cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Optical variability of the ultracool dwarf TVLM 513-46546: evidence for inhomogeneous dust clouds
Creators: name: Littlefair, S. P.
name: Dhillon, V. S.
name: Marsh, T. R.
name: Shahbaz, T.
name: Martin, E. L.
name: Copperwheat, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present multi-colour photometry of the M8.5V ultracool dwarf "pulsar" TVLM 513-46546 (hereafter TVLM 513) obtained with the triple-beam photometer ULTRACAM. Data were obtained simultaneously in the Sloan-g' and Sloan-i' bands. The previously reported sinusoidal variability, with a period of 2-hrs, is recovered here. However, the Sloan-g' and Sloan-i' lightcurves are anti-correlated, a fact which is incompatible with the currently proposed starspot explanation for the optical variability. The anti-correlated nature and relative amplitudes of the optical lightcurves are consistent with the effects of persistent dust clouds rotating on the surface of the star. In the absence of other plausible explanations for the optical variability of TVLM 513, it seems likely that dust cloud coverage combined with the rapid rotation of TVLM 513 is responsible for the optical variability in this object. However, crude modelling of a photosphere with partial dust cloud coverage shows that the anti-correlation can only be reproduced using cooler models than the literature temperature of TVLM 513. We suggest this discrepancy can be removed if more dust is present within the photosphere of TVLM 513 than theoretical model atmospheres predict, though a definitive statement on this matter will require the development of self-consistent models of partially dusty atmospheres.
description: accepted for publication in MNRAS letters; 6 pages
Learning Dynamical Human-Joint Affinity for 3D Pose Estimation in Videos
Creators: name: Zhang, Junhao
name: Wang, Yali
name: Zhou, Zhipeng
name: Luan, Tianyu
name: Wang, Zhe
name: Qiao, Yu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Graph Convolution Network (GCN) has been successfully used for 3D human pose estimation in videos. However, it is often built on the fixed human-joint affinity, according to human skeleton. This may reduce adaptation capacity of GCN to tackle complex spatio-temporal pose variations in videos. To alleviate this problem, we propose a novel Dynamical Graph Network (DG-Net), which can dynamically identify human-joint affinity, and estimate 3D pose by adaptively learning spatial/temporal joint relations from videos. Different from traditional graph convolution, we introduce Dynamical Spatial/Temporal Graph convolution (DSG/DTG) to discover spatial/temporal human-joint affinity for each video exemplar, depending on spatial distance/temporal movement similarity between human joints in this video. Hence, they can effectively understand which joints are spatially closer and/or have consistent motion, for reducing depth ambiguity and/or motion uncertainty when lifting 2D pose to 3D pose. We conduct extensive experiments on three popular benchmarks, e.g., Human3.6M, HumanEva-I, and MPI-INF-3DHP, where DG-Net outperforms a number of recent SOTA approaches with fewer input frames and model size.
description: Accepted by IEEE Transactions on Image Processing
Clusters' far-reaching influence on narrow-angle tail radio galaxies
Creators: name: de Vos, K
name: Hatch, N. A.
name: Merrifield, M. R.
name: Mingo, B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In order to study the ram-pressure interaction between radio galaxies and the intracluster medium, we analyse a sample of 208 highly-bent narrow-angle tail radio sources (NATs) in clusters, detected by the LOFAR Two-metre Sky Survey. For NATs within $7\,R_{500}$ of the cluster centre, we find that their tails are distributed anisotropically with a strong tendency to be bent radially away from the cluster, which suggests that they are predominantly on radially inbound orbits. Within $0.5\,R_{500}$, we also observe an excess of NATs with their jets bent towards the cluster core, indicating that these outbound sources fade away soon after passing pericentre. For the subset of NATs with spectroscopic redshifts, we find the radial bias in the jet angles exists even out to $10\,R_{500}$, far beyond the virial radius. The presence of NATs at such large radii implies that significant deceleration of the accompanying inflowing intergalactic medium must be occurring there to create the ram pressure that bends the jets, and potentially even triggers the radio source.
description: 5 pages, 4 figures, paper accepted for publication by MNRAS
Hunting the lightest lightest neutralinos
Creators: name: Profumo, Stefano
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The lightest neutralino in the minimal supersymmetric extension of the Standard Model can be, in principle, massless. If super-light neutralinos are the dark matter, structure formation constrains their mass to be above a few keV. We show that relaxing the assumption of radiation domination and entropy conservation prior to Big Bang Nucleosynthesis, the relic abundance of very light neutralinos can be consistent with the inferred cold dark matter density. We study how we can hunt for light neutralino dark matter, with a mass at or below a GeV, focusing on both direct and indirect searches. We argue that the two most promising channels are spin-dependent direct detection and the search for monochromatic gamma rays from the prompt pair-annihilation of neutralinos into photons with GLAST. Our study indicates that the lightest lightest neutralinos can be detected as long as their mass is above a few tenth of a GeV, a mass range where a future linear collider could provide important information on the details of the particle dark matter model.
