cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Three-dimensional radiative transfer models of clumpy tori in Seyfert galaxies
Creators: name: Schartmann, M.
name: Meisenheimer, K.
name: Camenzind, M.
name: Wolf, S.
name: Tristram, K. R. W.
name: Henning, Th.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Tori of Active Galactic Nuclei are made up of a mixture of hot and cold gas, as well as dust. In order to protect the dust grains from destruction by the hot gas as well as by the energetic radiation of the accretion disk, the dust is often assumed to be distributed in clouds. In our new 3D model of AGN dust tori, the torus is modelled as a wedge-shaped disk in which dusty clouds are randomly distributed, by taking the dust density distribution of the corresponding continuous model into account. We especially concentrate on the differences between clumpy and continuous models in terms of the temperature distributions, the surface brightness distributions and interferometric visibilities, as well as spectral energy distributions. To this end, we employ radiative transfer calculations with the help of the 3D Monte Carlo code MC3D. In a second step, interferometric visibilities are calculated from the simulated surface brightness distributions, which can be directly compared to observations with the MIDI instrument. The radial temperature distributions of clumpy models possess significantly enhanced scatter compared to the continuous cases. Even at large distances, clouds can be heated directly by the central accretion disk. The existence of the silicate 10 micron-feature in absorption or in emission depends sensitively on the distribution, the size and optical depth of clouds in the innermost part of the torus, due to shadowing effects of clouds there. This explains failure and success of previous modelling efforts of clumpy tori. After adapting the parameters of our clumpy standard model to the circumstances of the Seyfert 2 Circinus galaxy, it can qualitatively explain recent mid-infrared interferometric observations performed with MIDI, as well as high resolution spectral data.
description: 15 pages, 23 figures, accepted by A&A
How to quantify and avoid finite size effects in computational studies of crystal nucleation: The case of homogeneous crystal nucleation
Creators: name: Hussain, Sarwar
name: Haji-Akbari, Amir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Finite size artifacts arise in molecular simulations of nucleation when critical nuclei are too close to their periodic images. A rigorous determination of what constitutes too close is, however, a major challenge. Recently, we devised rigorous heuristics for detecting such artifacts based on our investigation of how system size impacts the rate of heterogeneous ice nucleation (Hussain, Haji-Akbari, \emph{J. Chem. Phys.} \textbf{154}, 014108, \textbf{2021}). We identified the prevalence of critical nuclei spanning across the periodic boundary, and the thermodynamic and structural properties of the liquid occupying the inter-image region as indicators of finite size artifacts. Here, we further probe the performance of such heuristics by examining the dependence of homogeneous crystal nucleation rates in the Lennard-Jones liquid on system size. The rates depend non-monotonically on system size and vary by almost six orders of magnitude for the range of system sizes considered here. We confirm that the prevalence of spanning critical nuclei is the primary indicator of finite size artifacts and almost fully explains the observed variations in rate. Proximity, or structuring of the inter-image liquid, however, is not as strong of an indicator due to the fragmented nature of crystalline nuclei. As a result, the dependence of rate on system size is subtle for the systems with a minuscule fraction of spanning critical nuclei. These observations indicate that our heuristics are universally applicable to different modes of nucleation (homogeneous and heterogeneous) in different systems even if they might be overly stringent for homogeneous nucleation,~e.g.,~in the LJ system.
description: 10 pages, 5 figures, 1 table
Split Left-Right Symmetry and Scotogenic Quark and Lepton Masses
Creators: name: Ma, Ernest
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A model of split left-right symmetry is proposed, where the first family of quarks and leptons transforms under $SU(2)_R$ but the heavier two families do not. The Higgs scalar sector consists only of an $SU(2)_L$ doublet and an $SU(2)_R$ doublet. The $u,d$ quarks and the electron, as well as the neutrinos, are massless at tree level, but become massive radiatively through their interactions with a simple dark sector. Verifiable consequences include $Z'$ and Higgs properties, neutrino mixing and rare decays, etc.
description: 11 pages, 6 figures
Cloud fragmentation and proplyd-like features in HII regions imaged by HST
Creators: name: De Marco, Orsola
name: O'Dell, C. R.
name: Gelfond, Pamela
name: Rubin, R. H.
name: Glover, S. C. O.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have analyzed HST ACS and WFPC2 new and archival images of eight HII regions to look for new proto-planetary disks (proplyds) similar to those found in the Orion Nebula. We find a wealth of features similar in size (though many are larger) to the bright cusps around the Orion Nebula proplyds. None of them, however, contains a definitive central star. From this, we deduce that the new cusps may not be proplyds, but instead are fragments of molecular cloud material. Out of all the features found in the eight HII regions examined, only one, an apparent edge-on silhouette in M17, may have a central star. This feature might join the small number of bona fide proplyds found outside the Orion Nebula, in M8, M20 and possibly in M16. In line with the results found recently by Smith et al. (2005), the paucity of proplyds outside the Orion Nebula, may be explained by their transient nature as well as by the specific environmental conditions under whichthey can be observed.
