cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Atomic hypothesis: Physical consequences
Creators: name: Rivas, Martin
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: The hypothesis that matter is made of some ultimate and indivisible objects, together the restricted relativity principle, establishes a constraint on the kind of variables we are allowed to use for the variational description of elementary particles. We consider that the atomic hypothesis not only states the indivisibility of elementary particles, but also that these ultimate objects, if not annihilated, cannot be modified by any interaction so that all allowed states of an elementary particle are only kinematical modifications of any one of them. Terefore, an elementary particle cannot have excited states. In this way, the kinematical group of spacetime symmetries not only defines the symmetries of the system, but also the variables in terms of which the mathematical description of the elementary particles can be expressed in either the classical or the quantum mechanical description. When considering the interaction of two Dirac particles, the atomic hypothesis restricts the interaction Lagrangian to a kind of minimal coupling interaction.
description: Accepted final version in J. Phys. A Math and Theor
Invariant quantities in shear flow
Creators: name: Baule, A.
name: Evans, R. M. L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The dynamics of systems out of thermal equilibrium is usually treated on a case-by-case basis without knowledge of fundamental and universal principles. We address this problem for a class of driven steady states, namely those mechanically driven at the boundaries such as complex fluids under shear. From a nonequilibrium counterpart to detailed balance (NCDB) we derive a remarkably simple set of invariant quantities which remain unchanged when the system is driven. These new nonequilibrium relations are both exact and valid arbitrarily far from equilibrium. Furthermore, they enable the systematic calculation of transition rates in driven systems with state-spaces of arbitrary connectivity.
description: 4 pages, 2 figures
Charged hadron multiplicity fluctuations in Au+Au and Cu+Cu collisions from sqrt(s_NN) = 22.5 to 200 GeV
Creators: name: Adare, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for non-dynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. An analysis of Negative Binomial Distribution fits to the multiplicity distributions demonstrates that the heavy ion data exhibit weak clustering properties.
description: 464 authors from 60 institutions, 17 pages, 12 figures, 1 table. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.html
Diamagnetism around the Meissner transition in a homogeneous cuprate single crystal
Creators: name: Mosqueira, J.
name: Cabo, L.
name: Vidal, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The in-plane diamagnetism around the Meissner transition was measured in a Tl$_2$Ba$_2$Ca$_2$Cu$_3$O$_{10}$ single crystal of high chemical and structural quality, which minimizes the inhomogeneity and disorder rounding effects on the magnetization. When analyzed quantitatively and consistently above and below the transition in terms of the Ginzburg-Landau (GL) approach with fluctuations of Cooper pairs and vortices, these data provide a further confirmation that the observed Meissner transition is a conventional GL superconducting transition in a homogeneous layered superconductor.
description: 5 pages, including 3 figures
The VLA Survey of the Chandra Deep Field South. II. Identification and host galaxy properties of submillijansky sources
Creators: name: Mainieri, V.
name: Kellermann, K. I.
name: Fomalont, E. B.
name: Miller, N.
name: Padovani, P.
name: Rosati, P.
name: Shaver, P.
name: Silverman, J.
name: Tozzi, P.
name: Bergeron, J.
name: Hasinger, G.
name: Norman, C.
name: Popesso, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field South (Kellermann et al. 2008). Using deep i-band Advanced Camera for Surveys, R-band Wide Field Imager, K-band SOFI/NTT, K-band ISAAC/VLT and Spitzer imaging data, we are able to find reliable counterparts for 254 (~95%) VLA sources. Twelve radio sources remain unidentified and three of them are ``empty fields''. Using literature and our own data we are able to assign redshifts to 186 (~70%) radio sources: 108 are spectroscopic redshifts and 78 reliable photometric redshifts. Based on the rest frame colors and morphological distributions of the host galaxies we find evidences for a change in the submillijansky radio source population: a) above ~ 0.08 mJy early-type galaxies are dominating; b) at flux densities below ~0.08 mJy, starburst galaxies become dominant.
description: To appear in ApJS, 50 pages with 15 figures, an ASCII varsion of Table 3 and a version with higher resolution figures are available at http://taltos.pha.jhu.edu/~nmiller/vlaecdfs_main.html
Charmonium singlets, open charm and exotic hadrons
Creators: name: Richard, J. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Caution is suggested on the comparison of the spin-singlet charmonium P-state with the centre of gravity of triplet states, when the mass splitting is of the order of a few MeV. The physics of new hidden-charm states X and Y is briefly reviewed. Perspectives for producing double-charm baryons and double-charm exotic mesons are discussed.
description: Talk given at the DIS 2007 Conference, Munich Germany, April 2007 - To be published in the proceedings - Typos corrected, references added
On higher-power moments of $Δ(x)$(III)
Creators: name: Zhai, Wenguang
Publisher: name: arXiv
Year: 2008
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11N37, 11M06

description: Let $Δ(x)$ be the error term of the Dirichlet divisor problem. An asymptotic formula with the error term $O(T^{53/28+ε})$ is established for the integral $\int_1^TΔ^4(x)dx.$ Similar results are also established for some other well-known error terms in the analytic number theory .
