{MPS}). The case of $\mathbb{Z}_2$ on-site symmetry is studied in detail.
description: 21+5 pages, 15+3 figures. Introduction and conclusions enlarged, references and figure added, minor typos corrected, appendix about dyons added
BaSeNet: A Learning-based Mobile Manipulator Base Pose Sequence Planning for Pickup Tasks
Creators: name: Naik, Lakshadeep
name: Kalkan, Sinan
name: Sørensen, Sune L.
name: Kjærgaard, Mikkel B.
name: Krüger, Norbert
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: In many applications, a mobile manipulator robot is required to grasp a set of objects distributed in space. This may not be feasible from a single base pose and the robot must plan the sequence of base poses for grasping all objects, minimizing the total navigation and grasping time. This is a Combinatorial Optimization problem that can be solved using exact methods, which provide optimal solutions but are computationally expensive, or approximate methods, which offer computationally efficient but sub-optimal solutions. Recent studies have shown that learning-based methods can solve Combinatorial Optimization problems, providing near-optimal and computationally efficient solutions.
 In this work, we present BASENET - a learning-based approach to plan the sequence of base poses for the robot to grasp all the objects in the scene. We propose a Reinforcement Learning based solution that learns the base poses for grasping individual objects and the sequence in which the objects should be grasped to minimize the total navigation and grasping costs using Layered Learning. As the problem has a varying number of states and actions, we represent states and actions as a graph and use Graph Neural Networks for learning. We show that the proposed method can produce comparable solutions to exact and approximate methods with significantly less computation time.
description: Submitted to IROS 2024
Motion of skyrmions in nanowires driven by magnonic momentum-transfer forces
Creators: name: Zhang, Xichao
name: Müller, Jan
name: Xia, Jing
name: Garst, Markus
name: Liu, Xiaoxi
name: Zhou, Yan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the motion of magnetic skyrmions in a nanowire induced by a spin-wave current $J$ flowing out of a driving layer close to the edge of the wire. By applying micromagnetic simulation and an analysis of the effective Thiele equation, we find that the skyrmion trajectory is governed by an interplay of both forces due to the magnon current and the wire boundary. The skyrmion is attracted to the driving layer and is accelerated by the repulsive force due to the wire boundary. We consider both cases of a driving longitudinal and transverse to the nanowire, but a steady-state motion of the skyrmion is only obtained for a transverse magnon current. For the latter case, we find in the limit of low current densities $J$ the velocity-current relation $v \sim J/α$ where $v$ is the skyrmion velocity and $α$ is the Gilbert damping. For large $J$ in case of strong driving, the skyrmion is pushed into the driving layer resulting in a drop of the skyrmion velocity and, eventually, the destruction of the skyrmion.
description: 9 pages, 7 figures. Published in NJP Special Issue: Focus on Magnetic Skyrmions
Note on asymptotic symmetries and soft gluon theorems
Creators: name: Mao, Pujian
name: Wu, Jun-Bao
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently, the leading soft gluon theorem with single soft emission was shown to be the Ward identity of a two dimensional $\cal G$-Kac-Moody symmetry. In this note, we show that the leading soft gluon theorem can be interpreted as the Ward identity for the asymptotic symmetries of non-Abelian gauge theory. We further argue that the sub-leading soft gluon theorem can follow from the same symmetry.
description: v3: minor corrections, published version
Simplified Phenomenology for Colored Dark Sectors
Creators: name: Hedri, Sonia El
name: Kaminska, Anna
name: de Vries, Maikel
name: Zurita, Jose
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We perform a general study of the relic density and LHC constraints on simplified models where the dark matter coannihilates with a strongly interacting particle X. In these models, the dark matter depletion is driven by the self-annihilation of X to pairs of quarks and gluons through the strong interaction. The phenomenology of these scenarios therefore only depends on the dark matter mass and the mass splitting between dark matter and X as well as the quantum numbers of X. In this paper, we consider simplified models where X can be either a scalar, a fermion or a vector, as well as a color triplet, sextet or octet. We compute the dark matter relic density constraints taking into account Sommerfeld corrections and bound state formation. Furthermore, we examine the restrictions from thermal equilibrium, the lifetime of X and the current and future LHC bounds on X pair production. All constraints are comprehensively presented in the mass splitting versus dark matter mass plane. While the relic density constraints can lead to upper bounds on the dark matter mass ranging from 2 TeV to more than 10 TeV across our models, the prospective LHC bounds range from 800 to 1500 GeV. A full coverage of the strongly coannihilating dark matter parameter space would therefore require hadron colliders with significantly higher center of mass energies.
description: 34 pages, 8 figures, matches JHEP version
Conductance of a superconducting Coulomb blockaded Majorana nanowire
Creators: name: Chiu, Ching-Kai
name: Sau, Jay D.
