cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The observer-dependent shadow of the Kerr black hole
Creators: name: Chang, Zhe
name: Zhu, Qing-Hua
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Motivated by inclination of the Earth's orbit that is not located at galactic plane for observing the shadow of Sgr A*, we consider the black hole shadow for arbitrary inclinations and different velocities of observers. A surprising finding of the study is that rotation axis of a black hole might not be extracted from its shadow, since the ways of the shadow getting distorted depend not only on the spin of the black hole, but also velocities of observers. Namely, appearance of the shadow could be rotated by an angle in observers' celestial sphere due to the observer in motion. In order to further confirm this result, a formalism is presented for calculating the shadow in terms of the velocity perturbations. Besides, we also consider the Earth's orbit for the shadow of Sgr A* by making use of this formalism.
description: v2: 28 pages, 19 figures, 2 tables, minor revisions
Emergence of noncontextuality under quantum Darwinism
Creators: name: Baldijão, Roberto D.
name: Wagner, Rafael
name: Duarte, Cristhiano
name: Amaral, Bárbara
name: Cunha, Marcelo Terra
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum Darwinism proposes that the proliferation of redundant information plays a major role in the emergence of objectivity out of the quantum world. Is this kind of objectivity necessarily classical? We show that if one takes Spekkens' notion of noncontextuality as the notion of classicality and the approach of Brandão, Piani and Horodecki to quantum Darwinism, the answer to the above question is `yes', if the environment encodes sufficiently well the proliferated information. Moreover, we propose a threshold on this encoding, above which one can unambiguously say that classical objectivity has emerged under quantum Darwinism.
description: Essentially the accepted version. Enhanced clarity, but main results stand the same. Addition of two new subsections: 1- a cutoff for classical objectivity 2-state spectrum broadcasting case (+ the relative subsections to the appendix). For the final version, please look at PRX Quantum. 8 pages, 2 figures in the main text + 7 pages, 1 figure in the Appendix. Comments are welcome!
A-infinity structure on simplicial complexes
Creators: name: Dolotin, V.
name: Morozov, A.
name: Shakirov, Sh.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Geometric Topology (math.GT)
subject: Discrete Mathematics (cs.DM)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: A discrete (finite-difference) analogue of differential forms is considered, defined on simplicial complexes, including triangulations of continuous manifolds. Various operations are explicitly defined on these forms, including exterior derivative and exterior product. The latter one is non-associative. Instead, as anticipated, it is a part of non-trivial A-infinity structure, involving a chain of poly-linear operations, constrained by nilpotency relation: (d + \wedge + m + ...)^n = 0 with n=2.
description: final version. 29 pages
Optomechanical Synchronization across Multi-Octaves Frequency Spans
Creators: name: Rodrigues, Caique C.
name: Kersul, Cauê M.
name: Primo, André G.
name: Lipson, Michal
name: Alegre, Thiago P. M.
name: Wiederhecker, Gustavo S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Experimental exploration of synchronization in scalable oscillator micro systems has unfolded a deeper understanding of networks, collective phenomena, and signal processing. Cavity optomechanical devices have played an important role in this scenario, with the perspective of bridging optical and radio frequencies through nonlinear classical and quantum synchronization concepts. In its simplest form, synchronization occurs when an oscillator is entrained by a signal with frequency nearby the oscillator's tone, and becomes increasingly challenging as their frequency detuning increases. Here, we experimentally demonstrate entrainment of a silicon-nitride optomechanical oscillator driven up to the fourth harmonic of its 32 MHz fundamental frequency. Exploring this effect, we also experimentally demonstrate for the first time a purely optomechanical RF frequency divider, where we performed frequency division up to a 4:1 ratio, i.e., from 128 MHz to 32 MHz. Further developments could harness these effects towards frequency synthesizers, phase-sensitive amplification and nonlinear sensing.
Drift of charged defects in local fields as aging mechanism in ferroelectrics
Creators: name: Genenko, Yuri A.
name: Lupascu, Doru C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Point defect migration is considered as a mechanism for aging in ferroelectrics. Numerical results are given for the coupled problems of point defect migration and electrostatic energy relaxation in a 2D domain configuration. The peak values of the clamping pressure at domain walls are in the range of $10^6$ Pa, which corresponds to macroscopically observed coercive stresses in perovskite ferroelectrics. The effect is compared to mechanisms involving orientational reordering of defect dipoles in the bulk of domains. Domain clamping is significantly stronger in the drift mechanism than in the orientational picture for the same material parameters.
description: 24 pages, 12 figures, accepted to Physical Review B
Quasi-normal mode theory of the scattering matrix, enforcing fundamental constraints for truncated expansions
Creators: name: Benzaouia, Mohammed
name: Joannopoulos, John D.
name: Johnson, Steven G.