description: 21 Pages
Non-binary Snow Index for Multi-Component Surfaces
Creators: name: Arreola-Esquivel, Mario M.
name: Toxqui-Quitl, Carina
name: Delgadillo-Herrera, Maricela
name: Padilla-Vivanco, Alfonso
name: Ortega-Mendoza, José G.
name: Carbone, Anna
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: A Non-Binary Snow Index for Multi-Component Surfaces (NBSI-MS) is proposed to map snow/ice cover. The NBSI-MS is based on the spectral characteristics of different Land Cover Types (LCTs) such as snow, water, vegetation, bare land, impervious, and shadow surfaces. This index can increase the separability between NBSI-MS values corresponding to snow from other LCTs and accurately delineate the snow/ice cover in non-binary maps. To test the robustness of the NBSI-MS, Greenland and France-Italy regions were examined where snow interacts with highly diversified geographical ecosystem. Data recorded by Landsat 5 TM, Landsat 8 OLI, and Sentinel-2A MSI satellites have been used. The NBSI-MS performance was also compared against the well-known NDSI, NDSII-1, S3, and SWI methods and evaluated based on Ground Reference Test Pixels (GRTPs) over non-binarized results. The results show that the NBSI-MS achieves overall accuracy (OA) ranging from 0.99 to 1 with kappa coefficient values in the same range as OA. The precision assessment confirms the performance superiority of the proposed NBSI-MS method for removing water and shadow surfaces over the compared relevant indices.
description: 22 pages, 12 figures
"und plötzlich hat man die richtigen Augen": Bild und Bildlichkeit in der literarischen Moderne
Creators: name: Zwernemann, Jens
Publisher: name: KULT_online
Year: 2005

description: "Wenn ich mich erinnere, wie befremdet und unsicher man die ersten Sachen sah", schrieb Rainer Maria Rilke seiner Frau, nachdem er die epochemachende Cézanne-Retrospektive im Pariser Herbstsalon von 1907 gesehen hatte: "[...] lange nichts und plötzlich hat man die richtigen Augen." Rilke thematisierte damit nicht nur die in Cézannes Werk so zentrale Frage der Wahrnehmung von Realität ebenso wie von Kunst, sondern bekundete auch sein großes Interesse an der Malerei, von der er sich Lösungen für seine schriftstellerischen Probleme erhoffte. Dass Rilke nicht der einzige modernistische Autor war, für den die Frage nach den unterschiedlichen Formen und Funktionen von Bildern und Bildlichkeit in der Literatur zentrale Bedeutung erlangte, wird in den 12 Beiträgen des vorliegenden Bandes demonstriert. Deren Autorinnen und Autoren analysieren dabei anhand von Werken Rilkes aber auch Hugo von Hofmannsthals, Richard Beer-Hofmanns, Max Dauthendeys und anderer die Auswirkungen der ikonischen Wende auf die Literatur um 1900.
description: KULT_online, Nr. 06 (2005): KULT_online 06 (2005)
Bulk asymptotics of skew-orthogonal polynomials for quartic double well potential and universality in the matrix model
Creators: name: Ghosh, Saugata
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We derive bulk asymptotics of skew-orthogonal polynomials (sop) $π^{\bt}_{m}$, $β=1$, 4, defined w.r.t. the weight $\exp(-2NV(x))$, $V (x)=gx^4/4+tx^2/2$, $g>0$ and $t<0$. We assume that as $m,N \to\infty$ there exists an $ε> 0$, such that $ε\leq (m/N)\leq λ_{\rm cr}-ε$, where $λ_{\rm cr}$ is the critical value which separates sop with two cuts from those with one cut. Simultaneously we derive asymptotics for the recursive coefficients of skew-orthogonal polynomials. The proof is based on obtaining a finite term recursion relation between sop and orthogonal polynomials (op) and using asymptotic results of op derived in \cite{bleher}. Finally, we apply these asymptotic results of sop and their recursion coefficients in the generalized Christoffel-Darboux formula (GCD) \cite{ghosh3} to obtain level densities and sine-kernels in the bulk of the spectrum for orthogonal and symplectic ensembles of random matrices.
description: 6 pages
Zwischen Gemeinschaft und Gesellschaft. Über den kulturellen Partikularismus
Creators: name: Sepp, Arvi
Publisher: name: KULT_online
Year: 2005

description: Das Werk des französischen Soziologen Michel Wieviorka versteht sich als systematisierende Bestandsaufnahme der neueren Multikulturalismusforschung bzw. als deren kritische Weiterführung. In dem hauptsächlich soziologisch geprägten Band wird untersucht, wie sich kulturelle Partikularismen mit ihrem differenzierenden religiösen, ethnischen, regionalen oder sexuellen Selbstverständnis in der westlichen Moderne definieren, (re)konstruieren und reproduzieren. In diesem Kontext rückt Wieviorka Konzepte wie "Identität", "Subjektivität" und "Differenz" in ein neues Licht.