description: 51 pages; 19 figures; 5 tables. Accepted by AJ
Collective effects induced by diversity in extended systems
Creators: name: Toral, Raúl
name: Tessone, Claudio J.
name: Lopes, João Viana
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We show that diversity, in the form of quenched noise, can have a constructive effect in the dynamics of extended systems. We first consider a bistable $ϕ^4$ model composed by many coupled units and show that the global response to an external periodic forcing is enhanced under the presence of the right amount of diversity (measured as the dispersion in one of the parameters defining the model). As a second example, we consider a system of active-rotators and show that while they are at rest in the homogeneous case, the disorder introduced by the diversity suffices to trigger the appearance of common firings or pulses. Both effects require very simple ingredients and we expect the results presented here to be of interest in similar models.
description: 8 pages, 4 figures
Characterizing [C II] Line Emission In Massive Star Forming Clumps
Creators: name: Jackson, James M.
name: Allingham, David
name: Killerby-Smith, Nicholas
name: Whitaker, J. Scott
name: Smith, Howard A.
name: Contreras, Yanett
name: Guzman, Andres E.
name: Hogge, Taylor
name: Sanhueza, Patricio
name: Stephens, Ian W.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Because the 157.74 micron [C II] line is the dominant coolant of star-forming regions, it is often used to infer the global star-formation rates of galaxies. By characterizing the [C II] and far-infrared emission from nearby Galactic star-forming molecular clumps, it is possible to determine whether extragalactic [C II] emission arises from a large ensemble of such clumps, and whether [C II] is indeed a robust indicator of global star formation. We describe [C II] and far-infrared observations using the FIFI-LS instrument on the SOFIA airborne observatory toward four dense, high-mass, Milky Way clumps. Despite similar far-infrared luminosities, the [C II] to far-infrared luminosity ratio, L([C II])/L(FIR) varies by a factor of at least 140 among these four clumps. In particular, for AGAL313.576+0.324, no [C II] line emission is detected despite a FIR luminosity of 24,000 L_sun. AGAL313.576+0.324 lies a factor of more than 100 below the empirical correlation curve between L([C II])/L(FIR) and S_ν(63 micron)/S_ν(158 micron) found for galaxies. AGAL313.576+0.324 may be in an early evolutionary "protostellar" phase with insufficient ultraviolet flux to ionize carbon, or in a deeply embedded ``hypercompact' H II region phase where dust attenuation of UV flux limits the region of ionized carbon to undetectably small volumes. Alternatively, its apparent lack of \cii\, emission may arise from deep absorption of the \cii\, line against the 158 micron continuum, or self-absorption of brighter line emission by foreground material, which might cancel or diminish any emission within the FIFI-LS instrument's broad spectral resolution element (~250 km/s)
Wave 0-Trace and length spectrum on convex co-compact hyperbolic manifolds
Creators: name: Guillarmou, Colin
name: Naud, Frederic
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: 58J50, 11F72, 35P25

description: For quotients of the $n+1$-dimensional hyperbolic space by a convex co-compact group $Γ$, we obtain a formula relating the renormalized trace of the wave operator with the resonances of the Laplacian and some conformal invariants of the boundary, generalizing a formula of Guillopé and Zworski in dimension 2. By writing this trace with the length spectrum, we prove precise asymptotics of the number of closed geodesics with an effective, exponentially small error term when the dimension of the limit set of $Γ$ is greater than $n/2$.
description: 13 pages. One typo corrected in the formula of S(s) in proposition 2.2. Already fixed in the published version
Scaling study of dynamical smeared-link clover fermions
Creators: name: Durr, S.
name: Fodor, Z.
name: Hoelbling, C.
name: Hoffmann, R.
name: Katz, S. D.
name: Krieg, S.
name: Kurth, T.
name: Lellouch, L.
name: Lippert, T.
name: Szabo, K. K.
name: Vulvert, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present a framework for phenomenological lattice QCD calculations which makes use of a tree level Symanzink improved action for gluons and stout-link Wilson fermions. We give details of our efficient HMC/RHMC algorithm and present a scaling study of the low-lying N_f=3 baryon spectrum. We find a scaling region that extends to a~<0.16fm and conclude that our action and algorithm are suitable for large scale phenomenological investigations of N_f=2+1 QCD. We expect this conclusion to hold for other comparable actions.
