cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Massless scalar particle on AdS spacetime: Hamiltonian reduction and quantization
Creators: name: Dorn, Harald
name: Jorjadze, George
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the massless scalar particle dynamics on $AdS_{N+1} ~ (N>1)$ by the method of Hamiltonian reduction. Using the dynamical integrals of the conformal symmetry we construct the physical phase space of the system as a $SO(2,N+1)$ orbit in the space of symmetry generators. The symmetry generators themselves are represented in terms of $(N+1)$-dimensional oscillator variables. The physical phase space establishes a correspondence between the $AdS_{N+1}$ null-geodesics and the dynamics at the boundary of $AdS_{N+2}$. The quantum theory is described by a UIR of $SO(2,N+1)$ obtained at the unitarity bound. This representation contains a pair of UIR's of the isometry subgroup SO(2,N) with the Casimir number corresponding to the Weyl invariant mass value. The whole discussion includes the globally well-defined realization of the conformal group via the conformal embedding of $AdS_{N+1}$ in the ESU $\rr\times S^N$.
description: 14 pages, Latex
Poincaré Invariant Three-Body Scattering at Intermediate Energies
Creators: name: Lin, T.
name: Elster, Ch.
name: Polyzou, W. N.
name: Witala, H.
name: Gloeckle, W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The relativistic Faddeev equation for three-nucleon scattering is formulated in momentum space and directly solved in terms of momentum vectors without employing a partial wave decomposition. The equation is solved through Padé summation, and the numerical feasibility and stability of the solution is demonstrated. Relativistic invariance is achieved by constructing a dynamical unitary representation of the Poincaré group on the three-nucleon Hilbert space. Based on a Malfliet-Tjon type interaction, observables for elastic and break-up scattering are calculated for projectile energies in the intermediate energy range up to 2 GeV, and compared to their nonrelativistic counterparts. The convergence of the multiple scattering series is investigated as a function of the projectile energy in different scattering observables and configurations. Approximations to the two-body interaction embedded in the three-particle space are compared to the exact treatment.
description: 16 pages, 13 figures
Growth and Characterization of Metalorganic Vapor-Phase Epitaxy-Grown \b{eta}-(AlxGa1-x)2O3/\b{eta}-Ga2O3 Heterostructure Channels
Creators: name: Ranga, Praneeth
name: Bhattacharyya, Arkka
name: Chmielewski, Adrian
name: Roy, Saurav
name: Sun, Rujun
name: Scarpulla, Michael A.
name: Alem, Nasim
name: Krishnamoorthy, Sriram
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on the growth and characterization of metalorganic vapor-phase epitaxy-grown \b{eta}-(AlxGa1-x)2O3/\b{eta}-Ga2O3 modulation-doped heterostructures. Electron channel is realized in the heterostructure by utilizing a delta-doped \b{eta}-(AlxGa1-x)2O3 barrier. Electron channel characteristics are studied using transfer length method, capacitance-voltage and Hall measurements. Hall sheet charge density of 1.06 x 1013 cm-2 and mobility of 111 cm2/Vs is measured at room temperature. Fabricated transistor showed peak current of 22 mA/mm and on-off ratio of 8 x 106. Sheet resistance of 5.3 kΩ/Square is measured at room temperature, which includes contribution from a parallel channel in \b{eta}-(AlxGa1-x)2O3.
description: 22 pages, 4 figures
The Elliptic curves in gauge theory, string theory, and cohomology
Creators: name: Sati, Hisham
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Elliptic curves play a natural and important role in elliptic cohomology. In earlier work with I. Kriz, thes elliptic curves were interpreted physically in two ways: as corresponding to the intersection of M2 and M5 in the context of (the reduction of M-theory to) type IIA and as the elliptic fiber leading to F-theory for type IIB. In this paper we elaborate on the physical setting for various generalized cohomology theories, including elliptic cohomology, and we note that the above two seemingly unrelated descriptions can be unified using Sen's picture of the orientifold limit of F-theory compactification on K3, which unifies the Seiberg-Witten curve with the F-theory curve, and through which we naturally explain the constancy of the modulus that emerges from elliptic cohomology. This also clarifies the orbifolding performed in the previous work and justifies the appearance of the w_4 condition in the elliptic refinement of the mod 2 part of the partition function. We comment on the cohomology theory needed for the case when the modular parameter varies in the base of the elliptic fibration.
description: 23 pages, typos corrected, minor clarifications
Elicitation on person marking and Wh-extraction
Creators: name: Kajkwakhrattxi, Nokêrê
name: Beauchamp, Jérémie
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: Kajkwakhrattxi language

description: Includes typed field notes.