name: Karalis, Aristeidis
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We develop a quasi-normal mode theory (QNMT) to calculate a system's scattering $S$ matrix, simultaneously satisfying both energy conservation and reciprocity even for a small truncated set of resonances. It is a practical reduced-order (few-parameter) model based on the resonant frequencies and constant mode-to-port coupling coefficients, easily computed from an eigensolver without the need for QNM normalization. Furthermore, we show how low-$Q$ modes can be separated into an effective slowly varying background response $C$, giving an additional approximate formula for $S$, which is useful to describe general Fano-resonant phenomena. We demonstrate our formulation for both normal and fixed-angle oblique plane-wave incidence on various electromagnetic metasurfaces.
description: arXiv admin note: substantial text overlap with arXiv:2103.08866
Coulomb drag as a measure of trigonal warping in doped graphene
Creators: name: Narozhny, B. N.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: I suggest to use the effect of Coulomb drag between two closely positioned graphite monolayers (graphene sheets) for experimental measurement of the strength of weak non-linearities of the spectrum in graphene. I consider trigonal warping as a representative mechanism responsible for the drag effect. Since graphene is relatively defect-free, I evaluate the drag conductivity in the ballistic regime and find that it is proportional to the fourth power of the warping strength.
description: 4 pages, 1 figure
Compact CubeSat Gamma-Ray Detector for GRID Mission
Creators: name: Wen, Jia-Xing
name: Zheng, Xu-Tao
name: Yu, Jian-Dong
name: Che, Yue-Peng
name: Yang, Dong-Xin
name: Gao, Huai-Zhong
name: Jin, Yi-Fei
name: Long, Xiang-Yun
name: Liu, Yi-Hui
name: Xu, Da-Cheng
name: Zhang, Yu-Chong
name: Zeng, Ming
name: Tian, Yang
name: Feng, Hua
name: Zeng, Zhi
name: Cang, Ji-Rong
name: Wu, Qiong
name: Zhao, Zong-Qing
name: Zhang, Bin-Bin
name: An, Peng
name: collaboration, GRID
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Gamma-Ray Integrated Detectors (GRID) mission is a student project designed to use multiple gamma-ray detectors carried by nanosatellites (CubeSats), forming a full-time all-sky gamma-ray detection network that monitors the transient gamma-ray sky in the multi-messenger astronomy era. A compact CubeSat gamma-ray detector, including its hardware and firmware, was designed and implemented for the mission. The detector employs four Gd2Al2Ga3O12 : Ce (GAGG:Ce) scintillators coupled with four silicon photomultiplier (SiPM) arrays to achieve a high gamma-ray detection efficiency between 10 keV and 2 MeV with low power and small dimensions. The first detector designed by the undergraduate student team onboard a commercial CubeSat was launched into a Sun-synchronous orbit on October 29, 2018. The detector was in a normal observation state and accumulated data for approximately one month after on-orbit functional and performance tests, which were conducted in 2019.
description: final manuscript, 9 pages, 10 figures, published on NST
Attractors with Vanishing Central Charge
Creators: name: Bellucci, S.
name: Marrani, A.
name: Orazi, E.
name: Shcherbakov, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the Attractor Equations of particular $\mathcal{N}=2$, d=4 supergravity models whose vector multiplets' scalar manifold is endowed with homogeneous symmetric cubic special Kähler geometry, namely of the so-called $st^{2}$ and $stu$ models. In this framework, we derive explicit expressions for the critical moduli corresponding to non-BPS attractors with vanishing $\mathcal{N}=2$ central charge. Such formulæhold for a generic black hole charge configuration, and they are obtained without formulating any \textit{ad hoc} simplifying assumption. We find that such attractors are related to the 1/2-BPS ones by complex conjugation of some moduli. By uplifting to $\mathcal{N}=8$, d=4 supergravity, we give an interpretation of such a relation as an exchange of two of the four eigenvalues of the $\mathcal{N}=8$ central charge matrix $Z_{AB}$. We also consider non-BPS attractors with non-vanishing $\mathcal{Z}$; for peculiar charge configurations, we derive solutions violating the Ansatz usually formulated in literature. Finally, by group-theoretical considerations we relate Cayley's hyperdeterminant (the invariant of the stu model) to the invariants of the st^{2} and of the so-called t^{3} model.
description: 17 pages, LaTeX file
Relativistic Effects in Extreme Mass Ratio Gravitational Wave Bursts
Creators: name: Yunes, Nicolas
name: Sopuerta, Carlos F.
name: Rubbo, Louis J.