description: 14 pages, 5 figures, accepted for publication in Phys.Rev.D
title: Front Matter, Table of Contents, Preface, Conference Organization
Creators: name: Barik, Titus
name: Sunshine, Joshua
name: Chasins, Sarah
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2019
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Conference Organization

description: Front Matter, Table of Contents, Preface, Conference Organization
description: OASIcs, Vol. 67, 9th Workshop on Evaluation and Usability of Programming Languages and Tools (PLATEAU 2018), pages 0:i-0:x
Spin memristive systems
Creators: name: Pershin, Yu. V.
name: Di Ventra, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Recently, in addition to the well-known resistor, capacitor and inductor, a fourth passive circuit element, named memristor, has been identified following theoretical predictions. The model example used in such case consisted in a nanoscale system with coupled ionic and electronic transport. Here, we discuss a system whose memristive behaviour is based entirely on the electron spin degree of freedom which allows for a more convenient control than the ionic transport in nanostructures. An analysis of time-dependent spin transport at a semiconductor/ferromagnet junction provides a direct evidence of memristive behaviour. Our scheme is fundamentally different from previously discussed schemes of memristive devices and broadens the possible range of applications of semiconductor spintronics.
An evaluation of the effectiveness of a course in sex role stereotyping and the socialization process
Creators: name: Richardson, Ann
Publisher: name: University of British Columbia
Year: 2010

description: This research study was designed to evaluate the effectiveness of a course in sex role stereotyping in terms of increased awareness and attitudinal changes of the participants. Sex role stereotypes are pervasive and restricting to individuals in Canadian society. As powerful socializing agents, schools can be important facilitators in changing societal notions of sex role standards. This study describes the effects of an interdisciplinary course in socialization and sex role stereotyping for Grades 10 and 11. The study concludes that the course was effective in achieving its stated objectives. The participants increased their awareness of the stereotyping process and perceived the restricting effects of narrowly defined sex roles. The results also showed that the participants perceived the roles of males and females in a more socially androgynous context as compared to the control group.
Political economy of the oil palm value chain in Ghana
Creators: name: Asante, Kofi Takyi
Publisher: name: figshare
Year: 2021
Subjects: subject: 140201 Agricultural Economics
subject: FOS: Economics and business

description: Oil palm (Elaeis guineensis) is of strategic importance to the Ghanaian economy. It is the second most important industrial crop after cocoa and is used widely in local food preparation as well as in industrial processing. In spite of its importance, however, oil palm has consistently underperformed since the early twentieth century. This paper conducts a value chain analysis of the crop, foregrounding the political economy factors that shape the performance of the sector. It draws on a combination of in-depth interviews conducted in March 2020 with a variety of value chain actors and a review of the secondary literature. Additionally, between late May and early June 2020, twelve further interviews were conducted as part of a rapid market survey to assess the impact of the COVID-19 pandemic on the value chain.
Scattering of plasmons at the intersection of two metallic nanotubes: Implications for tunnelling
Creators: name: Mkhitaryan, V. V.
name: Fang, Y.
name: Gerton, J.
name: Mishchenko, E. G.
name: Raikh, M. E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study theoretically the plasmon scattering at the intersection of two metallic carbon nanotubes. We demonstrate that for a small angle of crossing, $θ\ll 1$, the transmission coefficient is an oscillatory function of $λ/θ$, where $λ$ is the interaction parameter of the Luttinger liquid in an individual nanotube. We calculate the tunnel density of states, $ν(ω,x)$, as a function of energy, $ω$, and distance, $x$, from the intersection. In contrast to a single nanotube, we find that, in the geometry of crossed nanotubes, conventional "rapid" oscillations in $ν(ω,x)$ due to the plasmon scattering acquire an aperiodic "slow-breathing" envelope which has $λ/θ$ nodes.
description: 4 pages, 2 figures (revised version)
Imaging of a vibrating object by Sideband Digital Holography
Creators: name: Joud, Fadwa
name: Laloë, Franck
name: Atlan, Michael
name: Hare, Jean
name: Gross, Michel
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We obtain quantitative measurements of the oscillation amplitude of vibrating objects by using sideband digital holography. The frequency sidebands on the light scattered by the object, shifted by n times the vibration frequency, are selectively detected by heterodyne holography, and images of the object are calculated for different orders n. Orders up to n=120 have been observed, allowing the measurement of amplitudes of oscillation that are significantly larger than the optical wavelength. Using the positions of the zeros of intensity for each value of n, we reconstruct the shape of vibration the object.