August 14: person marking and Wh-extraction
August 16: Wh-extraction
Active Mass Under Pressure
Creators: name: Ehlers, Juergen
name: Ozsvath, Istvan
name: Schucking, Engelbert
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: After a historical introduction to Poisson's equation for Newtonian gravity, its analog for static gravitational fields in Einstein's theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein's theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century ago in the Hamburg Relativity Seminar and is resolved here.
description: 28 pages, 4 figures
Explorations beyond dilaton chiral perturbation theory in the eight-flavor SU(3) gauge theory
Creators: name: Golterman, Maarten
name: Shamir, Yigal
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We continue our study of spectroscopy data for the SU(3) gauge theory with eight fundamental fermions, motivated by the effective field theory framework of dilaton chiral perturbation theory (dChPT). At leading order dChPT predicts a constant mass anomalous dimension $γ_m$, consistent with the assumed proximity of an infrared fixed point. For the relatively large fermion masses simulated by the LatKMI collaboration, the influence of the infrared fixed point diminishes, and our fits suggest that $γ_m$ starts running. Since a complete higher-order analysis is not feasible with presently available data, we adopt a more phenomenological approach. We propose a partial extension to higher orders, which incorporates the running of $γ_m$ into the tree-level lagrangian. We find that this extension successfully describes the full fermion-mass range of the LatKMI data, including the pion taste splittings which arise from using staggered fermions in the lattice simulations. We also investigate a more general class of dilaton potentials proposed in the literature, using both the LSD and LatKMI data sets, concluding that these data favor the form predicted by dChPT.
description: RevTeX, 35 pages. Published version; appendix about scale setting added
An adaptive subband-based joint source-channel coder for image transmission
Creators: name: Alavi, Amin
Publisher: name: University of British Columbia
Year: 2009

description: An adaptive subband image coding system is proposed that uses DPCM and PCM codecs for source encoding the individual subbands, and a family of variable rate channel codes for forward error correction. A low resolution family of trellis coded modulation codes and a high resolution family of punctured convolutional channel codes are implemented and investigated. Implementation of unequal error protection among the subbands, and within the subbands, is examined for the two separate versions of our system. Simulations are performed on the AWGN channel and comparisons are made with corresponding systems that use only a single channel code, or that use the same family of codes for an adaptive equal error protection scheme. Our proposed adaptive systems outperform any of the systems that use only a single channel code greatly, extending the useful SNR range by an amount that depends on the code family. As well, our systems outperform the corresponding adaptive equal error protection systems by as much as 2 dB PSNR. This is primarily due to the use of unequal error protection among the subbands, as surprisingly little additional gain is achieved by applying unequal error protection within the subbands. We use and improve a known modelling technique which enables the system to configure itself optimally for the transmission of an arbitrary image, by only measuring the mean of lowest frequency subband and variance of each of its subbands. Because our systems require an estimate of the channel SNR, we have investigated the sensitivity to poor channel SNR estimation, and have found negligible performance loss for channel mismatches up to 1.5 dB.
Leptonic widths of heavy quarkonia: S-Wave QCD/NRQCD matching coefficients for the electromagnetic vector annihilation current at O(alpha_s v^2)
Creators: name: Hart, A.
name: von Hippel, G. M.
name: Horgan, R. R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We construct the S-wave part of the electromagnetic vector annihilation current to O(alpha_s v^2)$ on the lattice for heavy quarks whose dynamics are described by the NRQCD action, where v is the non-relativistic quark velocity. The lattice vector current for QQbar annihilation is expressed as a linear combination of lattice operators with quantum numbers L=0, J^P=1^-, and the coefficients are determined by matching this lattice current to the corresponding continuum current in QCD to O(v^2) to one-loop. The annihilation channel gives a complex amplitude and a proper choice for the contours of integration is needed; a simple Wick rotation is not possible. In this way, and with a careful choice of subtraction functions in the numerical integration, the Coulomb-exchange and infrared singularities appearing in the amplitudes are successfully treated. The matching coefficients are given as a function of the heavy quark mass Ma in lattice units. An automated vertex generation program written in Python is employed, allowing us to use a realistic NRQCD action and an improved gluon lattice action. A change in the definition of either action is easily accommodated in this procedure. The final result is applicable to the electromagnetic decays of heavy quarkonia, notably the Upsilon meson.
description: Corrections to section VA
Tensor network study of the $m=1/2$ magnetization plateau in the Shastry-Sutherland model at finite temperature
Creators: name: Czarnik, Piotr
name: Rams, Marek M.