name: Sarma, S. Das
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In the presence of an applied magnetic field introducing Zeeman spin splitting, a superconducting (SC) proximitized one-dimensional (1D) nanowire with spin-orbit coupling can pass through a topological quantum phase transition developing zero-energy topological Majorana bound states (MBSs) on the wire ends. One of the promising experimental platforms in this context is a Coulomb blockaded island, where by measuring the two-terminal conductance one can in principle investigate the MBS properties. We theoretically study the tunneling transport of a single electron across the superconducting Coulomb blockaded nanowire at finite temperature to obtain the generic conductance equation. By considering all possible scenarios where only MBSs are present at the ends of the nanowire, we compute the nanowire conductance as a function of the magnetic field, the temperature, and the gate voltage. In the simplest 1D topological SC model, the oscillations of the conductance peak spacings (OCPSs) arising from the MBSs overlap from the two wire ends manifest an increasing oscillation amplitude with increasing magnetic field (in agreement with theories without Coulomb blockade and in disagreement with a recent experimental observation). We develop a generalized finite temperature master equation theory including not only multiple subbands in the nanowire, but also the possibility of ordinary Andreev bound states in the non-topological regime. Inclusion of all four effects (temperature, multiple subbands, Andreev bound states, and MBSs) provides a complete picture of the tunneling transport properties. Based on this complete theory, we indeed obtain OCPSs whose amplitudes decrease with increasing magnetic field in qualitative agreement with recent experimental results, but this happens only for rather high temperatures with multisubband occupancy and the presence of both Andreev bound states and MBSs.
description: 23 pages, 12 figures
A Rao-Blackwellized Particle Filter for Superelliptical Extended Target Tracking
Creators: name: Yurdakul, Oğul Can
name: Çetinkaya, Mehmet
name: Çelebi, Enescan
name: Özkan, Emre
Publisher: name: arXiv
Year: 2024
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this work, we propose a new method to track extended targets of different shapes such as ellipses, rectangles and rhombi. We provide an analytical framework to express these shapes as superelliptical contours and propose a Bayesian filtering scheme that can handle measurements from the contour of the object. The method utilizes the Rao-Blackwellized particle filtering algorithm with novel sensor-object geometry constraints. The success of the algorithm is demonstrated using both simulations and real-data experiments, and the algorithm has been demonstrated to be of high performance in various challenging scenarios.
description: 10 pages, 6 figures, accepted by the 27th International Conference on Information Fusion (FUSION 2024). This version introduces equation (23) with the necessary modifications. The scaling factor is chosen to yield the same results
Escape of harmonically forced classical particle from an infinite-range potential well
Creators: name: Gendelman, O. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Physics (physics.class-ph)
subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The paper considers a process of escape of classical particle from a one-dimensional potential well by virtue of an external harmonic forcing. We address a particular model of the infinite-range potential well that allows independent adjustment of the well depth and of the frequency of small oscillations. The problem can be conveniently reformulated in terms of action-angle variables. Further averaging provides a nontrivial conservation law for the slow flow. Thus, one can consider the problem in terms of averaged dynamics on primary 1:1 resonance manifold. This simplification allows efficient analytic exploration of the escape process, and yields a theoretical prediction for minimal forcing amplitude required for the escape, as a function of the excitation frequency. This function exhibits a single minimum for certain intermediate frequency value. Numeric simulations are in complete qualitative and reasonable quantitative agreement with the theoretical predictions.
Optimized spin-injection efficiency and spin MOSFET operation based on low-barrier ferromagnet/insulator/n-Si tunnel contact
Creators: name: Yang, Yang
name: Wu, Zhenhua
name: Yang, Wen
name: Li, Jun
name: Chen, Songyan
name: Li, Cheng
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically investigate the spin injection in different FM/I/n-Si tunnel contacts by using the lattice NEGF method. We find that the tunnel contacts with low barrier materials such as TiO$_2$ and Ta$_{2}$O$_{5}$, have much lower resistances than the conventional barrier materials, resulting in a wider and attainable optimum parameters window for improving the spin injection efficiency and MR ratio of a vertical spin MOSFET. Additionally, we find the spin asymmetry coefficient of TiO$_2$ tunnel contact has a negative value, while that of Ta$_{2}$O$_{5}$ contact can be tuned between positive and negative values, by changing the parameters.
Ribosomenbiogenese in Archaeen
Creators: name: Jüttner, Michael
name: Ferreira-Cerca, Sébastien
Publisher: name: Universität Regensburg
Year: 2022
Subjects: subject: 570 Biowissenschaften, Biologie

description: The ribosome is a universally conserved macromolecular machine responsible for the translation of mRNAs into proteins. The synthesis of ribosomes is a crucial task that has been well characterized in bacteria and eukarya, but not in archaea. Here we summarize our current understanding of ribosome biogenesis in archaea and how it might help to further answer evolutionary questions.