description: 6 pages
title: Front Matter, Table of Contents, Preface, Conference Organization
Creators: name: Saidi, Selma
name: Ernst, Rolf
name: Ziegenbein, Dirk
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2019
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Conference Organization
subject: General and reference → General literature

description: Front Matter, Table of Contents, Preface, Conference Organization
description: OASIcs, Vol. 68, Workshop on Autonomous Systems Design (ASD 2019), pages 0:i-0:xviii
Evidence of local superconductivity in granular Bi nanowires fabricated by electrodeposition
Creators: name: Tian, Mingliang
name: Kumar, Nitesh
name: Mallouk, Thomas E.
name: Chan, Moses H. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: An unusual enhancement of resistance (i.e., superresistivity) below a certain characteristic temperature Tsr was observed in granular Bi nanowires. This superresistive state was found to be dependent on the applied magnetic field (H) as well as the excitation current (I). The suppression of Tsr by magnetic field resembles that of a superconductor. The observed superresistivity appears to be related to the nucleation of local superconductivity inside the granular nanowire without long-range phase coherence. The phenomenon is reminiscent of the Bose-insulator observed previously in ultra thin two-dimensional (2D) superconducting films and 3D percolative superconducting films.
description: 11 pages, 5 figures. submitted to PRB
Fermi surface dichotomy on systems with fluctuating order
Creators: name: Grilli, M.
name: Seibold, G.
name: Di Ciolo, A.
name: Lorenzana, J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We investigate the effect of a dynamical collective mode coupled with quasiparticles at specific wavevectors only. This coupling describes the incipient tendency to order and produces shadow spectral features at high energies, while leaving essentially untouched the low energy quasiparticles. This allows to interpret seemingly contradictory experiments on underdoped cuprates, where many converging evidences indicate the presence of charge (stripe or checkerboard) order, which remains instead elusive in the Fermi surface obtained from angle-resolved photoemission experiments.
description: 11 pages, 10 figures
The Momentum Kick Model Description of the Near-Side Ridge and Jet Quenching
Creators: name: Wong, Cheuk-Yin
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the momentum kick model, a near-side jet emerges near the surface, kicks medium partons, loses energy, and fragments into the trigger particle and fragmentation products. The kicked medium partons subsequently materialize as the observed ridge particles, which carry direct information on the magnitude of the momentum kick and the initial parton momentum distribution at the moment of jet-(medium parton) collisions. The initial parton momentum distribution extracted from the STAR ridge data for central AuAu collisions at \sqrt{s_{NN}}=200 GeV has a thermal-like transverse momentum distribution and a rapidity plateau structure with a relatively flat distribution at mid-rapidity and sharp kinematic boundaries at large rapidities. Such a rapidity plateau structure may arise from particle production in flux tubes, as color charges and anti-color charges separate at high energies. The centrality dependence of the ridge yield and the degree of jet quenching can be consistently described by the momentum kick model.
description: 28 pages, 10 figures
The WFI Halpha spectroscopic survey of the Magellanic Clouds: Be stars in SMC open clusters
Creators: name: Martayan, Christophe
name: Baade, Dietrich
name: Fabregat, Juan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: At low metallicity, B-type stars show lower loss of mass and, therefore, angular momentum so that it is expected that there are more Be stars in the Magellanic Clouds than in the Milky Way. However, till now, searches for Be stars were only performed in a very small number of open clusters in the Magellanic Clouds. Using the ESO/WFI in its slitless spectroscopic mode, we performed a Halpha survey of the Large and Small Magellanic Cloud. Eight million low-resolution spectra centered on Halpha were obtained. For their automatic analysis, we developed the ALBUM code. Here, we present the observations, the method to exploit the data and first results for 84 open clusters in the SMC. In particular, cross-correlating our catalogs with OGLE positional and photometric data, we classified more than 4000 stars and were able to find the B and Be stars in them. We show the evolution of the rates of Be stars as functions of area density, metallicity, spectral type, and age.
description: talk at IAUS256
Unusual giant magnetoresistance effect in heterojunction structure of ultra-thin single-crystal Pb film on silicon substrate
Creators: name: Wang, Jian
name: Ma, Xu-Cun
name: Qi, Yun
name: Fu, Ying-Shuang
name: Ji, Shuai-hua
name: Lu, Li
name: Xie, X. C.
name: Jia, Jin-Feng
name: Chen, Xi
name: Xue, Qi-Kun
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Superconductor films on semiconductor substrates draw much attention recently since the derived superconductor-based electronics have been shown promising for future data process and storage technologies. By growing atomically uniform single-crystal epitaxial Pb films of several nanometers thick on Si wafers to form a sharp superconductor-semiconductor heterojunction, we have obtained an unusual giant magnetoresistance effect when the Pb film is superconducting. In addition to the great fundamental interest of this effect, the simple structure and compatibility and scalability with current Si-based semiconductor technology offer a great opportunity for integrating superconducting circuits and detectors in a single chip.