name: Holley-Bockelmann, Kelly
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Extreme mass ratio bursts (EMRBs) have been proposed as a possible source for future space-borne gravitational wave detectors, such as the Laser Interferometer Space Antenna (LISA). These events are characterized by long-period, nearly-radial orbits of compact objects around a central massive black hole. The gravitational radiation emitted during such events consists of a short burst, corresponding to periapse passage, followed by a longer, silent interval. In this paper we investigate the impact of including relativistic corrections to the description of the compact object's trajectory via a geodesic treatment, as well as including higher-order multipole corrections in the waveform calculation. The degree to which the relativistic corrections are important depends on the EMRB's orbital parameters. We find that relativistic EMRBs (v_{max}}/c > 0.25) are not rare and actually account for approximately half of the events in our astrophysical model. The relativistic corrections tend to significantly change the waveform amplitude and phase relative to a Newtonian description, although some of this dephasing could be mimicked by parameter errors. The dephasing over several bursts could be of particular importance not only to gravitational wave detection, but also to parameter estimation, since it is highly correlated to the spin of the massive black hole. Consequently, we postulate that if a relativistic EMRB is detected, such dephasing might be used to probe the relativistic character of the massive black hole and obtain information about its spin.
description: 13 pages, 8 figures, 2 tables. Replaced with version accepted for publication in the Ap. J
Generalized first-principles method to study near-field heat transfer mediated by Coulomb interaction
Creators: name: Zhu, Tao
name: Wang, Jian-Sheng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a general microscopic first-principles method to study the Coulomb-interaction-mediated heat transfer in the near field. Using the nonequilibrium Green's function formalism, we derive Caroli formulas for heat transfers between materials with translational invariance. The central physical quantities are the screened Coulomb potential and the spectrum function of polarizability. Within the random phase approximation, we calculate the polarizability using the linear response density functional theory and obtain the screened Coulomb potential from a retarded Dyson equation. We show that the heat transfer mediated by the Coulomb interaction is consistent with that of the $p$-polarized evanescent waves which dominate the heat transfer in the near field. We adopt single-layer graphene as an example to calculate heat transfers between two parallel sheets separated by a vacuum gap $d$. Our results show a saturation of heat flux at the extreme near field which is different from the reported $1/d$ dependence for local response functions. The calculated heat flux is up to $5\times10^4$ times more than the black-body limit, and a $1/d^2$ dependence is shown at large separations. From the spectrum of energy current density, we infer that the near-field enhancement of heat transfer stems from electron transitions around the Fermi energy. With a uniform strain, the heat flux increases for most of the distances while a negative correlation is shown at the moderate field. Our method is valid for inhomogeneous materials in which the macroscopic response function used in conventional theory of fluctuational electrodynamics would fail at the subnanometer scale.
description: 7 pages, 4 figures
Parametric-resonance entangling gates with a tunable coupler
Creators: name: Sete, Eyob A.
name: Didier, Nicolas
name: Chen, Angela Q.
name: Kulshreshtha, Shobhan
name: Manenti, Riccardo
name: Poletto, Stefano
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-fidelity parametric gates have been demonstrated with superconducting qubits via rf flux modulation of the qubit frequency. The modulation however leads to renormalization of the bare qubit-qubit coupling, thereby reducing the gate speed. Here, we realize a parametric-resonance gate, which is activated by bringing the average frequency of the modulated qubit in resonance with a static-frequency qubit while approximately retaining the bare qubit-qubit coupling. The activation of parametric-resonance gates does not depend on the frequency of modulation, allowing us to choose the modulation frequencies and avoid frequency collisions. Moreover, we show that this approach is compatible with tunable coupler architectures, which reduce always-on residual couplings. Using these techniques, we demonstrate iSWAP and CZ gates between two qubits coupled via a tunable coupler with average process fidelities as high as $99.3\%$ and $97.9\%$, respectively. The flexibility in activating parametric-resonance gates combined with a tunable coupler architecture provides a pathway for building large-scale quantum computers.
description: 15 pages, 11 figures and one table. Published version
Removal of instabilities of the higher derivative theories in the light of antilinearity
Creators: name: Paul, Biswajit
name: Dhar, Himangshu
name: Saha, Biswajit
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Theories with higher derivatives involve linear instabilities in the Hamiltonian commonly known as Ostrogradski ghosts and can be viewed as a very serious problem during quantization. To cure {this} , we have considered the properties of antilinearty that can be found inherently in the non-Hermitian Hamiltonians. Owing to the existence of antilinearity, we can construct an operator, called the $V$-operator, which acts as an intertwining operator between the Hamiltonian and its hermitian conjugate. We have used this $V$-operator to remove the linear momenta term from the higher derivative Hamiltonian by making it non-Hermitian in the first place via an isospectral similarity transformation. The final form of the Hamiltonian is free from the Ostrogradski ghosts under some restriction on the mass term.