name: Corboz, Philippe
name: Dziarmaga, Jacek
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The two-dimensional infinite projected entangled pair states tensor network is evolved in imaginary time with the full update (FU) algorithm to simulate the Shastry-Sutherland model in a magnetic field at finite temperature directly in the thermodynamic limit. We focus on the phase transition into the $m=1/2$ magnetization plateau, which was observed in experiments on SrCu$_2$(BO$_3$)$_2$. For the largest simulated bond dimension, the early evolution in the high-temperature regime is simulated with the simple update (SU) scheme and then, as the correlation length increases, continued with the FU scheme towards the critical regime. We apply a small symmetry-breaking bias field and then extrapolate towards zero bias using a simple scaling theory in the bias field. The combined SU + FU scheme provides an accurate estimate of the critical temperature, even though the results could not be fully converged in the bond dimension in the vicinity of the transition. The critical temperature estimate is improved with a generalized scaling theory that combines two divergent length scales: One due to the bias, and the other due to the finite bond dimension. The obtained results are consistent with the transition being in the universality class of the two-dimensional classical Ising model. The estimated critical temperature is $3.5(2)$ K, which is well above the temperature $2.1$ K used in the experiments.
description: 13 pages, 7 figures and 5 tables
Analysis of a quantum logic device based on dipole-dipole interactions of optically trapped Rydberg atoms
Creators: name: Saffman, M.
name: Walker, T. G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a detailed analysis and design of a neutral atom quantum logic device based on atoms in optical traps interacting via dipole-dipole coupling of Rydberg states. The dominant physical mechanisms leading to decoherence and loss of fidelity are enumerated. Our results support the feasibility of performing single and two-qubit gates at MHz rates with decoherence probability and fidelity errors at the level of $10^{-3}$ for each operation. Current limitations and possible approaches to further improvement of the device are discussed.
description: 23 pages, 14 figures, typos corrected
Gravitational effective action at mesoscopic scales from the quantum microstructure of spacetime
Creators: name: Padmanabhan, T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: At mesoscopic scales, the quantum corrected field equations of gravity should arise from extremizing, $Ω$, the number of microscopic configurations of pre-geometric variables consistent with a given geometry. This $Ω$, in turn, is the product over all events P of the density, $ρ(P)$, of microscopic configurations associated with each event P. One would have expected $ρ\propto\sqrt{g}$ so that $ρd^4x$ scales as the proper volume of a region. On the other hand, at leading order, we would expect the extremum principle to be based on the Hilbert action, suggesting $\lnρ\propto R$. I show how these two apparently contradictory requirements can be reconciled by using the functional dependence of $\sqrt{g}$ on curvature, in the Riemann normal coordinates (RNC), and coarse-graining over Planck scales. This leads to the density of microscopic configurations to be $ρ= Δ^{-1} = \sqrt{g}_{RNC}$ where $Δ$ is the coarse grained Van-Vleck determinant. The approach also provides: (a) systematic way of computing QG corrections to field equations and (b) a direct link between the effective action for gravity and the kinetic theory of the spacetime fluid.
description: ver 2: minor edits; no figures; 9 pages
Phenomenological analysis of transverse thermoelectric generation and cooling performance in magnetic/thermoelectric hybrid systems
Creators: name: Yamamoto, Kaoru
name: Iguchi, Ryo
name: Miura, Asuka
name: Zhou, Weinan
name: Sakuraba, Yuya
name: Miura, Yoshio
name: Uchida, Ken-ichi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We phenomenologically calculate the performance of the recently-observed Seebeck-driven transverse thermoelectric generation (STTG) for various systems in terms of the thermopower, power factor, and figure of merit to demonstrate the usefulness of STTG. The STTG system consists of a closed circuit comprising thermoelectric and magnetic materials which exhibit the Seebeck and anomalous Hall effects, respectively. When a temperature gradient is applied to the hybrid system, the Seebeck effect in the thermoelectric material layer generates a longitudinal charge current in the closed circuit and the charge current subsequently drives the anomalous Hall effect in the magnetic material layer. The anomalous Hall voltage driven by the Seebeck effect has a similar symmetry to the transverse thermoelectric conversion based on the anomalous Nernst effect. We find that the thermoelectric properties of STTG can be much better than those of the anomalous Nernst effect by increasing the Seebeck coefficient and anomalous Hall angle of the thermoelectric and magnetic materials, respectively, as well as by optimizing their dimensions. We also formulate the electronic cooling performance in the STTG system, confirming the reciprocal relation for the hybrid transverse thermoelectric conversion.
description: 7 pages, 4 figures
Idealized Slab Plasma approach for the study of Warm Dense Matter
Creators: name: Ng, A.
name: Ao, T.
name: Perrot, F.
name: Dharma-wardana, M. W. C.