description: 11 pages, 7 figures, aps style. Final published version
Spectral functions and localization landscape theory in speckle potentials
Creators: name: Pelletier, Pierre
name: Delande, Dominique
name: Josse, Vincent
name: Aspect, Alain
name: Mayboroda, Svitlana
name: Arnold, Douglas
name: Filoche, Marcel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Spectral function is a key tool for understanding the behavior of Bose-Einstein condensates of cold atoms in random potentials generated by a laser speckle. In this paper we introduce a new method for computing the spectral functions in disordered potentials. Using a combination of the Wigner-Weyl approach with the landscape theory, we build an approximation for the Wigner distributions of the eigenstates in the phase space and show its accuracy in all regimes, from the deep quantum regime to the intermediate and semiclassical. Based on this approximation, we devise a method to compute the spectral functions using only the landscape-based effective potential. The paper demonstrates the efficiency of the proposed approach for disordered potentials with various statistical properties without requiring any adjustable parameters.
description: 10 pages, 10 figures
An Improved Simulation Model for Pedestrian Crowd Evacuation
Creators: name: Muhammed, Danial A.
name: Rashid, Tarik A.
name: Alsadoon, Abeer
name: Bacanin, Nebojsa
name: Fattah, Polla
name: Mohammadi, Mokhtar
name: Banerjee, Indradip
Publisher: name: arXiv
Year: 2020
Subjects: subject: Multiagent Systems (cs.MA)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: This paper works on one of the most recent pedestrian crowd evacuation models, i.e., "a simulation model for pedestrian crowd evacuation based on various AI techniques", developed in late 2019. This study adds a new feature to the developed model by proposing a new method and integrating it with the model. This method enables the developed model to find a more appropriate evacuation area design, among others regarding safety due to selecting the best exit door location among many suggested locations. This method is completely dependent on the selected model's output, i.e., the evacuation time for each individual within the evacuation process. The new method finds an average of the evacuees' evacuation times of each exit door location; then, based on the average evacuation time, it decides which exit door location would be the best exit door to be used for evacuation by the evacuees. To validate the method, various designs for the evacuation area with various written scenarios were used. The results showed that the model with this new method could predict a proper exit door location among many suggested locations. Lastly, from the results of this research using the integration of this newly proposed method, a new capability for the selected model in terms of safety allowed the right decision in selecting the finest design for the evacuation area among other designs.
description: 15 pages, accepted in Mathematics, MDPI, 2020
Crystal-field states in NaCoO2 and in wet cobalt superconductors (NaxCoO2)
Creators: name: Ropka, R. J. Radwanski Z.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We claim that for calculations of the electronic structure of 3d oxides very strong electron correlations have to be taken into account similarly to those assumed in many-electron crystal field approach. For Co3+ ions in NaxCoO2.yH2O there are 15 low lying many-electron states within 0.1 eV as can be obtained in the many-electron CEF approach with taking into account the spin-orbit coupling. We claim, that the used by us Hamiltonian for the trigonal distortion is correct.
description: 4 pages, 3 fig embeded
Black Holes LIGO/Virgo Domination and Single-lined Binaries with a Black Hole Candidate Component
Creators: name: Lipunov, Vladimir
name: Gorbovskoy, Evgeny
name: Grinshpun, Valeria
name: Vlasenko, Daniil
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this letter, we note that the observed in the LIGO / Virgo experiment ratio of the detection rate of black holes to the rate of detection of binary neutron stars requires the assumption of a "conservative" collapse of massive stars into a black hole: almost all the mass of the collapsing star goes under the horizon. This is consistent with the large masses of black holes detected by LIGO/Virgo. On the other hand, the assumption of a small loss of matter during the collapse into a black hole is in good agreement with the small eccentricity of Single-lined Binaries. At the same time, the absence of X-rays from most black holes in binary systems with blue stars is explained. We argue that three sets of LIGO / Virgo observations and data on the Single-lined Binary with a Candidate Black Hole Component confirm the scenario of the evolution of massive field binaries.
description: 15 pages, 3 figures. MNRAS accepted
Spin gaps in two models of strongly correlated electron systems
Creators: name: Sikkema, Arnold Eric
Publisher: name: University of British Columbia
Year: 2009

description: Two aspects of strongly correlated electron systems are studied in this thesis. Hubbard-type models are thought to be at the basis of high-critical-temperature superconductivity. One interaction which has not had much study is the nearest-neighbour hopping of on-site singlet pairs. We refine earlier renormalization group arguments and, using the density-matrix renormalization group method, numerically confirm their prediction that a spin gap opens at infinitesimal pair-hopping amplitude V > 0 in the one-dimensional tight-binding model. We also find a phase separation transition at a finite V > 0 as well as a spin-gap transition at a finite V < 0. The exotic magnetic behaviour of heavy-fermion materials involves an interplay between the screening of local moments from each other and the formation of a magnetic state of long range order. While the single-impurity Kondo Hamiltonian is thought to model some aspects of this behaviour, the properties of the Kondo lattice model away from half-filling are largely unknown. We determine the presence of a spin-gap region in the phase diagram of the one-dimensional Heisenberg-Kondo lattice model and make predictions about certain concealed dimerization order parameters.