description: 14 pages, 3 figures. submitted to APL
Proximity effect and its enhancement by ferromagnetism in high-temperature superconductor-ferromagnet structures
Creators: name: Volkov, A. F.
name: Efetov, K. B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider a bi-layer consisting of a $d-$wave layerd superconductor and diffusive ferromagnet with a domain wall (DW). The $c-$axis in the superconductor and DW in the ferromagnet are assumed to be perpendicular to the interface. We demonstrate that in such a heterostructure the inhomogeneous exchange field enhances the proximity effect. It is shown that, whereas in the absence of the exchange field the $d-$wave condensate decays in the normal metal on the mean free path $l$, the superconductivity penetrates the ferromagnet along the DW over much larger distances. This happens because the presence of DW results in a generation of an odd frequency triplet s-wave component of the condensate. The phenomenon discovered here may help to explain a recent experiment on high temperature superconductor-ferromagnet bi-lyers.
description: 4 pages, 2 figures
Modeling the Variable Polarization of epsilon Aurigae In and Out of Eclipse
Creators: name: Ignace, Richard
name: Henson, Gary
name: Neilson, Hilding
name: Asbury, William
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The eclipsing binary epsilon Aur is unique in being a very long-period binary involving an evolved, variable F star and a suspected B main-sequence star enshrouded in an opaque circumstellar disk. The geometrical arrangement is that the disk is viewed almost perfectly edge-on, with alignment leading to a partial eclipse of the F star. Despite a global observing campaign for the 2009-11 eclipse, there remain outstanding questions about the nature of the binary, its components, the disk, and the evolutionary state of the system. We analyze optical-band polarimetry in conjunction with broad-band color variations to interpret brightness variations across the surface of the F star. We model this both during and after the 1982-84 eclipse for which an extensive and dense data set exists. We develop a model in terms of surface temperature variations characterized by a small global variation overlaid with a temperature variation described with low-order spherical harmonics. While not providing a detailed fit to the dataset, our modeling captures the overall characterization of the color and polarimetric variability. In particular, we are able to recover the gross behavior of the polarimetric excursion in the Q-U plane as observed during eclipse of the F star when compared to post-eclipse behavior.
description: accepted version for Astronomical Journal
A Brief Overview of Results about Uniqueness of the Quantization in Cosmology
Creators: name: Cortez, Jerónimo
name: Marugán, Guillermo A. Mena
name: Velhinho, José M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The purpose of this review is to provide a brief overview of some recent conceptual developments about possible criteria to guarantee the uniqueness of the quantization in a variety of situations that are found in cosmological systems. These criteria impose some conditions on the representation of a group of physically relevant linear transformations. Generally, this group contains any existing symmetry of the spatial sections. These symmetries may or may not be sufficient for the purpose of uniqueness and may have to be complemented with other remaining symmetries that affect the time direction, or with dynamical transformations that in fact are not symmetries. We discuss the extent to which a unitary implementation of the resulting group suffices to fix the quantization, a demand that can be seen as a weaker version of the requirement of invariance. In particular, a strict invariance under certain transformations may eliminate some physically interesting possibilities in the passage to the quantum theory. This is the first review in which this unified perspective is adopted to discuss otherwise rather different uniqueness criteria proposed either in homogeneous loop quantum cosmology or in the Fock quantization of inhomogeneous cosmologies.
description: 24 pages
Identification of electrostatic two-stream instabilities associated with a laser-driven collisionless shock in a multicomponent plasma
Creators: name: Sakawa, Youichi
name: Ohira, Yutaka
name: Kumar, Rajesh
name: Morace, Alessio
name: Doehl, Leonard N. K.
name: Woolsey, Nigel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Electrostatic two-stream instabilities play essential roles in an electrostatic collisionless shock formation. They are a key dissipation mechanism and result in ion heating and acceleration. Since the number and energy of the shock-accelerated ions depend on the instabilities, precise identification of the active instabilities is important. Two-dimensional particle-in-cell simulations in a multicomponent plasma reveal ion reflection and acceleration at the shock front, excitation of a longitudinally propagating electrostatic instability due to a non-oscillating component of the electrostatic field in the upstream region of the shock, and generation of up- and down-shifted velocity components within the expanding-ion components. A linear analysis of the instabilities for a C2H3Cl plasma using the one-dimensional electrostatic plasma dispersion function, which includes electron and ion temperature effects, shows that the most unstable mode is the electrostatic ion-beam two-stream instability (IBTI), which is weakly dependent on the existence of electrons. The IBTI is excited by velocity differences between the expanding protons and carbon-ion populations. There is an electrostatic electron-ion two-stream instability with a much smaller growth rate associated with a population of protons reflecting at the shock. The excitation of the fast-growing IBTI associated with laser-driven collisionless shock increases the brightness of a quasi-monoenergetic ion beam.