description: 12 pages, Latex, updated version
Cooperative Secondary Authorization Recycling
Creators: name: Wei, Qiang
name: Ripeanu, Matei
name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2007
Subjects: CSAR
SAAM
JAMES
authorization recycling
cooperation
Engineering Security Mechanisms

description: As distributed applications such as Grid and enterprise systems scale up and become increasingly complex, their authorization infrastructures—based predominantly on the request-response paradigm—are facing challenges in terms of fragility and poor scalability. We propose an approach where each application server caches previously received authorizations at its secondary decision point and shares them with other application servers to mask authorization server failures and network delays.  This talk presents the design of our cooperative secondary authorization recycling system and its evaluation using simulation and prototype implementation. The results demonstrate that our approach improves the availability of authorization infrastructures while preserving their performance characteristics. Specifically, by sharing authorizations, the cache hit rate—an indirect metric of availability—can reach 70%, even when only 10% of authorizations are cached. Depending on the deployment scenario, the performance in terms of the average time for authorizing an application request can be reduced by up to 30%.
Alkali-silica reaction products and cracks: X-ray micro-tomography-based analysis of their spatial-temporal evolution at a mesoscale
Creators: name: Shakoorioskooie, Mahdieh
name: Griffa, Michele
name: Leemann, Andreas
name: Zboray, Robert
name: Lura, Pietro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this study, we propose a laboratory-scale methodology, based on X-ray micro-tomography and caesium (Cs) as a contrast agent, to advance the understanding of cracking due to alkali-silica reaction (ASR) in concrete. The methodology allows achieving a completely non-destructive and time-lapse characterization of the spatial-temporal patterns of both the cracks and the ASR products. While Cs addition slightly accelerated the ASR kinetics, the crack pat-terns, with and without Cs addition, were statistically equivalent. Cracks with ASR products appeared first in the aggregates, close to the interface with the cement paste. They propagated afterwards towards the aggregates interior. Some products were then extruded for several mm into air voids and cracks in the cement paste. This process suggests that, in the early stage, the ASR products may be a low-viscosity gel that can flow away from the source aggregate and may settle later elsewhere as a rigid phase, upon calcium uptake.
Weak local rules for planar octagonal tilings
Creators: name: Bédaride, Nicolas
name: Fernique, Thomas
Publisher: name: arXiv
Year: 2015
Subjects: subject: Dynamical Systems (math.DS)
subject: Mathematical Physics (math-ph)
subject: Combinatorics (math.CO)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: F.1.1
subject: 37B50, 52C20, 52C23, 37B10

description: We provide an effective characterization of the planar octagonal tilings which admit weak local rules. As a corollary, we show that they are all based on quadratic irrationalities, as conjectured by Thang Le in the 90s.
description: 23 pages, 6 figures
On the Imbalance of the Security Problem Space and its Expected Consequences
Creators: name: Beznosov, Konstantin
name: Beznosova, Olga
Publisher: name: Zenodo
Year: 2007
Subjects: Computer Security
Social Factors
Organizational Factors
Usable Security
HOT Admin

description: This paper considers the attacker-defender game in the field of computer security as a three-dimensional phenomenon. The decomposition of the problem space into technological, human, and social factors enabled us to analyze the concentration of public research efforts by defenders. Our analysis suggests that over 94% of the public research in computer security has been concentrated on technological advances. Yet attackers seem to employ more and more human and social factors in their attacks. As the arms race in computer security progresses, social factors may become or already are increasingly important. The side that capitalizes on them sooner may gain the competitive advantage. Drawing on recent results in the organizational theory, sociology, and political science, we discuss avenues for investigating the social dimension by the defenders.
Evolution of statistical analysis in empirical software engineering research: Current state and steps forward
Creators: name: Neto, Francisco Gomes de Oliveira
name: Torkar, Richard
name: Feldt, Robert
name: Gren, Lucas
name: Furia, Carlo A.
name: Huang, Ziwei
Publisher: name: arXiv
Year: 2017
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Software engineering research is evolving and papers are increasingly based on empirical data from a multitude of sources, using statistical tests to determine if and to what degree empirical evidence supports their hypotheses. To investigate the practices and trends of statistical analysis in empirical software engineering (ESE), this paper presents a review of a large pool of papers from top-ranked software engineering journals. First, we manually reviewed 161 papers and in the second phase of our method, we conducted a more extensive semi-automatic classification of papers spanning the years 2001--2015 and 5,196 papers. Results from both review steps was used to: i) identify and analyze the predominant practices in ESE (e.g., using t-test or ANOVA), as well as relevant trends in usage of specific statistical methods (e.g., nonparametric tests and effect size measures) and, ii) develop a conceptual model for a statistical analysis workflow with suggestions on how to apply different statistical methods as well as guidelines to avoid pitfalls. Lastly, we confirm existing claims that current ESE practices lack a standard to report practical significance of results. We illustrate how practical significance can be discussed in terms of both the statistical analysis and in the practitioner's context.