description: KULT_online, Nr. 06 (2005): KULT_online 06 (2005)
Learning Text-Image Joint Embedding for Efficient Cross-Modal Retrieval with Deep Feature Engineering
Creators: name: Xie, Zhongwei
name: Liu, Ling
name: Wu, Yanzhao
name: Zhong, Luo
name: Li, Lin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: This paper introduces a two-phase deep feature engineering framework for efficient learning of semantics enhanced joint embedding, which clearly separates the deep feature engineering in data preprocessing from training the text-image joint embedding model. We use the Recipe1M dataset for the technical description and empirical validation. In preprocessing, we perform deep feature engineering by combining deep feature engineering with semantic context features derived from raw text-image input data. We leverage LSTM to identify key terms, deep NLP models from the BERT family, TextRank, or TF-IDF to produce ranking scores for key terms before generating the vector representation for each key term by using word2vec. We leverage wideResNet50 and word2vec to extract and encode the image category semantics of food images to help semantic alignment of the learned recipe and image embeddings in the joint latent space. In joint embedding learning, we perform deep feature engineering by optimizing the batch-hard triplet loss function with soft-margin and double negative sampling, taking into account also the category-based alignment loss and discriminator-based alignment loss. Extensive experiments demonstrate that our SEJE approach with deep feature engineering significantly outperforms the state-of-the-art approaches.
description: accepted by ACM Transactions on Information Systems(TOIS). arXiv admin note: text overlap with arXiv:2108.00705, arXiv:2108.03788
Combination quantum oscillations in canonical single-band Fermi liquids
Creators: name: Alexandrov, A. S.
name: Kabanov, V. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Chemical potential oscillations mix individual-band frequencies of the de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) magneto-oscillations in canonical low-dimensional multi-band Fermi liquids. We predict a similar mixing in canonical single-band Fermi liquids, which Fermi-surfaces have two or more extremal cross-sections. Combination harmonics are analysed using a single-band almost two-dimensional energy spectrum. We outline some experimental conditions allowing for resolution of combination harmonics.
Theatralität zwischen Avantgarde und Medienzeitalter
Creators: name: Mayer, Ewa
Publisher: name: KULT_online
Year: 2005

description: Ziel des Tagungsbandes ist die Überprüfung der im Titel gestellten Frage, ob (und inwiefern) Theater als Paradigma der Moderne gelten soll/kann. In neun Kapiteln, die thematisch auf der Einteilung der Tagung in Sektionen basieren, spüren Theater-, Tanz-, Film- und Fernsehwissenschaftler der paradigmatischen Funktion des Theaters nach. Die Aufsätze zeigen auf, wie dringend der Begriff der Theatralität, unabhängig aus welcher Forschungsperspektive betrachtet, heute neu zu verhandeln ist.
description: KULT_online, Nr. 07 (2005): KULT_online 07 (2005)
Das Bildnis in der Funktion des Quasi-Mitspielers in der europäischen Bühnengeschichte
Creators: name: Rothermel, Agata
Publisher: name: KULT_online
Year: 2005

description: Karin Bohnerts Studie liegt die Annahme zugrunde, dass Menschenbildnisse in dramatischen Texten mehr sind als bloße Gegenstände. Vielmehr entstehen zwischen dem Porträt und der porträtierten Figur spezifische Wechselbeziehungen, in denen die Bilder als Stellvertreter für ihr jeweiliges menschliches "Original" fungieren. In hermeneutischen Dramenanalysen zeigt Bohnert, wie das Bildnis zum Agierenden wird, und stellt dabei die Variabilität der Funktionen von Porträts in Bühnenstücken heraus.
description: KULT_online, Nr. 07 (2005): KULT_online 07 (2005)
Structure-Dependent Fluorescence Efficiencies of Individual Single-Walled Carbon Nanotubes
Creators: name: Tsyboulski, Dmitri A.
name: Rocha, John-David R.
name: Bachilo, Sergei M.
name: Cognet, Laurent
name: Weisman, R. Bruce
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Single-nanotube photometry was used to measure the product of absorption cross-section and fluorescence quantum yield for 12 (n,m) structural species of semiconducting SWNTs in aqueous SDBS suspension. These products ranged from 1.7 to 4.5 x 10(-19) cm2/C atom, generally increasing with optical band gap as described by the energy gap law. The findings suggest fluorescent quantum yields of ~8% for the brightest, (10,2) species and introduce the empirical calibration factors needed to deduce quantitative (n,m) distributions from bulk fluorimetric intensities.