Quantum corrections to eta/s
Creators: name: Myers, Robert C.
name: Paulos, Miguel F.
name: Sinha, Aninda
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider corrections to the ratio of the shear viscosity to the entropy density in strongly coupled nonabelian plasmas using the AdS/CFT correspondence. In particular, higher derivative terms with the five-form RR flux, which have been ignored in all previous calculations, are included. This provides the first reliable calculation of the leading order correction in the inverse 't Hooft coupling to the celebrated result eta/s=1/4pi. The leading correction in inverse powers of the number of colours is computed. Our results hold very generally for quiver gauge theories with an internal manifold L_pqr in the holographic dual. Our analysis implies that the thermal properties of these theories will not be affected by the five-form flux terms at this order.
description: 4 pages, RevTex, v3: typos corrected, minor rewording
Educación y pospandemia: tormentas y retos después del COVID-19
Creators: name: Canaza-Choque, Franklin Américo
Publisher: name: figshare
Year: 2021
Subjects: subject: 130302 Comparative and Cross-Cultural Education
subject: FOS: Educational sciences

description: En medio de potentes desafíos y una red de desastres, el impacto de la pandemia del COVID-19 no ha dudado en imponer una poderosa reforma en todo el sistema educativo. No obstante, tales transformaciones de transición y dinámicas disruptivas vienen perfilándose sobre la base de grandes fracturas estructurales, dominantes problemas y retos retenidos. En esa dirección, el presente estudio tiene el propósito de rastrear los principales efectos devenidos de la pandemia durante y después de la interrupción en el plano educativo de Latinoamérica y el Caribe. Para ello, mediante la revisión documental y el análisis presentado por instituciones de alto nivel, la investigación rige dos frentes. Primero, la pandemia llegó en un momento en el que terminó por devorar y deteriorar de manera diferenciada los fijados y modernos estados de bienestar, en particular, uno de los pilares fundamentales del desarrollo social: la educación. Segundo, este mismo efecto ha demandado reparar y remediar un relieve de propósitos pendientes y arrastrados para la educación, que, después de la catástrofe será necesario establecer planes de recuperación, reapertura y de repensar el terreno educativo y empoderar espacios débiles dentro de un nuevo proceso donde la descarga de la pandemia determinará las siguientes décadas.
Supplementary document for Broadband and tunable fiber polarizer based on graphene photonic crystal fiber - 7171477.pdf
Creators: name: Gan, Jiajie
name: Deng, Qingyan
name: Zeng, Zijian
name: Peng, Jiantao
name: Qi, Jinlin
name: Zuo, Yongang
name: Zhou, Xu
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: The SI includes the calculation process of the single-mode structure of Gr-PCF, the software and methods used, the calculation of birefringence coefficient, loss coefficient, and polarization extinction ratio.
Spin-squared Hamiltonian of next-to-leading order gravitational interaction
Creators: name: Steinhoff, Jan
name: Hergt, Steven
name: Schäfer, Gerhard
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The static, i.e., linear momentum independent, part of the next-to-leading order (NLO) gravitational spin(1)-spin(1) interaction Hamiltonian within the post-Newtonian (PN) approximation is calculated from a 3-dim. covariant ansatz for the Hamilton constraint. All coefficients in this ansatz can be uniquely fixed for black holes. The resulting Hamiltonian fits into the canonical formalism of Arnowitt, Deser, and Misner (ADM) and is given in their transverse-traceless (ADMTT) gauge. This completes the recent result for the momentum dependent part of the NLO spin(1)-spin(1) ADM Hamiltonian for binary black holes (BBH). Thus, all PN NLO effects up to quadratic order in spin for BBH are now given in Hamiltonian form in the ADMTT gauge. The equations of motion resulting from this Hamiltonian are an important step toward more accurate calculations of templates for gravitational waves.
description: REVTeX4, 10 pages, v2: minor improvements in the presentation, v3: added omission in Eq. (4) and corrected coefficients in the result, Eq. (9); version to appear in Phys. Rev. D
Spitzer/MIPS 24um Observations of Galaxy Clusters: An Increasing Fraction of Obscured Star-forming Members from z=0.02 to z=0.83
Creators: name: Saintonge, Amélie
name: Tran, Kim-Vy H.