Pulsed multireservoir engineering for a trapped ion with applications to state synthesis and quantum Otto cycles
Creators: name: Teixeira, Wallace S.
name: Keller, Matthias K.
name: Semião, Fernando L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Conducting an open quantum system towards a desired steady state through reservoir engineering is a remarkable task that takes dissipation and decoherence as tools rather than impediments. Here we develop a collisional model to implement reservoir engineering for the one-dimensional harmonic motion of a trapped ion. Our scheme is based on the pulsed interaction between the vibrational mode and the electronic levels of a trapped ion, which is promoted by resolved-sideband lasers. Having multiple internal levels, we show that multiple reservoirs can be engineered, allowing for more efficient synthesis of well-known non-classical states of motion and the generation of states that are unfeasible with a single-bath setup, for instance, thermal states with arbitrary positive temperatures. We apply these ideas to quantum Otto cycles beyond purely thermal reservoirs. In particular, we present general conditions for the violation of the standard Otto bound in the limiting regime of non-adiabatic dynamics.
description: 22 pages, 7 figures. Published in New Journal of Physics
Discovery of $δ$ Scuti pulsation in the Herbig Ae star VV Ser
Creators: name: Ripepi, V.
name: Bernabei, S.
name: Marconi, M.
name: Ruoppo, A.
name: Palla, F.
name: Monteiro, M. J. P. F. G.
name: Marques, J. P.
name: Ferrara, P.
name: Marinoni, S.
name: Terranegra, L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A new observational study of the Herbig Ae star VV Ser has been performed in order to detect and accurately measure pulsation frequencies in the $δ$ Scuti range. As it belongs to the continuous field of view of the asteroseismological satellite COROT, this study also aims at characterizing the properties of VV Ser as a potential ``COROT additional program'' candidate. CCD time series photometry in the Johnson V filter has been obtained during three consecutive years. The resulting light curves have been subject to detailed frequency analysis and the derived frequencies have been compared to model predictions. Seven pulsation frequencies have been measured on the basis of the best dataset obtained in 2004, ranging from $\sim$ 31 to $\sim$ 118 $μHz$, with an accuracy of the order of 0.5 $μHz$. The comparison with an extensive set of asteroseismological models shows that all the observed periodicities can be reproduced if the stellar mass is close to $4 M_{\odot}$. Conversely, the measured frequencies can be associated to $p$ modes only if the effective temperature is significantly lower than that obtained from the spectral type conversion. The present results seem to suggest that more accurate spectral type determination is necessary in order to discriminate the best fit model solution. In any case, the stellar mass of VV Ser is close to the upper mass limit ($\sim 4 M_{\odot}$) for this class of pulsators.
description: A&A Accepted, 10 pages + 4 pages online material
Letter from J.E. McAllister to Jim [James Goldie], February 26, 1911
Creators: name: McAllister, John Edgar
Publisher: name: The University of British Columbia
Year: 2017

description: Letter to James Goldie from J.E. McAllister, dated February 26, 1911, regarding inquiry about condition of Bellevue Ranche and possible sale for $60, 000.
Fermi resonance in the Raman spectrum of graphene
Creators: name: Kalita, Dipankar
name: Amato, Michele
name: Artaud, Alexandre
name: Marty, Laëtitia
name: Bouchiat, Vincent
name: Coraux, Johann
name: Brouder, Christian
name: Lazzeri, Michele
name: Bendiab, Nedjma
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report the observation of an intense anomalous peak at 1608 cm$^{-1}$ in the Raman spectrum of graphene associated to the presence of chromium nanoparticles in contact with graphene. Bombardment with an electron beam demonstrates that this peak is distinct from the well studied D$'$ peak appearing as defects are created in graphene; the new peak is found non dispersive. We argue that the bonding of chromium atoms with carbon atoms softens the out-of-plane optical (ZO) phonon mode, in such a way that the frequency of its overtone decreases to $2ω_{\rm ZO}\simω_{\rm G}$, where $ω_{\rm G}$=1585~cm$^{-1}$ is the frequency of the Raman-active E$_{\rm 2g}$ mode. Thus, the observed new peak is attributed to the 2ZO mode which becomes Raman-active following a mechanism known as Fermi resonance. First-principles calculations on vibrational and anharmonic properties of the graphene/Cr interface support this scenario.