Charge Imbalance and Bilayer 2D Electron Systems at $ν_T = 1$
Creators: name: Champagne, A. R.
name: Finck, A. D. K.
name: Eisenstein, J. P.
name: Pfeiffer, L. N.
name: West, K. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We use interlayer tunneling to study bilayer 2D electron systems at $ν_T = 1$ over a wide range of charge density imbalance, $Δν=ν_1-ν_2$, between the two layers. We find that the strongly enhanced tunneling associated with the coherent excitonic $ν_T = 1$ phase at small layer separation can survive at least up to an imbalance of $Δν$ = 0.5, i.e $(ν_1, ν_2)$ = (3/4, 1/4). Phase transitions between the excitonic $ν_T = 1$ state and bilayer states which lack significant interlayer correlations can be induced in three different ways: by increasing the effective interlayer spacing $d/\ell$, the temperature $T$, or the charge imbalance, $Δν$. We observe that close to the phase boundary the coherent $ν_T = 1$ phase can be absent at $Δν$ = 0, present at intermediate $Δν$, but then absent again at large $Δν$, thus indicating an intricate phase competition between it and incoherent quasi-independent layer states. At zero imbalance, the critical $d/\ell$ shifts linearly with temperature, while at $Δν$ = 1/3 the critical $d/\ell$ is only weakly dependent on $T$. At $Δν$ = 1/3 we report the first observation of a direct phase transition between the coherent excitonic $ν_T = 1$ bilayer integer quantum Hall phase and the pair of single layer fractional quantized Hall states at $ν_1$ = 2/3 and $ν_2=1/3$.
description: 13 pages, 8 postscript figures. Final published version
Dijkgraaf-Witten invariants of surfaces and projective representations of groups
Creators: name: Turaev, Vladimir
Publisher: name: arXiv
Year: 2007
Subjects: subject: Geometric Topology (math.GT)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 57R56, 81T45, 20C25

description: We compute the Dijkgraaf-Witten invariants of surfaces in terms of projective representations of groups. As an application we prove that the complex Dijkgraaf-Witten invariants of surfaces of positive genus are positive integers.
description: second version: a mistake corrected in the non-orientable case and a few improvements added
New Constraint of the Hubble Constant by Proper Motions of Radio Components Observed in AGN Twin-jets
Creators: name: Lu, Wei-Jian
name: Qin, Yi-Ping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: As the advent of precision cosmology, the Hubble constant ($H_0$) inferred from the Lambda Cold Dark Matter fit to the Cosmic Microwave Background data is increasingly in tension with the measurements from the local distance ladder. To approach its real value, we need more independent methods to measure, or to make constraint of, the Hubble constant. In this paper, we apply a plain method, which is merely based on the Friedman-Lemaître-Robertson-Walker cosmology together with geometrical relations, to constrain the Hubble constant by proper motions of radio components observed in AGN twin-jets. Under the assumption that the ultimate ejection strengths in both sides of the twin-jet concerned are intrinsically the same, we obtain a lower limit of the $H_{\rm 0,min}=51.5\pm2.3\,\rm km\,s^{-1}\,Mpc^{-1}$ from the measured maximum proper motions of the radio components observed in the twin-jet of NGC 1052.
description: 6 pages, 2 figures, accepted for publication on RAA
Notes on the Comedia di Danae by Baldassarre Taccone
Creators: name: Vescovo, Piermario
Publisher: name: La Rivista di Engramma
Year: 2020
Subjects: Danae
Baldassarre Taccone
Leonardo
mythological fable

description: The article concerns the Comedia di Danae by Baldassarre Taccone, a favola mitologica represented in Milan, in 1496 in its dramatic articulation and in relation to the myth relived in the courtly dimension. It makes particular reference to the modification of the conclusion, here with a transfiguration into a star of the protagonist, chaste girl and sacrificial victim.
Simulating radiation and kinetic processes in relativistic plasmas
Creators: name: Belmont, R.
name: Malzac, J.
name: Marcowith, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Modelling the emission properties of compact high energy sources such as X-ray binaries, AGN or gamma-ray bursts represents a complex problem. Contributions of numerous processes participate non linearly to produce the observed spectra: particle-particle, particle-photon and particle-wave interactions. In the past decades, numerical simulations have been widely used to address the key properties of the high energy plasmas present in these sources. This article presents a code that has been designed to investigate these questions. It includes most of the relevant processes needed to simulate the emission of high energy sources. This code solves the time-dependent kinetic equations for homogeneous, isotropic distributions of photons, electrons and positrons. No assumption is made on the shape of these distributions. Have been included so far: syn- chrotron self-absorbed radiation, Compton scattering, pair production/annihilation, e-e and e-p Coulomb collisions and some prescriptions for additional particle heating and acceleration. We also present comparisons with earlier works and some examples to illustrate the code computational capacities. Previous results are reproduced qualitatively but some differences are often found in the details of the particle As a first application of the code, we investigate acceleration by second order Fermi-like processes and we find that the energy threshold for acceleration has a crucial influence on the particle distribution and the emitted spectrum.