name: Foord, M. E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Astrophysics (astro-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Recently, warm dense matter (WDM) has emerged as an interdisciplinary field that draws increasing interest in plasma physics, condensed matter physics, high pressure science, astrophysics, inertial confinement fusion, as well as materials science under extreme conditions. To allow the study of well-defined WDM states, we have introduced the concept of idealized-slab plasmas that can be realized in the laboratory via (i) the isochoric heating of a solid and (ii) the propagation of a shock wave in a solid. The application of this concept provides new means for probing the dynamic conductivity, equation of state, ionization and opacity. These approaches are presented here using results derived from first-principles (density-functional type) theory, Thomas-Fermi type theory, and numerical simulations.
description: 37 pages, 21 figures, available, pdf file only. To appear in: Laser and Particle beams. To appear more or less in this form in Laser and Particle beams
Continuous measurements in probability representation of quantum mechanics
Creators: name: Przhiyalkovskiy, Yan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The continuous quantum measurement within the probability representation of quantum mechanics is discussed. The partial classical propagator of the symplectic tomogram associated to a particular measurement outcome is introduced, for which the representation of a continuous measurement through the restricted path integral is applied. The classical propagator for the system undergoing a non-selective measurement is derived by summing these partial propagators over the entire outcome set. The elaborated approach is illustrated by considering non-selective position measurement of a quantum oscillator and a particle.
Linear and Neural Network Estimates of Magnetic Filling Factors on Sun-Like Stars
Creators: name: Milbourne, T.
name: Phillips, D.
name: Langellier, N.
name: Saar, S.
name: Walsworth, R.
Publisher: name: Zenodo
Year: 2021
Subjects: The Sun and the Heliosphere

description: State of the art radial velocity (RV) searches for low-mass exoplanets are limited by the effects of stellar magnetic activity. Previously, we have shown that different types of active regions - spots, plage, and network - have different impacts on the apparent stellar RV. Differentiating the relative coverage of these active regions is thus necessary in order to successfully disentangle the RV signatures of stars from potential planetary signals. However, traditional activity indicators, such as the calcium S-index and photometry, only indicate the overall coverage by magnetized regions: more information is necessary to differentiate the different types of active regions. In this work, we outline techniques to estimate magnetic filling factors from spots, plage, and networks features on stellar targets using only spectroscopic and photometric observations. We demonstrate linear and neural network implementations of our techniques using real solar observations taken by the solar telescope at HARPS-N, the HK Project at the Mt. Wilson Observatory, and the Total Irradiance Monitor onboard SORCE, and compare the results of each technique to filling factors derived from full-disk images from the Solar Dynamics Observatory. We conclude by assessing the possibilities of applying these techniques to non-solar targets.
Feature Fusion via Dual-resolution Compressive Measurement Matrix Analysis For Spectral Image Classification
Creators: name: Ramirez, Juan Marcos
name: Martinez-Torre, Jose Ignacio
name: Arguello, Henry
Publisher: name: arXiv
Year: 2020
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In the compressive spectral imaging (CSI) framework, different architectures have been proposed to recover high-resolution spectral images from compressive measurements. Since CSI architectures compactly capture the relevant information of the spectral image, various methods that extract classification features from compressive samples have been recently proposed. However, these techniques require a feature extraction procedure that reorders measurements using the information embedded in the coded aperture patterns. In this paper, a method that fuses features directly from dual-resolution compressive measurements is proposed for spectral image classification. More precisely, the fusion method is formulated as an inverse problem that estimates high-spatial-resolution and low-dimensional feature bands from compressive measurements. To this end, the decimation matrices that describe the compressive measurements as degraded versions of the fused features are mathematically modeled using the information embedded in the coded aperture patterns. Furthermore, we include both a sparsity-promoting and a total-variation (TV) regularization terms to the fusion problem in order to consider the correlations between neighbor pixels, and therefore, improve the accuracy of pixel-based classifiers. To solve the fusion problem, we describe an algorithm based on the accelerated variant of the alternating direction method of multipliers (accelerated-ADMM). Additionally, a classification approach that includes the developed fusion method and a multilayer neural network is introduced. Finally, the proposed approach is evaluated on three remote sensing spectral images and a set of compressive measurements captured in the laboratory. Extensive simulations show that the proposed classification approach outperforms other approaches under various performance metrics.
description: 24 pages, 12 figures and 3 tables
Lattice QCD study of static quark and antiquark correlations at finite $T$ via entanglement entropies
Creators: name: Takahashi, Toru T.