Scheduling Parallel and Distributed Processing for Automotive Data Stream Management System
Creators: name: Rho, Jaeyong
name: Azumi, Takuya
name: Nakagawa, Mayo
name: Sato, Kenya
name: Nishio, Nobuhiko
Publisher: name: arXiv
Year: 2017
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: In this paper, to analyze end-to-end timing behavior in heterogeneous processor and network environments accurately, we adopt a heterogeneous selection value on communication contention (HSV_CC) algorithm, which can synchronize tasks and messages simultaneously, for stream processing distribution. In order to adapt HSV_CC to automotive data stream management system (DSMSs), one must address three issues: (i) previous task and message schedules might lead to less efficient resource usages; (ii) the conventional method to determine the task scheduling order may not be best suited to deal with stream processing graphs, and; (iii) there is a need to be able to schedule tasks with time-varying computational requirements efficiently. To address (i), we propose the heterogeneous value with load balancing and communication contention (HVLB_CC) (A) algorithm, which considers load balancing in addition to the parameters considered by the HSV_CC algorithm. We propose HVLB_CC (B) to address issue (ii). HVLB_CC (B) can deal with stream processing task graphs and more various directed acyclic graphs to prevent assigning a higher priority to successor tasks. In addition, to address issue (iii), we propose HVLB_CC_IC. To schedule tasks more efficiently with various computation times, HVLB_CC_IC utilizes schedule holes left in processors. These idle time slots can be used for the execution of an optional part to generate more precise data results by applying imprecise computation models. Experimental results demonstrate that the proposed algorithms improve minimum schedule length, accuracy, and load balancing significantly compared to the HSV_CC algorithm. In addition, the proposed HVLB_CC (B) algorithm can schedule more varied task graphs without reducing performance, and, using imprecise computation models, HVLB_CC_IC yields higher precision data than HVLB_CC without imprecise computation models.
description: Accepted for publication at Journal of Parallel and Distributed Computing (Elsevier) 2017
Studying eventual connectivity issues in Android apps
Creators: name: Escobar-Velasquez, Camilo
name: Mazuera-Rozo, Alejandro
name: Bedoya, Claudia
name: Osorio-Riaño, Michael
name: Linares-Vasquez, Mario
name: Bavota, Gabriele
Publisher: name: Zenodo
Year: 2022

description: Replication package of the paper entitled "Studying eventual connectivity issues in Android apps" published in The Empirical Software Engineering Journal. More Information can be found in its online appendix
On the pure state outcomes of Einstein-Podolsky-Rosen steering
Creators: name: Nguyen, H. Chau
name: Luoma, Kimmo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the Einstein--Podolsky--Rosen experiment, when Alice makes a measurement on her part of a bipartite system, Bob's part is collapsed to, or steered to, a specific ensemble. Moreover, by reading her measurement outcome, Alice can specify which state in the ensemble Bob's system is steered to and with which probability. The possible states that Alice can steer Bob's system to are called steered states. In this work, we study the subset of steered states which are pure after normalisation. We illustrate that these pure steered states, if they exist, often carry interesting information about the shared bipartite state. This information content becomes particularly clear when we study the purification of the shared state. Some applications are discussed. These include a generalisation of the fundamental lemma in the so-called `all-versus-nothing proof of steerability' for systems of arbitrary dimension.
description: 7 pages, 0 figures; corrected typos and terminology
Dissecting van der Waals interactions with Density Functional Theory -- Wannier-basis approach
Creators: name: Dang, Diem Thi-Xuan
name: Le, Dai-Nam
name: Woods, Lilia M.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A new scheme for the computation of dispersive interactions from first principles is presented. This cost-effective approach relies on a Wannier function representation compatible with density function theory descriptions. This is an electronic-based many-body method that captures the full electronic and optical response properties of the materials. It provides the foundation to discern van der Waals and induction energies as well as the role of anisotropy and different stacking patterns when computing dispersive interactions in systems. Calculated results for binding energies in benchmarked materials and layered materials, such as graphite, hBN, and MoS$_2$ give encouraging comparisons with available experimental data. Strategies for broadened computational descriptions of dispersive interactions are also discussed. Our investigation aims at stimulating new experimental studies to measure van der Waals energies in a wider range of materials, especially in layered systems.
description: 29 pages, 1 abstract figure, 5 figures, source codes: 10.6084/m9.figshare.26023024.v2 or https://github.com/Diem-TX-Dang/vdW-MBDWan-code/tree/main, published on Computer Physics Communications