description: v3: minor language edition corrections. To be published in A&A
Electrical Neutrality and Symmetry Restoring Phase Transitions at High Density in a Two-Flavor Nambu-Jona-Lasinio Model
Creators: name: Wang, Xiao-Ming
name: Zhou, Bang-Rong
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A general research on chiral symmetry restoring phase transitions at zero temperature and finite chemical potentials under electrical neutrality condition has been conducted in a Nambu-Jona-Lasinio model to describe two-flavor normal quark matter. Depending on that $m_0/Λ$, the ratio of dynamical quark mass in vacuum and the 3D momentum cutoff in the loop integrals, is less or greater than 0.413, the phase transition will be second or first order. A complete phase diagram of $u$ quark chemical potential versus $m_0$ is given. With the electrical neutrality constraint, the region where second order phase transition happens will be wider than the one without electrical neutrality limitation. The results also show that, for the value of $m_0/Λ$ from QCD phenomenology, the phase transition must be first order.
description: 9 pages, 1 figure
A Critical Framework for Building Health Humanities Portraits
Creators: name: Sufian, Sandra
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: subject: 130205 Humanities and Social Sciences Curriculum and Pedagogy (excl. Economics, Business and Management)
subject: FOS: Educational sciences

description: This Health Humanities Portrait (HHP) Framework document outlines the main features for creating an HHP and where the emphasis lies.
Please also see the Teaching Guide Framework document for the sections to include when creating a teaching guide for the portrait.
The host galaxy of GRB031203: a new spectroscopic study
Creators: name: Margutti, R.
name: Chincarini, G.
name: Covino, S.
name: Tagliaferri, G.
name: Campana, S.
name: Della Valle, M.
name: Filippenko, A. V.
name: Fiore, F.
name: Foley, R.
name: Fugazza, D.
name: Giommi, P.
name: Malesani, D.
name: Moretti, A.
name: Stella, L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The host galaxy of the long-duration gamma-ray burst (GRB) 031203 (HG031203) offers a precious opportunity to study in detail the environment of a nearby GRB. The aim is to better characterize this galaxy and analyse the possible evolution with time of the spectroscopic quantities we derive. We analyse HG031203 using a set of optical spectra acquired with the ESO-VLT and Keck telescope. We compare the metallicity, luminosity and star formation properties of this galaxy and of the other supernova-long gamma-ray burst hosts in the local universe (z<0.2) against the KPNO International Spectroscopic Survey. HG031203 is a metal poor, actively star forming galaxy (star formation rate of 12.9+/-2.2 {M_{sun} yr^-1) at z=0.1054. From the emission-line analysis we derive an intrinsic reddening E_{HG}(B-V)\approx 0.4. This parameter doesn't show a compelling evidence of evolution at a month time-scale. We find an interstellar medium temperature of 12500 K and an electronic density of N_{e}=160 cm^-3. After investigating for possible Wolf-Rayet emission features in our spectra, we consider dubious the classification of HG031203 as a Wolf-Rayet galaxy. Long gamma-ray burst (LGRB) and supernova hosts in the local universe (z<0.2) show, on average, specific star formation rates higher than ordinary star forming galaxy at the same redshift. On the other hand, we find that half of the hosts follows the metallicity-luminosity relation found for star-burst galaxies; HG031203 is a clear outlier, with its really low metallicity (12+\log{O/H}=8.12+/-0.04).
description: 12 pages, 10 figures. Accepted by A&A
Holographic spectral functions and diffusion constants for fundamental matter
Creators: name: Myers, Robert C.
name: Starinets, Andrei O.
name: Thomson, Rowan M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The holographic dual of large-Nc super-Yang-Mills coupled to a small number of flavours of fundamental matter, Nf << Nc, is described by Nf probe D7-branes in the gravitational background of Nc black D3-branes. This system undergoes a first order phase transition characterised by the `melting' of the mesons. We study the high temperature phase in which the D7-branes extend through the black hole horizon. In this phase, we compute the spectral function for vector, scalar and pseudoscalar modes on the D7-brane probe. We also compute the diffusion constant for the flavour currents.
description: LaTex, 66 pages, 18 figures, final version
Two analytic relations connecting the hot gas astrophysics with the cold dark matter model for galaxy clusters
Creators: name: Chan, Man Ho
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Galaxy clusters are good targets for examining our understanding of cosmology. Apart from numerical simulations and gravitational lensing, X-ray observation is the most common and conventional way to analyze the gravitational structures of galaxy clusters. Therefore, it is valuable to have simple analytical relations that can connect the observed distribution of the hot, X-ray emitting gas to the structure of the dark matter in the clusters as derived from simulations. In this article, we apply a simple framework that can analytically connect the hot gas empirical parameters with the standard parameters in the cosmological cold dark matter model. We have theoretically derived two important analytic relations, $r_s \approx \sqrt{3}r_c$ and $ρ_s \approx 9βkT/8 πGm_gr_c^2$, which can easily relate the dark matter properties in galaxy clusters with the hot gas properties. This can give a consistent picture describing gravitational astrophysics for galaxy clusters by the hot gas and cold dark matter models.