name: Kanada-En'yo, Yoshiko
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: With the aim of clarification of color correlations among quarks, we investigate the color correlation between a static quark and an antiquark (static $q\bar q$) below and above the phase transition temperature $T_c$ through the entanglement entropy(EE). By a quenched lattice QCD calculation on an anisotropic lattice adopting the standard Wilson gauge action in the Coulomb gauge, we compute a reduced density matrix $ρ$ defined in the color space, and the entanglement entropy $S_{\rm EE}$ constructed from $ρ$. The spatial volume is $L^3 = 24^3$ and the temporal extents are $N_T = 12,13,14,15,16,18,20$ and $24$, with a gauge coupling $β= 5.75$ and a renormalized anisotropy $ξ= 4.0$, which corresponds to temperatures between 180 and 370 MeV. From an analysis of $ρ$ and $S_{\rm EE}$, the color correlation between $q\bar q$ pairs is obtained as a function of the interquark distance $R$ and the temperature $T$. Below $T_c$, the $R$-dependence of the color correlation resembles that at $T=0$: the quark's color correlation gradually decreases as $R$ increases due to the color screening by in-between gluons. Above $T_c$, due to the deconfinement phase transition, the color correlation among quarks is found to quickly dissappear. Further, we investigate the color screening effect via the screening mass defined by $ρ$, and discuss the differences in the screening properties between the small and large R regions.
description: 8 pages, 4 figures
Elicitation on temporal expression, anaphor antecedents, and possession
Creators: name: Kajkwakhrattxi, Nokêrê
name: Beauchamp, Jérémie
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: Kajkwakhrattxi language

description: Includes typed field notes.

August 8: temporal expression, anaphor antecedents, possession
August 9: temporal expression
August 10: temporal expression, possession
August 11: possession
August 13: possession and antecedents
Religionsfreiheit als Anspruch und Herausforderung der Kirchen
Creators: name: Zeddies, Helmut
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 35 Nr. 4 (1986): Ökumenische Rundschau, Band 35, Heft 4
Electrochemical synthesis and crystal structure of the organic ion intercalated superconductor (TMA)0.5Fe2Se2 with Tc = 43 K
Creators: name: Rendenbach, Bettina
name: Hohl, Timotheus
name: Harm, Sascha
name: Hoch, Constantin
name: Johrendt, Dirk
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Intercalation of organic cations in superconducting iron selenide can significantly increase the critical temperature (Tc). We present an electrochemical method using beta-FeSe crystals (Tc ~ 8 K) floating on a mercury cathode to intercalate tetramethylammonium ions (TMA+) quantitatively to obtain bulk samples of (TMA)0.5Fe2Se2 with Tc = 43 K. The layered crystal structure is closely related to the ThCr2Si2-type with disordered TMA+ ions between the FeSe layers. Although the organic ions are not detectable by X-ray diffraction, packing requirements as well as first principle DFT calculations constrain the specified structure. Our synthetic route enables electrochemical intercalations of other organic cations with high yields to greatly optimize the superconducting properties, and to expand this class of high-Tc materials.
description: 21 pages, 10 Figures, including supplementary information
SiO Maser Sources toward Globular Clusters
Creators: name: Matsunaga, Noriyuki
name: Deguchi, Shuji
name: Ita, Yoshifusa
name: Tanabe, Toshihiko
name: Nakada, Yoshikazu
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the detection of SiO masers in Asymptotic Giant Branch variables toward bulge/disk globular clusters. In five out of six cases, the radial velocities are compatible with the optically measured radial velocities of globular clusters in the assessed uncertainty. Two sources, toward Terzan~5 and Terzan~12, lie very close to the cluster centers. The objects toward Pal~6 and Terzan~12 have luminosities appropriate to the AGB tip in globular clusters, while those toward NGC 6171, Pal~10, and Terzan~5 are brighter than expected. It is suggested that the latter three may have evolved from merged binaries, offering a test for binary-evolution scenarios in globular clusters, if the membership is approved.
description: 6 pages 1 figure PASJ, 57 No. 1 (in press)
Modelling COVID-19 transmission in supermarkets using an agent-based model
Creators: name: Ying, Fabian
name: O'Clery, Neave
Publisher: name: arXiv
Year: 2020
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Computers and Society (cs.CY)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Since the outbreak of COVID-19 in early March 2020, UK supermarkets have implemented different policies to reduce the virus transmission in stores to protect both customers and staff, such as restricting the maximum number of customers in a store, changes to the store layout, or enforcing a mandatory face covering policy. To quantitatively assess these mitigation methods, we formulate an agent-based model of customer movement in a supermarket (which we represent by a network) with a simple virus transmission model based on the amount of time a customer spends in close proximity to infectious customers. We apply our model to synthetic store and shopping data to show how one can use our model to estimate the number of infections due to human-to-human contact in stores and how to model different store interventions. The source code is openly available at https://github.com/fabianying/covid19-supermarket-abm. We encourage retailers to use the model to find the most effective store policies that reduce virus transmission in stores and thereby protect both customers and staff.