description: journal submission, 34 pages, 8 figures
On the road to percent accuracy V: the non-linear power spectrum beyond $Λ$CDM with massive neutrinos and baryonic feedback
Creators: name: Bose, Benjamin
name: Wright, Bill S.
name: Cataneo, Matteo
name: Pourtsidou, Alkistis
name: Giocoli, Carlo
name: Lombriser, Lucas
name: McCarthy, Ian G.
name: Baldi, Marco
name: Pfeifer, Simon
name: Xia, Qianli
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In the context of forthcoming galaxy surveys, to ensure unbiased constraints on cosmology and gravity when using non-linear structure information, percent-level accuracy is required when modelling the power spectrum. This calls for frameworks that can accurately capture the relevant physical effects, while allowing for deviations from $Λ$CDM. Massive neutrino and baryonic physics are two of the most relevant such effects. We present an integration of the halo model reaction frameworks for massive neutrinos and beyond-$Λ$CDM cosmologies. The integrated halo model reaction, combined with a pseudo power spectrum modelled by HMCode2020 is then compared against $N$-body simulations that include both massive neutrinos and an $f(R)$ modification to gravity. We find that the framework is 4% accurate down to at least $k\approx 3 \, h/{\rm Mpc}$ for a modification to gravity of $|f_{\rm R0}|\leq 10^{-5}$ and for the total neutrino mass $M_ν\equiv \sum m_ν\leq 0.15$ eV. We also find that the framework is 4% consistent with EuclidEmulator2 as well as the Bacco emulator for \B{most of the considered} $νw$CDM cosmologies down to at least $k \approx 3 \, h$/Mpc. Finally, we compare against hydrodynamical simulations employing HMCode2020's baryonic feedback modelling on top of the halo model reaction. For $νΛ$CDM cosmologies we find 2% accuracy for $M_ν\leq 0.48$eV down to at least $k\approx 5h$/Mpc. Similar accuracy is found when comparing to $νw$CDM hydrodynamical simulations with $M_ν= 0.06$eV. This offers the first non-linear, theoretically general means of accurately including massive neutrinos for beyond-$Λ$CDM cosmologies, and further suggests that baryonic, massive neutrino and dark energy physics can be reliably modelled independently.
description: 13 pages, 11 figures. MNRAS accepted version. Download ReACT: https://github.com/nebblu/ReACT/tree/react_with_neutrinos
Validation of an urban canyon radiation model for nocturnal long-wave radiative fluxes and the effect of surface geometry on cooling in urban canyons
Creators: name: Voogt, James Adrian
Publisher: name: University of British Columbia
Year: 2010

description: The urban canyon radiation model of Arnfield (1976, 1982) is validated using measurements of long-wave fluxes taken within a scale urban canyon constructed from concrete building blocks. A custom-designed traversing system allowed miniature radiometers to be automatically moved around the perimeter of a canyon cross-section thereby providing for the validation of individual model grid-points. Measured model input consists of surface temperatures obtained using fine wire themocouples, incident long-wave radiation at the canyon top, and emissivity of canyon materials. Tests were conducted to establish the expected accuracy and precision of the input data. Surface temperature data were filtered to remove a noise component. A probable error analysis of all measured model input and validation data is made. Sensitivity tests of the model to variations in input data are presented. Surface temperature is the dominant control under the conditions tested. Model-calculated view-factors are shown to be in error for adjacent corner points and are replaced with view-factors calculated using equations derived from the Nusselt Unit Sphere method (Steyn, pers. comm.) Validation results for a range of canyon height-to-width ratios, meteorological conditions and model parameters are presented. Excellent agreement between modelled and measured fluxes is obtained for points on the canyon floor and top. The agreement for fluxes at points on the canyon walls is generally good but is shown to suffer from errors in sensor orientation relative to the canyon walls. Use of the Unsworth and Monteith (1975) radiance distribution improves model performance statistics for incident and net long-wave radiation. Four different estimates of surface temperature are used as model input in place of the measured values to investigate the differences in the model output. Surface temperature-based estimates are found to be superior to those based upon air temperature. The use of unmodified screen-level air temperatures measured at Vancouver Airport produces the poorest agreement. The temporal and spatial variation of in-canyon temperatures and radiation are presented for three canyon height-to-width ratios. The canyon geometry is shown to significantly reduce the surface cooling on the canyon floor compared to an open site under ideal radiative cooling conditions. Results are compared to previous results from scale models (Oke, 1981) and field studies (Oke and Maxwell, 1975; Hogstrdm et al., 1978). . Atmospheric controls of incident long-wave radiation, wind speed and direction are also shown to affect the observed cooling.