description: Accepted in ApJ
No de Sitter invariant vacuum in massive gravity theory with ghost
Creators: name: Izumi, Keisuke
name: Tanaka, Takahiro
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this letter we point out that the massive gravity theory with a graviton ghost mode in de Sitter background cannot possess a de Sitter invariant vacuum state. In order to avoid a negative norm state, we must associate the creation operator of the ghost mode with a negative-energy mode function instead of a positive-energy one as the mode function. Namely, we have to adopt a different procedure of quantization for a ghost. When a theory has a symmetry mixing a ghost mode with ordinary non-ghost modes, the choice of a ghost mode is not unique. However, quantization of a ghost is impossible without specifying a choice of ghost mode, which breaks the symmetry. For this reason, the vacuum state cannot respect the symmetry. In the massive gravity theory with a graviton ghost mode in de Sitter background, the ghost is the helicity-0 mode of the graviton. This ghost mode is mixed with the other helicity graviton modes under the action of de Sitter symmetry. Therefore, there is no de Sitter invariant vacuum in such models. This leads to an interesting possibility that non-covariant cutoff of the low energy effective theory may naturally arise. As a result, the instability due to the pair production of a ghost and normal non-ghost particles gets much milder and that the model may escape from being rejected.
description: 5 pages
Spacetime Foam and Dark Energy
Creators: name: Ng, Y. Jack
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Due to quantum fluctuations, spacetime is foamy on small scales. The degree of foaminess is found to be consistent with the holographic principle. One way to detect spacetime foam is to look for halos in the images of distant quasars. Applying the holographic foam model to cosmology we "predict" that the cosmic energy density takes on the critical value; and basing only on existing archived data on active galactic nuclei from the Hubble Space Telescope, we also "predict" the existence of dark energy which, we argue, is composed of an enormous number of inert "particles" of extremely long wavelength. We speculate that these "particles" obey infinite statistics.
description: 6 pages, LaTeX, talk given at the Fourth International Workshop on the Dark Side of the Universe in Cairo (June 1-5, 2008), to appear in the Proceedings
A Critical Framework for Creating a Health Humanities Portrait Teaching Guide
Creators: name: Sufian, Sandra
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: subject: 130205 Humanities and Social Sciences Curriculum and Pedagogy (excl. Economics, Business and Management)
subject: FOS: Educational sciences

description: This Framework for Creating a Health Humanities Portrait Teaching Guide provides a description and template for health humanities educators to use when writing their teaching guide.
The teaching guide should be written with other non-creator faculty in mind--it should help those who teach the HHP to capture the main rationale, points, and discussion questions the creator intended./
Origin of Perpendicular Magnetic Anisotropy in Yttrium Iron Garnet Thin Films Grown on Si (100)
Creators: name: Capku, Zurbiye
name: Deger, Caner
name: Aksu, Perihan
name: Yildiz, Fikret
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We report the magnetic properties of yttrium iron garnet (YIG) thin films grown by pulsed laser deposition technique. The films were deposited on Si (100) substrates in the range of 15-50 nm thickness. Magnetic characterizations were investigated by ferromagnetic resonance spectra. Perpendicular magnetic easy axis was achieved up to 50 nm thickness. We observed that the perpendicular anisotropy values decreased by increasing the film thickness. The origin of the perpendicular magnetic anisotropy (PMA) was attributed to the texture and the lattice distortion in the YIG thin films. We anticipate that perpendicularly magnetized YIG thin films on Si substrates pave the way for a cheaper and compatible fabrication process.
Documenting variable provenance with DDI and Colectica
Creators: name: Iverson, Jeremy
Publisher: name: Zenodo
Year: 2019
Subjects: DDI
metadata
NADDI2019

description: DDI supports documenting data with variable-level detail. Normally such information includes a variable’s name, label and data type, but DDI supports the inclusion of more details (e.g., the variable’s lineage). The data behind a variable may have originated from a survey, from administrative data or from some other dataset. The variable may have been copied directly from a source, or it may have been calculated using a formula or algorithm. For a researcher to properly understand and analyze the data, the lineage of each variable should be documented in as much detail as possible.

Variable-level provenance information can be recorded by data management staff manually. However, in some cases it is also possible to extract the transformations that were used to create a variable based on statistical source code. The C2Metadata project, sponsored by the U.S. National Science Foundation, is building tools to accomplish this and to record the transformations in structured ways that can be included with data documentation.

This presentation will show data documentation from real studies that are providing variable-level provenance information and will discuss the methods used to create and publish the documentation.