Optical phonon contribution to the thermal conductivity of a quantum paraelectric
Creators: name: Bhalla, Pankaj
name: Das, Nabyendu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by recent experimental findings, we study the contribution of a quantum critical optical phonon branch to the thermal conductivity of a paraelectric system. We consider the proximity of the optical phonon branch to transverse acoustic phonon branch and calculate its contribution to the thermal conductivity within the Kubo formalism. We find a low temperature power law dependence of the thermal conductivity as $T^α$, with $1 < α< 2$, (lower than $T^3$ behavior) due to optical phonons near the quantum critical point. This result is in accord with the experimental findings and indicates the importance of quantum fluctuations in the thermal conduction in these materials.
description: 9 pages, 8 figures
Single-Electron Transistor in Strained Si/SiGe Heterostructures
Creators: name: Berer, Thomas
name: Pachinger, Dietmar
name: Pillwein, Georg
name: Muehlberger, Michael
name: Lichtenberger, Herbert
name: Brunthaler, Gerhard
name: Schaeffler, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A split gate technique is used to form a lateral quantum dot in a two-dimensional electron gas of a modulation-doped silicon/silicon-germanium heterostructure. e-beam lithography was employed to produce split gates. By applying negative voltages to these gates the underlying electron gas is depleted and a lateral quantum dot is formed, the size of which can be adjusted by the gate voltage. We observe single-electron operation with Coulomb blockade behavior below 1K. Gate leakage currents are well controlled, indicating that the recently encountered problems with Schottky gates for this type of application are not an inherent limitation of modulation-doped Si/SiGe heterostructures, as had been speculated.
description: 3 pages
The application of discrete wavelet transforms to SAR image processing
Creators: name: Zeng, Zhaohui
Publisher: name: University of British Columbia
Year: 2009

description: Synthetic aperture radar (SAR) is a very efficient instrument for obtaining a. better understanding of the earth's environment. SAR, data represents an important source of information for a large variety of scientists around the world. However, the acquiring mechanism of SAR is quite different from other sensors, such as optical sensors. It brings some unique properties of SAR image data which decides that conventional image processing technique may fail to obtain satisfactory result or have to be modified to adapt the application of SAR image data. The objective of this thesis work is to investigate the potential of discrete wavelet transforms (DWT) for SAR image processing. The emphasis is placed on speckle noise reduction and SAR image compression, which are the two of the most popular application fields of DWT to image processing in the current literature. Two new algorithms for speckle reduction have been developed: a Bayesian method based on the statistical model and wavelet extrema based on the local property of wavelet coefficients, and have been applied to both airborne and spaceborne SAR images. The comparison of their results to some existing well known methods show their advantages on both the visual and numerical sides. In addition, simultaneous speckle reduction and data compression can significantly improve the compressibility of SAR images. The modified SPIHT aJgorithm has been applied to SAR image coding. The effectiveness of this strategy has been proven from the comparison to the method without speckle reduction and classic efficient wavelet compression algorithms.
Analytical Calculation of the Orbital Spectrum of the Guiding Center Motion in Axisymmetric Magnetic Fields
Creators: name: Antonenas, Yannis
name: Anastassiou, Giorgos
name: Kominis, Yannis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: Charged particle motion in axisymmetric toroidal magnetic fields is analyzed within the context of the canonical Hamiltonian Guiding Center theory. A canonical transformation to variables measuring the drift orbit deviation from a magnetic field line is introduced and an analytical transformation to Action-Angle variables is obtained, under a zero drift width approximation. The latter is used to provide compact formulas for the orbital spectrum of the drift motion, namely the bounce/transit frequencies as well as the bounce/transit averaged toroidal precession and gyration frequencies. These formulas are shown to have a remarkable agreement with numerically calculated full drift width frequencies and significant differences with standard analytical formulas based on a pendulum-like Hamiltonian description. The analytical knowledge of the orbital spectrum is crucial for the formulation of particle resonance conditions with symmetry breaking perturbations and the study of the resulting particle, energy and momentum transport.
description: 21 pages, 6 figures
Semiclassical limit for almost fermionic anyons
Creators: name: Girardot, Théotime
name: Rougerie, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Analysis of PDEs (math.AP)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In two-dimensional space there are possibilities for quantum statistics continuously interpolating between the bosonic and the fermionic one. Quasi-particles obeying such statistics can be described as ordinary bosons and fermions with magnetic interactions. We study a limit situation where the statistics/magnetic interaction is seen as a "perturbation from the fermionic end". We vindicate a mean-field approximation, proving that the ground state of a gas of anyons is described to leading order by a semi-classical, Vlasov-like, energy functional. The ground state of the latter displays anyonic behavior in its momentum distribution. Our proof is based on coherent states, Husimi functions, the Diaconis-Freedman theorem and a quantitative version of a semi-classical Pauli pinciple.