First Constraints on Nuclear Coupling of Axionlike Particles from the Binary Neutron Star Gravitational Wave Event GW170817
Creators: name: Zhang, Jun
name: Lyu, Zhenwei
name: Huang, Junwu
name: Johnson, Matthew C.
name: Sagunski, Laura
name: Sakellariadou, Mairi
name: Yang, Huan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Light axion fields, if they exist, can be sourced by neutron stars due to their coupling to nuclear matter, and play a role in binary neutron star mergers. We report on a search for such axions by analysing the gravitational waves from the binary neutron star inspiral GW170817. We find no evidence of axions in the sampled parameter space. The null result allows us to impose constraints on axions with masses below $10^{-11} {\rm eV}$ by excluding the ones with decay constants ranging from $1.6\times10^{16} {\rm GeV}$ to $10^{18} {\rm GeV}$ at $3σ$ confidence level. Our analysis provides the first constraints on axions from neutron star inspirals, and rules out a large region in parameter space that has not been probed by the existing experiments.
description: 7 pages, 2 figures, title changed, Fig.1 and references updated, v2 matches version published in PRL
A connection between tests for absolute convergence of infinite series, or how to be fair
Creators: name: Rayskin, Victoria
Publisher: name: arXiv
Year: 2018
Subjects: subject: History and Overview (math.HO)
subject: FOS: Mathematics
subject: 40A05, 97I30

description: The Ratio Test and the Root Test for absolute convergence/divergence of series of numbers $\sum_{n=0}^{\infty}a_n$ are frequently discussed and proved independently in Calculus courses.
 The Root Test is stronger (verifies convergence for more series) than the Ratio Test. This relation inspires introduction of some intermediate strength tests (stronger than the Ratio Test and weaker than the Root Test) that we call Power Mean Tests (they, in particular, include the Arithmetic Mean Test). We show the connection between the Root, the Power Mean and the Ratio Tests. We also note that all these tests are related to the test that we formulate and call Generalized $f$-mean Test (or Kolmogorov-Nagumo-de Finetti mean Test). We provide an example of an infinite series, where the Arithmetic Mean test is the test that should be used for convergence verification, because the Root and the Ratio Tests are not easy to apply.
 We conclude this work with the statement emphasizing why it is ``fair'' to include the summarizing Corollary 3.1 in our Calculus course.
Entanglement transport and a nanophotonic interface for atoms in optical tweezers
Creators: name: Đorđević, Tamara
name: Samutpraphoot, Polnop
name: Ocola, Paloma L.
name: Bernien, Hannes
name: Grinkemeyer, Brandon
name: Dimitrova, Ivana
name: Vuletić, Vladan
name: Lukin, Mikhail D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The realization of an efficient quantum optical interface for multi-qubit systems is an outstanding challenge in science and engineering. Using two atoms in individually-controlled optical tweezers coupled to a nanofabricated photonic crystal cavity, we demonstrate entanglement generation, fast non-destructive readout, and full quantum control of atomic qubits. The entangled state is verified in free space after being transported away from the cavity by encoding the qubits into long-lived states and using dynamical decoupling. Our approach bridges quantum operations at an optical link and in free space with a coherent one-way transport, potentially enabling an integrated optical interface for atomic quantum processors.
description: Supplementary materials at the end; 16 pages, 14 figures
A Method to Assess and Argue for Practical Significance in Software Engineering
Creators: name: Torkar, Richard
name: Furia, Carlo A.
name: Feldt, Robert
name: Neto, Francisco Gomes de Oliveira
name: Gren, Lucas
name: Lenberg, Per
name: Ernst, Neil A.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: A key goal of empirical research in software engineering is to assess practical significance, which answers whether the observed effects of some compared treatments show a relevant difference in practice in realistic scenarios. Even though plenty of standard techniques exist to assess statistical significance, connecting it to practical significance is not straightforward or routinely done; indeed, only a few empirical studies in software engineering assess practical significance in a principled and systematic way.
 In this paper, we argue that Bayesian data analysis provides suitable tools to assess practical significance rigorously. We demonstrate our claims in a case study comparing different test techniques. The case study's data was previously analyzed (Afzal et al., 2015) using standard techniques focusing on statistical significance. Here, we build a multilevel model of the same data, which we fit and validate using Bayesian techniques. Our method is to apply cumulative prospect theory on top of the statistical model to quantitatively connect our statistical analysis output to a practically meaningful context. This is then the basis both for assessing and arguing for practical significance.
 Our study demonstrates that Bayesian analysis provides a technically rigorous yet practical framework for empirical software engineering. A substantial side effect is that any uncertainty in the underlying data will be propagated through the statistical model, and its effects on practical significance are made clear.