name: Holden, Brad P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the mid-infrared properties of 1315 spectroscopically confirmed members in eight massive (M>5x10^14 Msun) galaxy clusters covering the redshift range from 0.02 to 0.83. The selected clusters all have deep Spitzer MIPS 24um observations, Hubble and ground-based photometry, and extensive redshift catalogs. We observe for the first time an increase in the fraction of cluster galaxies with mid-infrared star formation rates higher than 4 solar masses per year from 3% at z=0.02 to 13% at z=0.83. This increase is reproduced even when considering only the most massive members (Mstars >4x10^10 Msun). The 24 micron observations reveal stronger evolution in the fraction of blue/star-forming cluster galaxies than color-selected samples: the number of red but strongly star-forming cluster galaxies increases with redshift, and combining these with the optically-defined Butcher-Oemler members increases the total fraction of blue/star-forming cluster galaxies to ~30% at z=0.83. These results, the first of our Spitzer/MIPS Infra-Red Cluster Survey (SMIRCS), support earlier studies indicating the increase in star-forming members is driven by cluster assembly and galaxy infall, as is expected in the framework of hierarchical formation.
description: 5 pages, 3 figures. Minor changes since v1 include additional data reduction details - this is the published version of the letter
Effects of non-adiabaticity on the voltage generated by a moving domain wall
Creators: name: Duine, R. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We determine the voltage generated by a field-driven domain wall, taking into account non-adiabatic corrections to the motive force induced by the time-dependent spin Berry phase. Both the diffusive and ballistic transport regimes are considered. We find that that the non-adiabatic corrections, together with the contributions due to spin relaxation, determine the voltage for driving fields smaller than the Walker breakdown limit.
description: 8 pages, 3 figures
Performance evaluation of GAGG(Ce)/LFS scintillator + MPPC array readout with ASIC
Creators: name: Nobashi, Daiki
name: Yamaoka, Kazutaka
name: Tajima, Hiroyasu
name: Ito, Kazuya
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We constructed a gamma-ray detector by combining two types of scintillator array detectors with an MPPC array and evaluated the spectral performance by reading out the signals from the MPPC with a low-power integrated circuit (ASIC) manufactured by IDEAS in Norway. One of the two types of scintillators is a GAGG(Ce) (Ce-doped $ \rm{Gd_3Al_2Ga_3O_{12}}$) scintillator, and the other is an LFS scintillator. The scintillator array is 2.5 cm $\times$ 2.5 cm in size and is coated with $ \rm{BaSO_4}$-based white paint for GAGG(Ce) and an enhanced specular reflector (ESR) for LFS except for the side optically coupled to the MPPC. The spectra derived from the array are affected by the MPPC photon saturations and light leakage from the adjacent pixels, and we carefully corrected for both effects in our data analysis. The energy resolution of 662 keV at 20 $^\circ$C is 6.10$\pm$0.04\% for the GAGG(Ce) scintillator array and 8.57$\pm$0.15\% for the LFS scintillator array, this is equivalent to the typical energy resolution found in the references. The energy resolution depends on the temperature: the energy resolution improves as the temperature decreases. We found that the contribution of thermal noise from the MPPCs to the energy resolution is negligible within the range of --20 to 40 $^\circ$C, and the energy resolution is mainly determined by the light yield of the crystals.
description: 13 pages, 9 figures
Charged 4D Einstein-Gauss-Bonnet Black Hole: Vacuum solutions, Cauchy Horizon, Thermodynamics
Creators: name: Bousder, M.
name: Bourakadi, K. El
name: Bennai, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this paper, we investigate the four-dimensional Einstein-Gauss-Bonnet black hole. The thermodynamic variables and equations of state of black holes are obtained in terms of a new parameterization. We discuss a formulation of the van der Waals equation by studying the effects of the temperature on P-V isotherms. We show the influence of the Cauchy horizon on the thermodynamic parameters. We prove by different methods, that the black hole entropy obey area law (plus logarithmic term that depends on the Gauss-Bonnet coupling α). We propose a physical meaning for the logarithmic correction to the area law. This work can be extended to the extremal EGB black hole, in that case, we study the relationship between compressibility factor, specific heat and the coupling α.
description: 16 pages, 4 figures
Two-Gluon Production and Longitudinal Correlations in the Color Glass Condensate
Creators: name: Fukushima, Kenji
name: Hidaka, Yoshimasa
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We derive an analytical expression for the two-gluon production in the pA (light-heavy) collisions, and focus specifically on the rapidity dependent part. We approximate the gauge field from the heavy target as the Color Glass Condensate which interacts with the light projectile whose source density allows for a perturbative expansion. We discuss the longitudinal correlations of produced particles. Our calculation goes in part beyond the eikonal limit for the emitted gluons so that we can retain the exponential terms with respect to the rapidity difference. Our expression can thus describe the short-range correlations as well as the long-range ones for which our formula is reduced to the known expression. In a special case of two high-pt gluons in the back-to-back kinematics we find that dependence on the rapidity separation is only moderate even in the diagrammatically connected part.