A spectroscopic study of southern (candidate) gamma Doradus stars. I. Time series analysis
Creators: name: De Cat, P.
name: Eyer, L.
name: Cuypers, J.
name: Aerts, C.
name: Vandenbussche, B.
name: Uytterhoeven, K.
name: Reyniers, K.
name: Kolenberg, K.
name: Groenewegen, M.
name: Raskin, G.
name: Maas, T.
name: Jankov, S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results of a spectroscopic study of 37 southern (candidate) gamma Doradus stars based on echelle spectra. The observed spectra were cross-correlated with the standard template spectrum of an F0-type star for an easier detection of binary and intrinsic variations. We identified 15 objects as spectroscopic binaries, including 7 new ones, and another 3 objects are binary suspects. At least 12 objects show composite spectra. We could determine the orbital parameters for 9 binaries, of which 4 turn out to be ellipsoidal variables. For 6 binaries, we estimated the expected time-base of the orbital variations. Clear profile variations are observed for 17 objects, pointing towards stellar pulsation. For 8 of them, we have evidence that the main spectroscopic and photometric periods coincide. Our results, in combination with prior knowledge from the literature, lead to the classification of 10 objects as new bona-fide gamma Doradus stars, 1 object as new bona-fide delta Scuti star, and 8 objects as constant stars. Finally, we determined the projected rotational velocity with two independent methods. The resulting vsini values range from 3 to 135 km/s. For the bona-fide gamma Doradus stars, the majority has vsini below 60 km/s.
description: 13 pages (+ 10 pages online material), 10 (+16) figures. Accepted for publication by A&A
An O(N^2) Approximation for Hydrodynamic Interactions in Brownian Dynamics Simulations
Creators: name: Geyer, Tihamer
name: Winter, Uwe
Publisher: name: arXiv
Year: 2008
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: In the Ermak-McCammon algorithm for Brownian Dynamics, the hydrodynamic interactions (HI) between N spherical particles are described by a 3N x 3N diffusion tensor. This tensor has to be factorized at each timestep with a runtime of O(N^3), making the calculation of the correlated random displacements the bottleneck for many-particle simulations. Here we present a faster algorithm for this step, which is based on a truncated expansion of the hydrodynamic multi-particle correlations as two-body contributions. The comparison to the exact algorithm and to the Chebyshev approximation of Fixman verifies that for bead-spring polymers this approximation yields about 95% of the hydrodynamic correlations at an improved runtime scaling of O(N^2) and a reduced memory footprint. The approximation is independent of the actual form of the hydrodynamic tensor and can be applied to arbitrary particle configurations. This now allows to include HI into large many-particle Brownian dynamics simulations, where until now the runtime scaling of the correlated random motion was prohibitive.
description: 8 pages, 4 figures; extended version: better approximation + added comparison to Ermak and Fixman HI for bead-spring polymers; submitted to JCP
Boundedness and unboundedness results for some maximal operators on functions of bounded variation
Creators: name: Aldaz, J. M.
name: Lázaro, J. Pérez
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 42B25, 26A84

description: We characterize the space $BV(I)$ of functions of bounded variation on an arbitrary interval $I\subset \mathbb{R}$, in terms of a uniform boundedness condition satisfied by the local uncentered maximal operator $M_R$ from $BV(I)$ into the Sobolev space $W^{1,1}(I)$. By restriction, the corresponding characterization holds for $W^{1,1}(I)$. We also show that if $U$ is open in $\mathbb{R}^d, d >1$, then boundedness from $BV(U)$ into $W^{1,1}(U)$ fails for the local directional maximal operator $M_T^{v}$, the local strong maximal operator $M_T^S$, and the iterated local directional maximal operator $M_T^{d}\circ ...\circ M_T^{1}$. Nevertheless, if $U$ satisfies a cone condition, then $M_T^S:BV(U)\to L^1(U)$ boundedly, and the same happens with $M_T^{v}$, $M_T^{d} \circ ...\circ M_T^{1}$, and $M_R$.
description: 15 pages
Commercial Hog Farms: Financial and Structural Characteristics, 1987-91
Creators: name: McElroy, Robert
name: Dodson, Charles
name: McElroy, Robert
name: Dodson, Charles
Publisher: name: Unknown
Year: 1994
Subjects: subject: Financial Economics
subject: Livestock Production/Industries
subject: Production Economics
subject: Hog farms
subject: farm income
subject: farm finance
subject: structure
subject: Farm Costs and Returns Survey

description: Commercial hog farms in 1987-91 had an average inventory of 2,000 hogs and operated 400 acres, according to the USDA's Farm Costs and Returns Survey (FCRS). Average net farm income ranged from $23,410 per farm in 1988 to $48,162 in 1990. The average operation's equity position improved each year and 72 percent of all operations were profitable in 1991.