 Thus, in combination with cumulative prospect theory, Bayesian analysis supports seamlessly assessing practical significance in an empirical software engineering context, thus potentially clarifying and extending the relevance of research for practitioners.
description: 13 pages, 9 figures, 3 tables. Minor rev update
Optimal Positioning of PMUs for Fault Detection and Localization in Active Distribution Networks
Creators: name: Conte, F.
name: Gabriele, B.
name: Schiapparelli, G. -P.
name: Silvestro, F.
name: Bossi, C.
name: Cabiati, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper considers the problem of fault detection and localization in active distribution networks using PMUs. The proposed algorithm consists in computing a set of weighted least squares state estimates whose results are used to detect, characterize and localize the occurrence of a fault. Moreover, a criteria to minimize the number of PMUs required to correctly perform the proposed algorithm is defined. Such a criteria, based on system observability conditions, allows the design of an optimization problem to set the positions of PMUs along the grid, in order to get the desired fault localization resolution. The performances of the strategy are tested via simulations on a benchmark distribution system.
Generalized prolate spheroidal functions: algorithms and analysis
Creators: name: Greengard, Philip
Publisher: name: arXiv
Year: 2018
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: Generalized prolate spheroidal functions (GPSFs) arise naturally in the study of bandlimited functions as the eigenfunctions of a certain truncated Fourier transform. In one dimension, the theory of GPSFs (typically referred to as prolate spheroidal wave functions) has a long history and is fairly complete. Furthermore, more recent work has led to the development of numerical algorithms for their computation and use in applications. In this paper we consider the more general problem, extending the one dimensional analysis and algorithms to the case of arbitrary dimension. Specifically, we introduce algorithms for efficient evaluation of GPSFs and their corresponding eigenvalues, quadrature rules for bandlimited functions, formulae for interpolation via GPSF expansion, and various analytical properties of GPSFs. We illustrate the numerical and analytical results with several numerical examples.
Bayesian Data Analysis in Empirical Software Engineering Research
Creators: name: Furia, Carlo A.
name: Feldt, Robert
name: Torkar, Richard
Publisher: name: arXiv
Year: 2018
Subjects: subject: Software Engineering (cs.SE)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Statistics comes in two main flavors: frequentist and Bayesian. For historical and technical reasons, frequentist statistics have traditionally dominated empirical data analysis, and certainly remain prevalent in empirical software engineering. This situation is unfortunate because frequentist statistics suffer from a number of shortcomings---such as lack of flexibility and results that are unintuitive and hard to interpret---that curtail their effectiveness when dealing with the heterogeneous data that is increasingly available for empirical analysis of software engineering practice.
 In this paper, we pinpoint these shortcomings, and present Bayesian data analysis techniques that provide tangible benefits---as they can provide clearer results that are simultaneously robust and nuanced. After a short, high-level introduction to the basic tools of Bayesian statistics, we present the reanalysis of two empirical studies on the effectiveness of automatically generated tests and the performance of programming languages. By contrasting the original frequentist analyses with our new Bayesian analyses, we demonstrate the concrete advantages of the latter. To conclude we advocate a more prominent role for Bayesian statistical techniques in empirical software engineering research and practice.
description: To appear in IEEE Transactions on Software Engineering
Canonical projection tilings defined by patterns
Creators: name: Bédaride, Nicolas
name: Fernique, Thomas
Publisher: name: arXiv
Year: 2018
Subjects: subject: Dynamical Systems (math.DS)
subject: Discrete Mathematics (cs.DM)
subject: Combinatorics (math.CO)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 52C23, 37B50

description: We give a necessary and sufficient condition on a $d$-dimensional affine subspace of $\mathbb{R}^n$ to be characterized by a finite set of patterns which are forbidden to appear in its digitization. This can also be stated in terms of local rules for canonical projection tilings, or subshift of finite type. This provides a link between algebraic properties of affine subspaces and combinatorics of their digitizations. The condition relies on the notion of {\em coincidence} and can be effectively checked. As a corollary, we get that only algebraic subspaces can be characterized by patterns.
description: 24 pages, 12 figures
Designing of non-circular gears
Creators: name: Zarębski, Igor
name: Sałaciński, Tadeusz
Publisher: name: Polish Academy of Sciences, Committee on Machine Building
Year: 2019
Subjects: noncircular gears designing
non-circular

description: In this paper, the authors present methods for designing of non-circular gears, including internal and external gears with spur or helical teeth. Technology related issues that determine tooth profile calculation algorithm are described. The results presented in this paper can become groundwork for further investigations of other particular properties of non-circular gears, similar to investigations of spur, helical and bevel gears. Examples of such properties include kinematics and application of special purpose gears or issues related to strength, dynamics, tribology, etc.
Tower power for $S$-adics
Creators: name: Bédaride, Nicolas
name: Hilion, Arnaud
name: Lustig, Martin
Publisher: name: arXiv
Year: 2019
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37B10, 37A25, 37E25

description: We explain and restate the results from our recent paper arXiv:1503.08000.v3 in standard language for substitutions and $S$-adic systems in symbolic dynamics. We then produce as rather direct application an $S$-adic system (with finite set of substitutions $S$ on $d$ letters) that is minimal and has $d$ distinct ergodic probability measures.