description: 12 pages, 10 figures
Nonsmoothable, locally indicable group actions on the interval
Creators: name: Calegari, Danny
Publisher: name: arXiv
Year: 2008
Subjects: subject: Dynamical Systems (math.DS)
subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 37C85; 37E05

description: By the Thurston stability theorem, a group of C^1 orientation-preserving diffeomorphisms of the closed unit interval is locally indicable. We show that the local order structure of orbits gives a stronger criterion for nonsmoothability that can be used to produce new examples of locally indicable groups of homeomorphisms of the interval that are not conjugate to groups of C^1 diffeomorphisms.
description: 4 pages, 1 figure
The Relationship of Organizational Structure, Performance, and the Type of Technology
Creators: name: Zeller, Donna
Publisher: name: Zenodo
Year: 2021
Subjects: Organizational Structure
Organizational Performance
Type of Technology
Joan Woodward
Contingency Theorist
Strategic Human Resource Management

description: In the book, Industrial Organization: Theory and Practice (1965), Joan Woodward presents a comparative empirical study of manufacturing organizations in England. Primarily, Woodward found that the relationship of organizational structure and performance surfaced only by the introduction of an extra variable: the type of technology. The aim of this article is to present the influence of technology on organizational structure and performance in today’s hybrid (virtual offsite / traditional ‘brick and mortar’) workplace; through the lens of Woodward’s Industrial Organization: Theory and Practice (1965). 
Exact and Approximate Unitary 2-Designs: Constructions and Applications
Creators: name: Dankert, Christoph
name: Cleve, Richard
name: Emerson, Joseph
name: Livine, Etera
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We develop the concept of a unitary t-design as a means of expressing operationally useful subsets of the stochastic properties of the uniform (Haar) measure on the unitary group U(2^n) on n qubits. In particular, sets of unitaries forming 2-designs have wide applicability to quantum information protocols. We devise an O(n)-size in-place circuit construction for an approximate unitary 2-design. We then show that this can be used to construct an efficient protocol for experimentally characterizing the fidelity of a quantum process on n qubits with quantum circuits of size O(n) without requiring any ancilla qubits, thereby improving upon previous approaches.
description: 7 pages, updating to version published in 2009
Current-induced spin torques on single GdFeCo magnetic layers
Creators: name: Céspedes-Berrocal, David
name: Damas, Heloïse
name: Petit-Watelot, Sébastien
name: Maccariello, David
name: Tang, Ping
name: Arriola-Córdova, Aldo
name: Vallobra, Pierre
name: Xu, Yong
name: Bello, Jean-Loïs
name: Martin, Elodie
name: Migot, Sylvie
name: Ghanbaja, Jaafar
name: Zhang, Shufeng
name: Hehn, Michel
name: Mangin, Stéphane
name: Panagopoulos, Christos
name: Cros, Vincent
name: Fert, Albert
name: Rojas-Sánchez, Juan-Carlos
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Spintronics exploits spin-orbit coupling (SOC) to generate spin currents, spin torques, and, in the absence of inversion symmetry, Rashba, and Dzyaloshinskii-Moriya interactions (DMI). The widely used magnetic materials, based on 3d metals such as Fe and Co, possess a small SOC. To circumvent this shortcoming, the common practice has been to utilize the large SOC of nonmagnetic layers of 5d heavy metals (HMs), such as Pt, to generate spin currents by Spin Hall Effect (SHE) and, in turn, exert spin torques on the magnetic layers. Here, we introduce a new class of material architectures, excluding nonmagnetic 5d HMs, for high-performance spintronics operations. We demonstrate very strong current-induced torques exerted on single GdFeCo layers due to the combination of large SOC of the Gd 5d states, and inversion symmetry breaking mainly engineered by interfaces. These "self-torques" are enhanced around the magnetization compensation temperature (close to room temperature) and can be tuned by adjusting the spin absorption outside the GdFeCo layer. In other measurements, we determine the very large emission of spin current from GdFeCo. This material platform opens new perspectives to exert "self-torques" on single magnetic layers as well as to generate spin currents from a magnetic layer.
description: 26 pages, 4 figures plus 5 pages of sup. information
Geodesic currents and length compactness for automorphisms of free groups
Creators: name: Francaviglia, Stefano
Publisher: name: arXiv
Year: 2006
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 20F36; 20E36

description: We prove a compactness theorem for automorphisms of free groups. Namely, we show that the set of automorphisms keeping bounded the length of the uniform current is compact (up to conjugation.) This implies that the spectrum of the length of the images of the uniform current is discrete, answering to a conjecture of I. Kapovich.
description: Changes from v1: the proof of main theorem is a little different; added a section with generalisations. This is the version accepted for pubblication
Joannes Hus redivivus - die Blüte des tschechischen ökumenischen Frühlings
Creators: name: Svatoň, Robert
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 64 Nr. 3 (2015): Ökumenische Rundschau, Band 64, Heft 3
Global well-posedness for the KP-I equation on the background of a non localized solution
Creators: name: Molinet, Luc
name: Saut, Jean-Claude
name: Tzvetkov, Nikolay
Publisher: name: arXiv
Year: 2006
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q53, 35Q51, 35A05

description: We prove that the Cauchy problem for the KP-I equation is globally well-posed for initial data which are localized perturbations (of arbitrary size) of a non-localized (i.e. not decaying in all directions) traveling wave solution (e.g. the KdV line solitary wave or the Zaitsev solitary waves which are localized in $x$ and $y$ periodic or conversely).