Stellar intensity interferometry of Vega in photon counting mode
Creators: name: Zampieri, Luca
name: Naletto, Giampiero
name: Burtovoi, Aleksandr
name: Fiori, Michele
name: Barbieri, Cesare
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Stellar Intensity Interferometry is a technique based on the measurement of the second order spatial correlation of the light emitted from a star. The physical information provided by these measurements is the angular size and structure of the emitting source. A worldwide effort is presently under way to implement stellar intensity interferometry on telescopes separated by long baselines and on future arrays of Cherenkov telescopes. We describe an experiment of this type, realized at the Asiago Observatory (Italy), in which we performed for the first time measurements of the correlation counting photon coincidences in post-processing by means of a single photon software correlator and exploiting entirely the quantum properties of the light emitted from a star. We successfully detected the temporal correlation of Vega at zero baseline and performed a measurement of the correlation on a projected baseline of $\sim$2 km. The average discrete degree of coherence at zero baseline for Vega is $< g^{(2)} > \, = 1.0034 \pm 0.0008$, providing a detection with a signal-to-noise ratio $S/N \gtrsim 4$. No correlation is detected over the km baseline. The measurements are consistent with the expected degree of spatial coherence for a source with the 3.3 mas angular diameter of Vega. The experience gained with the Asiago experiment will serve for future implementations of stellar intensity interferometry on long-baseline arrays of Cherenkov telescopes.
description: 10 pages, 6 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
A Five-Planet Resonant Chain: Reevaluation of the Kepler-80 System
Creators: name: MacDonald, Mariah G.
name: Shakespeare, Cody J.
name: Ragozzine, Darin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Since the launch of the Kepler space telescope in 2009 and the subsequent K2 mission, hundreds of multi-planet systems have been discovered. The study of such systems, both as individual systems and as a population, leads to a better understanding of planetary formation and evolution. Kepler-80, a K-dwarf hosting six super-Earths, was the first system known to have four planets in a chain of resonances, a repeated geometric configuration. Transiting planets in resonant chains can enable us to estimate not only the planets' orbits and sizes but also their masses. Since the original resonance analysis and TTV fitting of Kepler-80, a new planet has been discovered whose signal likely altered the measured masses of the other planets. Here, we determine masses and orbits for all six planets hosted by Kepler-80 by direct forward photodynamical modeling of the lightcurve of this system. We then explore the resonant behaviour of the system. We find that the four middle planets are in a resonant chain, but that the outermost planet only dynamically interacts in $\sim14$\% of our solutions. We also find that the system and its dynamic behaviour are consistent with \emph{in situ} formation and compare our results to two other resonant chain systems, Kepler-60 and TRAPPIST-1.
description: 11 pages, 7 figures, accepted for publication in AJ
Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum
Creators: name: Branch, David
name: Troxel, M. A.
name: Jeffery, David J.
name: Hatano, Kazuhito
name: Musco, Miriam
name: Parrent, Jerod
name: Baron, E.
name: Dang, Leann Chau
name: Casebeer, D.
name: Hall, Nicholas
name: Ketchum, Wesley
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A comparative study of spectra of 21 Type Ia supernovae (SNe Ia) obtained about one week before maximum light, and 8 spectra obtained 11 or more days before maximum, is presented. To a large extent the premaximum spectra exhibit the defining characteristics of the four groups defined in Paper II (core-normal, broad-line, cool, and shallow-silicon). Comparisons with SYNOW synthetic spectra show that all strong features and most weak ones can be accounted for in a plausible way. The issues of detached high-velocity features, the possible ubiquity of carbon clumps, the maximum detectable ejecta velocities, and the possibility of blueshifted emission-line peaks are discussed.
description: Accepted by PASP. 38 pages
Nonlinear Least Squares for Large-Scale Machine Learning using Stochastic Jacobian Estimates
Creators: name: Brust, Johannes J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: G.1.6; G.4; I.2.6
subject: 68T07, 68T20, 65K05

description: For large nonlinear least squares loss functions in machine learning we exploit the property that the number of model parameters typically exceeds the data in one batch. This implies a low-rank structure in the Hessian of the loss, which enables effective means to compute search directions. Using this property, we develop two algorithms that estimate Jacobian matrices and perform well when compared to state-of-the-art methods.