 As second application we exhibit a formula that allows an efficient practical computation of the cylinder measure $μ([w])$, for any word $w \in \cal A^*$ and any invariant measure $μ$ on the subshift $X_σ$ defined by any everywhere growing but not necessarily primitive or irreducible substitution $σ: \cal A^* \to \cal A^*$. Several examples are considered in detail, and model computations are presented.
description: 20 pages. See also arXiv:1503.08000.v3
A novel requirement for the X-chromosome in P-M hybrid dysgenesis and the interaction of the garnet and enhancer of garnet loci in Drosophila melanogaster
Creators: name: Wennberg, Richard Arnold
Publisher: name: University of British Columbia
Year: 2010

description: The discovery of extreme mutability around the g. locus of Drosophila melanogaster in a certain lab strain, S6-1, led to an investigation of the nature of this phenomenon and any possible relationship it had with the well described P-M hybrid dysgenesis mutator system. Southern gel analysis showed the S6-1 strain to contain P element homology and dysgenic crosses involving this P-strain showed mutability in the germline of the F₁. An unexpected finding was the requirement for the presence of the S6-1 X-chromosome in F₁ dysgenic males in order to produce the germline mutability. In situ hybridization to polytene chromosomes showed the S6-1 strain to have a number of P sites, the majority of which were on the X-chromosome (app. 20/33). These results indicated that the only complete P element or elements were confined to the X-chromosome. The presence of an unexpected third class of orange-eyed males in the F₂ progeny of the cross: S6-1 males x g² females led to the isolation of an enhancer of garnet locus, (e(g), located in the distal region of the S6-1 X-chromosome. This study included an investigation into the nature of the interaction between the e(g) locus and the g; locus and other autosomal loci. The enhancer was found to be specific to the g. locus, and, more specifically, to certain spontaneous alleles located to one end of the fine structure g. locus map. A description is given of the isolation and preparation of a P-induced garnet mutation for molecular analysis.
title: Peer interaction in the Adult English as a Foreign language classroom
title: Using Social Discourse to Establish Peer Relationships
titleType: Subtitle
Creators: name: Preciado Sanchez, Ana Monica
Publisher: name: Lancaster University
Year: 2021
Subjects: comity, patterns of interaction, LREs, classroom tasks, sociocultural theory

description: The purpose of this study is to investigate how adult learners of English as a foreign language mediate language learning opportunities while working together in the classroom. Specifically, the study addresses: (i) how learners use language to create comity, which refers to the interactional talk aimed at establishing and maintaining friendly relations and positive rapport (Aston, 1988, 1993), (ii) what types of interactional patterns students create while working together (iii) how the use of social discourse offers opportunities for language learning. The study is classroom-based, and it was conducted in a university EFL classroom in Mexico for four weeks. Twenty-four learners (i.e., twelve pairs) participated in the study, and data were collected while they worked with five language tasks. The data comprise transcripts of audio-recorded pair talk, detailed observation notes, and interviews with participants. Drawing from sociocultural theory, this study examines the moment-to-moment discourse to identify social discourse moves of social inquiry, solidarity, and support and language-related episodes produced in the interactions. Findings show how learners used discourse to express and maintain support and solidarity, allowing them to engage in pair discussions to complete the language tasks. Social inquiry provided a space for students to get to know each other better, thus creating affective bonds and a feeling of trust towards the partner. The results also show that learners created four different patterns of interaction (collaborative, dominant/dominant, expert/novice, dominant/passive). The pairs predominantly established a collaborative interaction, which has been shown to be more conducive to learning (Storch, 2001, Watanabe, 2008). The findings suggest that the students who were more likely to use discourse to express support, solidarity, and engage in social inquiry, created a collaborative and expert/novice pattern of interaction. Consequently, the study shows how establishing comity in the language classroom promotes a more collaborative interaction between peers and supports learning in the context of peer interaction.
Desingularizing positive scalar curvature 4-manifolds
Creators: name: Kazaras, Demetre
Publisher: name: arXiv
Year: 2019
Subjects: subject: Differential Geometry (math.DG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 53C21, 53D23, 53C80, 57R90

description: We show that the bordism group of closed 3-manifolds with positive scalar curvature (psc) metrics is trivial by explicit methods. Our constructions are derived from scalar-flat K{ä}hler ALE surfaces discovered by Lock-Viaclovsky. Next, we study psc 4-manifolds with metric singularities along points and embedded circles. Our psc null-bordisms are essential tools in a desingularization process developed by Li-Mantoulidis. This allows us to prove a non-existence result for singular psc metrics on enlargeable 4-manifolds with uniformly Euclidean geometry. As a consequence, we obtain a positive mass theorem for asymptotically flat 4-manifolds with non-negative scalar curvature and low regularity.
description: The proof of Lemma 2 was improved