FLEx project backup for community members
Creators: name: Butler, Lynnika
name: Geary, Quirina
name: Warner, Natasha
name: Van Volkinburg, Heather
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: css

description: 1 FWBACKUP file. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/). If you wish to cite this material or use it for additional analyses or publications, please attempt to contact a member of the Mutsun community, starting with co-author Quirina Geary (qgeary@tamien.org). This is not for permission, but to keep the community informed of what is being published about them.
Non-Invasive Near-field Spectroscopy of Single Sub-Wavelength Complementary Resonators
Creators: name: Hale, Lucy L
name: Keller, Janine
name: Siday, Thomas
name: Hermans, Rodolfo I
name: Haase, Johannes
name: Reno, John L
name: Brener, Igal
name: Scalari, Giacomo
name: Faist, Jérôme
name: Mitrofanov, Oleg
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Subwavelength metallic resonators provide a route to achieving strong light-matter coupling by means of tight confinement of resonant electromagnetic fields. Investigation of such resonators however often presents experimental difficulties, particularly at terahertz (THz) frequencies. A single subwavelength resonator weakly interacts with THz beams, making it difficult to probe it using far-field methods; whereas arrays of resonators exhibit inter-resonator coupling, which affects the resonator spectral signature and field confinement. Here, traditional far-field THz spectroscopy is systematically compared with aperture-type THz near-field microscopy for investigating complementary THz resonators. Whilst the far-field method proves impractical for measuring single resonators, the near-field technique gives high signal-to-noise spectral information, only achievable in the far-field with resonator arrays. At the same time, the near-field technique allows us to analyze single resonators - free from inter-resonator coupling present in arrays - without significant interaction with the near-filed probe. Furthermore, the near-field technique allows highly confined fields and surface waves to be mapped in space and time. This information gives invaluable insight into resonator spectral response in arrays. This near-field microscopy and spectroscopy method enables investigations of strong light-matter coupling at THz frequencies in the single-resonator regime.
description: 29 pages, 8 figures
The Magnetohydrodynamics of Shock-Cloud Interaction in Three Dimensions
Creators: name: Shin, Min-Su
name: Stone, James M.
name: Snyder, Gregory F.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The magnetohydrodynamic evolution of a dense spherical cloud as it interacts with a strong planar shock is studied, as a model for shock interactions with density inhomogeneities in the interstellar medium. The cloud is assumed to be small enough that radiative cooling, thermal conduction, and self-gravity can be ignored. A variety of initial orientations (including parallel, perpendicular, and oblique to the incident shock normal) and strengths for the magnetic field are investigated. During the early stages of the interaction (less than twice the time taken for the transmitted shock to cross the interior of the cloud) the structure and dynamics of the shocked cloud is fairly insensitive to the magnetic field strength and orientation. However, at late times strong fields substantially alter the dynamics of the cloud, suppressing fragmentation and mixing by stabilizing the interface at the cloud surface. Even weak magnetic fields can drastically alter the evolution of the cloud compared to the hydrodynamic case. Weak fields of different geometries result in different distributions and amplifications of the magnetic energy density, which may affect the thermal and non-thermal x-ray emission expected from shocked clouds associated with, for example, supernovae remnants.