Survey2Survey: A deep learning generative model approach for cross-survey image mapping
Creators: name: Buncher, Brandon
name: Sharma, Awshesh Nath
name: Kind, Matias Carrasco
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Machine Learning (cs.LG)
subject: Image and Video Processing (eess.IV)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: During the last decade, there has been an explosive growth in survey data and deep learning techniques, both of which have enabled great advances for astronomy. The amount of data from various surveys from multiple epochs with a wide range of wavelengths, albeit with varying brightness and quality, is overwhelming, and leveraging information from overlapping observations from different surveys has limitless potential in understanding galaxy formation and evolution. Synthetic galaxy image generation using physical models has been an important tool for survey data analysis, while deep learning generative models show great promise. In this paper, we present a novel approach for robustly expanding and improving survey data through cross survey feature translation. We trained two types of neural networks to map images from the Sloan Digital Sky Survey (SDSS) to corresponding images from the Dark Energy Survey (DES). This map was used to generate false DES representations of SDSS images, increasing the brightness and S/N while retaining important morphological information. We substantiate the robustness of our method by generating DES representations of SDSS images from outside the overlapping region, showing that the brightness and quality are improved even when the source images are of lower quality than the training images. Finally, we highlight several images in which the reconstruction process appears to have removed large artifacts from SDSS images. While only an initial application, our method shows promise as a method for robustly expanding and improving the quality of optical survey data and provides a potential avenue for cross-band reconstruction.
description: 24 pages, 19 figures. Accepted by MNRAS
Low-temperature nodal-quasiparticle transport in lightly doped YBa_{2}Cu_{3}O_{y} near the edge of the superconducting doping regime
Creators: name: Sun, X. F.
name: Segawa, Kouji
name: Ando, Yoichi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In-plane transport properties of nonsuperconducting YBa_{2}Cu_{3}O_{y} (y = 6.35) are measured using high-quality untwinned single crystals. We find that both the a- and b-axis resistivities show log(1/T) divergence down to 80 mK, and accordingly the thermal conductivity data indicate that the nodal quasiparticles are progressively localized with lowering temperature. Hence, both the charge and heat transport data do not support the existence of a "thermal metal" in nonsuperconducting YBa_{2}Cu_{3}O_{y}, as opposed to a recent report by Sutherland {\it et al.} [Phys. Rev. Lett. {\bf 94}, 147004 (2005)]. Besides, the present data demonstrate that the peculiar log(1/T) resistivity divergence of cuprate is {\it not} a property associated with high-magnetic fields.
description: 4 pages, 3 figures. Our previous main claim that the pseudogap state of cuprates is inherently insulating was found to be erroneous and has been retracted; the paper now focuses on the log(1/T) resistivity divergence and its implications
Identifying Crisis-Critical Intellectual Property Challenges during the Covid-19 Pandemic: A scenario analysis and conceptual extrapolation of innovation ecosystem dynamics using a visual mapping approach
Creators: name: Moerchel, Alexander
name: Tietze, Frank
name: Aristodemou, Leonidas
name: Vimalnath, Pratheeba
Publisher: name: Apollo - University of Cambridge Repository
Year: 2020
Subjects: econ.GN
q-fin.EC

description: The Covid-19 pandemic exposed firms, organisations and their respective supply chains which are directly involved in the manufacturing of products that are critical to alleviating the effects of the health crisis, collectively referred to as the Crisis-Critical Sector,to unprecedented challenges. Firms from other sectors, such as automotive, luxury and home appliances, have rushed into the Crisis-Critical Sector in order to support the effort to upscale incumbent manufacturing capacities, thereby introducing Intellectual Property (IP)related dynamics and challenges. We apply an innovation ecosystem perspective on the Crisis-Critical Sector and adopt a novel visual mapping approach to identify IP associated challenges and IP specific dynamic developments during and potentially beyond the crisis.In this paper, we add methodologically by devising and testing a visual approach to capturing IP related dynamics in evolving innovation ecosystems and contribute to literature on IP management in the open innovation context by proposing paraground IP as a novel IP type.Finally, we also deduce managerial implications for IP management practitioners at both incumbent firms and new entrants for navigating innovation ecosystems subject to crisis-induced dynamic shifts.