description: 33 pages, 5 figures; some clarification in sec.V added, typos corrected and references added
Ab-initio study of ultrafast spin dynamics in Gdx(FeCo){1-x} alloys
Creators: name: Dewhurst, J. K.
name: Shallcross, Sam
name: Radu, I. E.
name: Elliott, P.
name: Schmising, C. v. Korff
name: Sharma, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using an ultrashort laser pulse we explore {\it ab-initio} the spin dynamics of Gd$_x$(FeCo)$_{1-x}$ at femtosecond time scales. Optical excitations are found to drive charge from Fe majority $d$-states to the unoccupied Gd $f$-minority states, with $f$-electron character excited occupation lagging behind that of the $d$-electron character, leading to substantial demagnetisation of both species while leaving the global moment almost unchanged. For $x > 0.33$ this results in the creation of an ultrafast ferromagnetic (FM) transient by the end of the laser pulse, with the Gd demagnetization rate slower than that of Fe. For all concentrations the Gd moments begin to rotate from their ground state orientations developing in-plane moments of between 0.2-0.5~$μ_B$. Thus, the ultrafast spin dynamics of the material captures three important ingredients of the all optical switching that occurs at much later (picosecond) times: (i) the development of a FM transient, (ii) the different rates of demagnetisation of Fe and Gd and, (iii), the breaking of the colinear symmetry of the ground state. Furthermore, several predictions are made about the behaviour of Fe-Gd alloys that can be experimentally tested and can lead to a spin-filtering device.
DC and high-frequency conductivity of the organic metals beta"-(BEDT-TTF)2SF5RSO3 (R = CH2CF2 and CHF)
Creators: name: Glied, M.
name: Yasin, S.
name: Kaiser, S.
name: Drichko, N.
name: Dressel, M.
name: Wosnitza, J.
name: Schlueter, J. A.
name: Gard, G. L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The temperature dependences of the electric-transport properties of the two-dimensional organic conductors beta"-(BEDT-TTF)2SF5CH2CF2SO3, beta"-(d8-BEDT-TTF)2SF5CH2CF2SO3, and beta"-(BEDT-TTF)2SF5CHFSO3 are measured by dc methods in and perpendicular to the highly-conducting plane. Microwave measurements are performed at 24 and 33.5 GHz to probe the high-frequency behavior from room temperature down to 2 K. Superconductivity is observed in beta"-(BEDT-TTF)2SF5CH2CF2SO3 and its deuterated analogue. Although all the compounds remain metallic down to low-temperatures, they are close to a charge-order transition. This leads to deviations from a simple Drude behavior of the optical conductivity which become obvious already in the microwave range. In beta"-(BEDT-TTF)2SF5CH2CF2SO3, for instance, charge fluctuations cause an increase in microwave resistivity for T < 20 K which is not detected in dc measurements. beta"-(BEDT-TTF)2SF5CHFSO3 exhibits a simple metallic behavior at all frequencies. In the dc transport, however, we observe indications of localization in the perpendicular direction.
description: 8 pages, 9 figures
Spitzer IRAC Infrared Colours of Submillimetre-bright Galaxies
Creators: name: Yun, Min S.
name: Aretxaga, I.
name: Ashby, M. L. N.
name: Austermann, J.
name: Fazio, G. G.
name: Giavalisco, M.
name: Huang, J. -S.
name: Hughes, D. H.
name: Kim, S.
name: Lowenthal, J. D.
name: Perera, T.
name: Scott, K.
name: Wilson, G. W.
name: Younger, J. D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: High-redshift submillimetre-bright galaxies identified by blank field surveys at millimetre and submillimetre wavelengths appear in the region of the IRAC colour-colour diagrams previously identified as the domain of luminous active galactic nuclei (AGNs). Our analysis using a set of empirical and theoretical dusty starburst spectral energy distribution (SED) models shows that power-law continuum sources associated with hot dust heated by young (<100 Myr old), extreme starbursts at z>2 also occupy the same general area as AGNs in the IRAC colour-colour plots. A detailed comparison of the IRAC colours and SEDs demonstrates that the two populations are distinct from each other, with submillimetre-bright galaxies having a systematically flatter IRAC spectrum (>1 mag bluer in the observed [4.5]-[8.0] colour). Only about 20% of the objects overlap in the colour-colour plots, and this low fraction suggests that submillimetre galaxies powered by a dust-obscured AGN are not common. The red IR colours of the submillimetre galaxies are distinct from those of the ubiquitous foreground IRAC sources, and we propose a set of IR colour selection criteria for identifying SMG counterparts that can be used even in the absence of radio or Spitzer MIPS 24 micron data.