description: Accepted for publication in Astrophysical Journal; a higher resolution file can be found at http://www.astro.princeton.edu/~msshin/science/shock_cloud.pdf.gz
TJU-DHD: A Diverse High-Resolution Dataset for Object Detection
Creators: name: Pang, Yanwei
name: Cao, Jiale
name: Li, Yazhao
name: Xie, Jin
name: Sun, Hanqing
name: Gong, Jinfeng
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Vehicles, pedestrians, and riders are the most important and interesting objects for the perception modules of self-driving vehicles and video surveillance. However, the state-of-the-art performance of detecting such important objects (esp. small objects) is far from satisfying the demand of practical systems. Large-scale, rich-diversity, and high-resolution datasets play an important role in developing better object detection methods to satisfy the demand. Existing public large-scale datasets such as MS COCO collected from websites do not focus on the specific scenarios. Moreover, the popular datasets (e.g., KITTI and Citypersons) collected from the specific scenarios are limited in the number of images and instances, the resolution, and the diversity. To attempt to solve the problem, we build a diverse high-resolution dataset (called TJU-DHD). The dataset contains 115,354 high-resolution images (52% images have a resolution of 1624$\times$1200 pixels and 48% images have a resolution of at least 2,560$\times$1,440 pixels) and 709,330 labeled objects in total with a large variance in scale and appearance. Meanwhile, the dataset has a rich diversity in season variance, illumination variance, and weather variance. In addition, a new diverse pedestrian dataset is further built. With the four different detectors (i.e., the one-stage RetinaNet, anchor-free FCOS, two-stage FPN, and Cascade R-CNN), experiments about object detection and pedestrian detection are conducted. We hope that the newly built dataset can help promote the research on object detection and pedestrian detection in these two scenes. The dataset is available at https://github.com/tjubiit/TJU-DHD.
description: object detection and pedestrian detection. website: https://github.com/tjubiit/TJU-DHD
Tame homomorphisms of polytopal rings
Creators: name: Erlandsson, Viveka
Publisher: name: arXiv
Year: 2006
Subjects: subject: Commutative Algebra (math.AC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 13F99, 14M25

description: The object of this paper is the tameness conjecture which describes an arbitrary graded k-algebra homomorphism of polytopal rings. We give further evidence of this conjecture by showing supporting results concerning joins, multiples and products of polytopes.
Addendum to ``Decoupling of pion coupling $f_π$ from quarks at high density in three models, and its possible observational consequences"
Creators: name: Bagchi, Manjari
name: Sinha, Monika
name: Dey, Mira
name: Dey, Jishnu
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The pions decouple from quarks while their coupling to nucleons $g_{πNN}$ remains unchanged at high density. This will have consequences for some recent papers.
description: Addendum to hep-ph/0505139 [Phys. Lett. B 618 (2005) 115, DOI: 10.1016/j.physletb.2005.05.031]
Magnetization dynamics in dysprosium orthoferrites via inverse Faraday effect
Creators: name: Perroni, C. A.
name: Liebsch, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The ultrafast non-thermal control of magnetization has recently become feasible in canted antiferromagnets through photomagnetic instantaneous pulses [A.V. Kimel {\it et al.}, Nature {\bf 435}, 655 (2005)]. In this experiment circularly polarized femtosecond laser pulses set up a strong magnetic field along the wave vector of the radiation through the inverse Faraday effect, thereby exciting non-thermally the spin dynamics of dysprosium orthoferrites. A theoretical study is performed by using a model for orthoferrites based on a general form of free energy whose parameters are extracted from experimental measurements. The magnetization dynamics is described by solving coupled sublattice Landau-Lifshitz-Gilbert equations whose damping term is associated with the scattering rate due to magnon-magnon interaction. Due to the inverse Faraday effect and the non-thermal excitation, the effect of the laser is simulated by magnetic field Gaussian pulses with temporal width of the order of hundred femtoseconds. When the field is along the z-axis, a single resonance mode of the magnetization is excited. The amplitude of the magnetization and out-of-phase behavior of the oscillations for fields in z and -z directions are in good agreement with the cited experiment. The analysis of the effect of the temperature shows that magnon-magnon scattering mechanism affects the decay of the oscillations on the picosecond scale. Finally, when the field pulse is along the x-axis, another mode is excited, as observed in experiments. In this case the comparison between theoretical and experimental results shows some discrepancies whose origin is related to the role played by anisotropies in orthoferrites.
description: 10 pages, 6 figures
Structure of graphene and a surface carbide grown on the (0001) surface of rhenium
Creators: name: Mazaleyrat, Estelle
name: Pozzo, Monica
name: Alfè, Dario
name: Artaud, Alexandre
name: Herrero, Ana Cristina Gómez
name: Lisi, Simone
name: Guisset, Valérie
name: David, Philippe
name: Chapelier, Claude
name: Coraux, Johann
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Transition metal surfaces catalyse a broad range of thermally-activated reactions involving carbon-containing-species -- from atomic carbon to small hydrocarbons or organic molecules, and polymers. These reactions yield well-separated phases, for instance graphene and the metal surface, or, on the contrary, alloyed phases, such as metal carbides. Here, we investigate carbon phases on a rhenium (0001) surface, where the former kind of phase can transform into the latter. We find that this transformation occurs with increasing annealing time, which is hence not suitable to increase the quality of graphene. Our scanning tunneling spectroscopy and reflection high-energy electron diffraction analysis reveal that repeated short annealing cycles are best suited to increase the lateral extension of the structurally coherent graphene domains. Using the same techniques and with the support of density functional theory calculations, we next unveil, in real space, the symmetry of the many variants (two six-fold families) of a rhenium surface carbide observed with diffraction since the 1970s, and finally propose models of the atomic details. One of these models, which nicely matches the microscopy observations, consists of parallel rows of eight aligned carbon trimers with a so-called $(7\times\sqrt{\mathrm{19}})$ unit cell with respect to Re(0001).