Twisted cohomologies of wrap groups over quaternions and octonions
Creators: name: Ludkovsky, S. V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Topology (math.AT)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 55N30; 55T25; 17A70; 22E20; 57S20

description: This article is devoted to the investigation of wrap groups of connected fiber bundles over the fields of real $\bf R$, complex $\bf C$ numbers, the quaternion skew field $\bf H$ and the octonion algebra $\bf O$. Cohomologies of wrap groups and their structure are investigated. Sheaves of wrap groups are constructed and studied. Moreover, twisted cohomologies and sheaves over quaternions and octonions are investigated as well.
description: 54 pages
Trans-Planckian Physics from a Nonlinear Dispersion Relation
Creators: name: Joras, S. E.
name: Marozzi, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a particular nonlinear dispersion relation $ω_p(k_p)$ -- a series expansion in the physical wavenumber $k_p$ -- for modeling first-order corrections in the equation of motion of a test scalar field in a de Sitter spacetime from trans-Planckian physics in cosmology. Using both a numerical approach and a semianalytical one, we show that the WKB approximation previously adopted in the literature should be used with caution, since it holds only when the comoving wavenumber $k\gg aH$. We determine the amplitude and behavior of the corrections on the power spectrum for this test field. Furthermore, we consider also a more realistic model of inflation, the power-law model, using only a numerical approach to determine the corrections on the power spectrum.
description: 11 pages, 10 figures. Some changes made, comments and references added, a figure added, typos corrected, conclusions unchanged, version accepted for pubblication in Phys. Rev. D
The Origin of Radio Emission in Black Hole X-ray Binaries
Creators: name: Liu, Xiang
name: Chang, Ning
name: Wang, Xin
name: Yuan, Qi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We studied the relation of accretion-jet power and disk luminosity, especially the jet efficiencies and disk radiative efficiencies for different accretion disks as well as black hole (BH) spin, in order to explore the origin of radio emission in black hole X-ray binaries (BHXBs). We found that jet efficiency increases more rapidly (efficient) than the nearly constant disk radiative efficiency for thin disk component in high accretion regime, which could account for the steep track ($μ>1$) in the observed radio and X-ray luminosity relations ($L_{\rm R}\propto L_{\rm X}^μ$), but the thin disk component may not be able to explain the standard track ($μ\approx 0.6$) in the BHXBs. For hot accretion flows (HAF), the resulting jet efficiency changes along with the large range of accretions from quiescent state to nearly Eddington state, which could account for the standard track in the BHXBs. The BH spin-jet is discussed for the magnetic arrested disk (MAD) state; in this state, the spin-jet power might contribute to a linear correlation between jet power and mass accretion rate for a given source. More accurate observations are required to test the results.
description: 10 pages, 2 figures, accepted for publication in Galaxies
Anomalous Hall effect in a two-dimensional electron gas
Creators: name: Nunner, Tamara S.
name: Sinitsyn, N. A.
name: Borunda, Mario F.
name: Kovalev, A. A.
name: Abanov, Ar.
name: Timm, Carsten
name: Jungwirth, T.
name: Inoue, Jun-ichiro
name: MacDonald, A. H.
name: Sinova, Jairo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The anomalous Hall effect in a magnetic two-dimensional electron gas with Rashba spin-orbit coupling is studied within the Kubo-Streda formalism in the presence of pointlike potential impurities. We find that all contributions to the anomalous Hall conductivity vanish to leading order in disorder strength when both chiral subbands are occupied. In the situation that only the majority subband is occupied, all terms are finite in the weak scattering limit and the total anomalous Hall conductivity is dominated by skew scattering. We compare our results to previous treatments and resolve some of the discrepancies present in the literature.
description: 11 pages, 5 figures
Lane-formation vs. cluster-formation in two dimensional square-shoulder systems: A genetic algorithm approach
Creators: name: Fornleitner, Julia
name: Kahl, Gerhard
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Introducing genetic algorithms as a reliable and efficient tool to find ordered equilibrium structures, we predict minimum energy configurations of the square shoulder system for different values of corona width $λ$. Varying systematically the pressure for different values of $λ$ we obtain complete sequences of minimum energy configurations which provide a deeper understanding of the system's strategies to arrange particles in an energetically optimized fashion, leading to the competing self-assembly scenarios of cluster-formation vs. lane-formation.
description: 5 pages, 6 figures
Diffuse field cross-correlations: scattering theory and electromagnetic experiments
Creators: name: Davy, Matthieu
name: Besnier, Philippe
name: del Hougne, Philipp
name: de Rosny, Julien
name: Richalot, Elodie
name: Sarrazin, François
name: Savin, Dmitry V.
name: Mortessagne, Fabrice
name: Kuhl, Ulrich
name: Legrand, Olivier
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The passive estimation of impulse responses from ambient noise correlations arouses increasing interest in seismology, acoustics, optics and electromagnetism. Assuming the equipartition of the noise field, the cross-correlation function measured with non-invasive receiving probes converges towards the difference of the causal and anti-causal Green's functions. Here, we consider the case when the receiving field probes are antennas which are well coupled to a complex medium -- a scenario of practical relevance in electromagnetism. We propose a general approach based on the scattering matrix formalism to explore the convergence of the cross-correlation function. The analytically derived theoretical results for chaotic systems are confirmed in microwave measurements within a mode-stirred reverberation chamber. This study provides new fundamental insights into the Green's function retrieval technique and paves the way for a new technique to characterize electromagnetic antennas.