description: 9 pages, 4 Postscript figures, uses mn2e.cls. To appear in the Monthly Notices of Royal Astro. Society
Mobility and Economic Impact of COVID-19 Restrictions in Italy using Mobile Network Operator Data
Creators: name: Vespe, Michele
name: Minora, Umberto
name: Iacus, Stefano Maria
name: Spyratos, Spyridon
name: Sermi, Francesco
name: Fontana, Matteo
name: Ciuffo, Biagio
name: Christidis, Panayotis
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Economics (econ.GN)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Economics and business
subject: FOS: Physical sciences

description: This work presents the analysis of the impact of restrictions on mobility in Italy, with a focus on the period from 6 November 2020 to 31 January 2021, when a three-tier system based on different levels of risk was adopted and applied at regional level to contrast the second wave of COVID-19. The impact is first evaluated on mobility using Mobile Network Operator anonymised and aggregate data shared in the framework of a Business-to-Government initiative with the European Commission. Mobility data, alongside additional information about electricity consuption, are then used to assess the impacts on an economic level of the three-tier system in different areas of the country.
An ethological analysis of the communicative behaviour of infant and preschool hearing impaired children
Creators: name: McAlpine, Linda Marjorie
Publisher: name: University of British Columbia
Year: 2010

description: A review of the literature revealed a paucity of research on the communicative behaviour of hearing impaired infant and preschool children. The aim of this investigation was to provide detailed descriptive data on communicative behaviour from which hypotheses could be generated. A second aim was to test the efficacy of Woodward's Method in observing hearing impaired children. Woodward (1977), devised a videotaped Method of analyzing observations which used ethological elements to code behaviour. Behaviour lasting as little as 1/60 of a second could be detected with the equipment used. The Method's procedure for recording data permitted a reliable means of inferring Jakobson's (1960) six Communication Functions, Piagetian stages of cognitive development and Piagetian configurations. The Method was used to sequentially record observations of the communicative behaviour of three hearing impaired infant and preschool girls who were videotaped in their homes as they played and interacted with people. Comparisons to the behaviour of the two normally hearing infants in Woodward's study were made. No generalizations could be made from the comparisons because of the limited sample size in both studies. Comparisons were only made for the purpose of generating hypotheses. The analysis revealed that these three girls used many of the same Elements of Behaviour to communicate a message as the two normally hearing infants in the Woodward study. Two exceptions were noted. The three children in the sample spent more time attempting to communicate in general than the hearing babies and in particular, they used more Phatic communication. Another interesting finding which arose from the recording of the Piagetian configurations was that the three children in the sample appeared to have the same "thought representations" as their hearing peers. The Method also provided a procedure for recording anecdotal data. Information from these data, in addition to the findings from the analysis, generated numerous hypotheses and questions which When submitted to more scientific scrutiny will help in supplying needed data in this relatively unexplored area.
title: Front Matter, Table of Contents, Preface, Conference Organization
Creators: name: Fineman, Jeremy T.
name: Mitzenmacher, Michael
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2019
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Conference Organization

description: Front Matter, Table of Contents, Preface, Conference Organization
description: OASIcs, Vol. 69, 2nd Symposium on Simplicity in Algorithms (SOSA 2019), pages 0:i-0:x
Relation-aware Heterogeneous Graph for User Profiling
Creators: name: Yan, Qilong
name: Zhang, Yufeng
name: Liu, Qiang
name: Wu, Shu
name: Wang, Liang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Retrieval (cs.IR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: User profiling has long been an important problem that investigates user interests in many real applications. Some recent works regard users and their interacted objects as entities of a graph and turn the problem into a node classification task. However, they neglect the difference of distinct interaction types, e.g. user clicks an item v.s.user purchases an item, and thus cannot incorporate such information well. To solve these issues, we propose to leverage the relation-aware heterogeneous graph method for user profiling, which also allows capturing significant meta relations. We adopt the query, key, and value mechanism in a transformer fashion for heterogeneous message passing so that entities can effectively interact with each other. Via such interactions on different relation types, our model can generate representations with rich information for the user profile prediction. We conduct experiments on two real-world e-commerce datasets and observe a significant performance boost of our approach.
description: CIKM2021 Accepted
An orientation for local resource curriculum development
Creators: name: Nerbas, Shaun Frederick
Publisher: name: University of British Columbia
Year: 2010

description: The purpose of this conceptual thesis was to develop a construct for local resource curriculum development which is fundamentally different from Tyler's Rationale. This construct is justified in three ways: 1. It has bases in a particular view of knowledge, and in a view of development derived from that view of knowledge; 2. It was derived from the writer's experience over four years of development and operation of the Mining 11 program at Sparwood, British Columbia; 3. It has potential for generating implications about the development process and knowledge content of curriculum in other resource communities. This thesis describes for teacher/developers an epistemological orientation to the task of local resource curriculum development. The LIMIT SITUATION construct is used to generate implications for resource curriculum development, and seems to avoid many difficulties which are inherently present income, conceptions based on Tyler's Rationale.