description: 12 pages, 6 figures
C-SAW: A Framework for Graph Sampling and Random Walk on GPUs
Creators: name: Pandey, Santosh
name: Li, Lingda
name: Hoisie, Adolfy
name: Li, Xiaoye S.
name: Liu, Hang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Many applications require to learn, mine, analyze and visualize large-scale graphs. These graphs are often too large to be addressed efficiently using conventional graph processing technologies. Many applications have requirements to analyze, transform, visualize and learn large scale graphs. These graphs are often too large to be addressed efficiently using conventional graph processing technologies. Recent literatures convey that graph sampling/random walk could be an efficient solution. In this paper, we propose, to the best of our knowledge, the first GPU-based framework for graph sampling/random walk. First, our framework provides a generic API which allows users to implement a wide range of sampling and random walk algorithms with ease. Second, offloading this framework on GPU, we introduce warp-centric parallel selection, and two optimizations for collision migration. Third, towards supporting graphs that exceed GPU memory capacity, we introduce efficient data transfer optimizations for out-of-memory sampling, such as workload-aware scheduling and batched multi-instance sampling. In its entirety, our framework constantly outperforms the state-of-the-art projects. First, our framework provides a generic API which allows users to implement a wide range of sampling and random walk algorithms with ease. Second, offloading this framework on GPU, we introduce warp-centric parallel selection, and two novel optimizations for collision migration. Third, towards supporting graphs that exceed the GPU memory capacity, we introduce efficient data transfer optimizations for out-of-memory and multi-GPU sampling, such as workload-aware scheduling and batched multi-instance sampling. Taken together, our framework constantly outperforms the state of the art projects in addition to the capability of supporting a wide range of sampling and random walk algorithms.
description: 12 pages,IEEE Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC20)
A avaliação da investigação e a Ciência Aberta
Creators: name: Peres Menezes, Débora
Publisher: name: Zenodo
Year: 2024

description: Apresentação realizada no Painel "A avaliação da investigação e a Ciência aberta, da 15ª Conferência Lusófona de Ciência Aberta, na Escola Superior de Enfermagem do Porto (ESEP), de 01 a 04 de outubro de 2024.
Variable-range Projection Model for Turbulence-driven Collisions
Creators: name: Gustavsson, K.
name: Mehlig, B.
name: Wilkinson, M.
name: Uski, V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We discuss the probability distribution of relative speed $ΔV$ of inertial particles suspended in a highly turbulent gas when the Stokes numbers, a dimensionless measure of their inertia, is large. We identify a mechanism giving rise to the distribution $P(ΔV) \sim \exp(-C |ΔV|^{4/3})$ (for some constant $C$). Our conclusions are supported by numerical simulations and the analytical solution of a model equation of motion. The results determine the rate of collisions between suspended particles. They are relevant to the hypothesised mechanism for formation of planets by aggregation of dust particles in circumstellar nebula.
description: 4 pages, 2 figures
We Need to Rethink How We Describe and Organize Spatial Information: Instrumenting and Observing the Community of Users to Improve Data Description and Discovery
Creators: name: Adams, Benjamin
name: Gahegan, Mark
Publisher: name: arXiv
Year: 2020
Subjects: subject: Social and Information Networks (cs.SI)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: In Spatial Data Infrastructure or Cyber Infrastructure, the description of geographic data semantics is intended to support data discovery, reuse and integration. In the vast majority of cases the producers of these data generate descriptions based on particular understandings of what uses the data are good for. This producer-oriented perspective means that the descriptions often do not help to answer the question of whether a data set is of use for a consumer who might want to apply it in a different context. In this paper, we discuss the role geographic information observatories can play in providing an infrastructure for observing the context of data use by consumers. These observations of data pragmatics lead to operational statistical methods that will support better fitness-for-use assessment. Finally, we highlight some of the challenges to building these observatories, and briefly discuss strategies to address those challenges.
description: 6 pages, 2 figures
FLEx project backup for the public
Creators: name: Butler, Lynnika
name: Geary, Quirina
name: Warner, Natasha
name: Van Volkinburg, Heather
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: css

description: 1 FWBACKUP file. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/). If you wish to cite this material or use it for additional analyses or publications, please attempt to contact a member of the Mutsun community, starting with co-author Quirina Geary (qgeary@tamien.org). This is not for permission, but to keep the community informed of what is being published about them.