cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
D-branes in overcritical electric fields
Creators: name: Dorn, Harald
name: Salizzoni, Mario
name: Torrielli, Alessandro
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We collect some arguments for treating a D-brane with overcritical electric field as a well-posed initial condition for a D-brane decay. Within the field theoretical toy model of Minahan and Zwiebach we give an estimate for the condensates of the related infinite tower of tachyonic excitations.
description: 11 pages, 2 figures; references and comments added, version to appear in PRD
Flavor quark at high temperature from a holographic model
Creators: name: Ghoroku, Kazuo
name: Sakaguchi, Tomohiko
name: Uekusa, Nobuhiro
name: Yahiro, Masanobu
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Gauge theory with light flavor quark is studied by embedding a D7 brane in a deconfinement phase background newly constructed. We find a phase transition by observing a jump of the vacuum expectation value of quark bilinear and also of the derivative of D7 energy at a critical temperature. For the model considered here, we also study quark-antiquark potential to see some possible quark-bound states and other physical quantities in the deconfinement phase.
description: 17 pages, 11 figures
Scale and isolation sensitivity of diphoton distributions at the LHC
Creators: name: Gehrmann, Thomas
name: Glover, Nigel
name: Huss, Alexander
name: Whitehead, James
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Precision measurements of diphoton distributions at the LHC display some tension with theory predictions, obtained at next-to-next-to-leading order (NNLO) in QCD. We revisit the theoretical uncertainties arising from the approximation of the experimental photon isolation by smooth-cone isolation, and from the choice of functional form for the renormalisation and factorisation scales. We find that the resulting variations are substantial overall, and enhanced in certain regions. We discuss the infrared sensitivity at the cone boundaries in cone-based isolation in related distributions. Finally, we compare predictions made with alternative choices of dynamical scale and isolation prescriptions to experimental data from ATLAS at 8 TeV, observing improved agreement. This contrasts with previous results, highlighting that scale choice and isolation prescription are potential sources of theoretical uncertainty that were previously underestimated.
description: 35 pages, 17 figures. Additional discussion of isolation uncertainty at the end of s2.1. Version accepted for publication by JHEP
Promises and Realities: Working on Digital Platforms
Creators: name: MacQuarie, Julius-Cezar
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 440199
subject: Anthropology not elsewhere classified

description: Glovo, Uber, or Bolt are just some of the names that have become known in Romania in a very short time, especially in the context of the COVID-19 pandemic. But a less discussed phenomenon is what it means to be a delivery person or a courier when your manager is an algorithm that monitors your every move and checks you at every step. In other words, what does it mean to be a worker on a digital platform and part of the “platform economy”? Are these workers really their own bosses? And do they really work when and as much as they want? In this text and podcast, I talk about the lives of night workers hired by online ordering platforms and transport and courier services in big cities like Bucharest, Brașov, Cluj, Iași, and Timișoara, the so-called “siliconised cities.” Bolt or Uber drivers are the people who work “behind the scenes” 24/7 (twenty-four hours per day, seven days per week). But those who work in a different temporal rhythm, nocturnal, are invisible to the majority of society who work during the day. That is why nightshift workers have a low sense of the value of their services compared to workers in professional jobs in Romania, and they feel a lack of respect from consumers who use their services. In other words, I will tell you about the inequalities that appear and deepen in the social fabric of the “siliconised cities.”
Tomographic reconstruction of the runaway distribution function in TCV using multispectral synchrotron images
Creators: name: Wijkamp, T. A.
name: Perek, A.
name: Decker, J.
name: Duval, B.
name: Hoppe, M.
name: Papp, G.
name: Sheikh, U. A.
name: Classen, I. G. J.
name: Jaspers, R. J. E.
name: team, the TCV
name: team, the EUROfusion MST1
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Synchrotron radiation observed in a quiescent TCV runaway discharge is studied using filtered camera images targeting three distinct wavelength intervals. Through the tomographic SART procedure the high momentum, high pitch angle part of the spatial and momentum distribution of these relativistic particles is reconstructed. Experimental estimates of the distribution are important for verification and refinement of formation-, decay- and transport-models underlying runaway avoidance and mitigation strategy design. Using a test distribution it is demonstrated that the inversion procedure provides estimates accurate to within a few tens of percent in the region of phase-space contributing most to the synchrotron image. We find that combining images filtered around different parts of the emission spectrum widens the probed part of momentum-space and reduces reconstruction errors. Next, the SART algorithm is used to obtain information on the spatiotemporal runaway momentum distribution in a selected TCV discharge. The momentum distribution is found to relax towards an avalanche-like exponentially decaying profile. Anomalously high pitch angles and a radial profile increasing towards the edge are found for the most strongly emitting particles in the distribution. Pitch angle scattering by toroidal magnetic field ripple is consistent with this picture. An alternative explanation is the presence of high frequency instabilities in combination with the formation of a runaway shell at the edge of the plasma.
description: 18 pages, 13 figures, submitted to Nuclear Fusion
Mid-infrared photometry of the T Tauri triple system with kernel phase interferometry
Creators: name: Kammerer, J.
name: Kasper, M.
name: Ireland, M. J.
name: Köhler, R.
name: Laugier, R.
name: Martinache, F.
name: Siebenmorgen, R.
name: Ancker, M. E. van den
name: van Boekel, R.
name: Herbst, T. M.
name: Pantin, E.
name: Käufl, H. -U.
name: de la Roche, D. J. M. Petit dit
name: Ivanov, V. D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: T Tauri has long been the prototypical young pre-main-sequence star. However, it has now been decomposed into a triple system with a complex disk and outflow geometry. We aim to measure the brightness of all three components of the T Tauri system (T Tau N, T Tau Sa, T Tau Sb) in the mid-infrared in order to obtain photometry around the $\sim 9.7~μm$ silicate feature. This allows us to study their variability and to investigate the distribution of dust and the geometry of circumstellar and circumbinary disks in this complex system. We observe T Tauri with the VLT/VISIR-NEAR instrument. With kernel phase interferometry post-processing of the data, and using the astrometric positions of all three components from VLT/SPHERE, we measure the three components' individual brightnesses (including the southern binary at an angular separation down to $\sim 0.2~λ/D$) and obtain their photometry. In order to validate our methods, we simulate and recover mock data of the T Tauri system using the observed reference point-spread function of HD 27639. We find that T Tau N is rather stable and shows weak silicate emission, while T Tau Sa is highly variable and shows prominent silicate absorption. T Tau Sb became significantly fainter compared to data from 2004 and 2006, suggesting increased extinction by dust. The precision of our photometry is limited by systematic errors, which is consistent with previous studies using kernel phase interferometry. Our results confirm the complex scenario of misaligned disks in the T Tauri system that had been observed previously, and they are in agreement with the recently observed dimming of T Tau Sb in the near-infrared. Our mid-infrared photometry supports the interpretation that T Tau Sb has moved behind the dense region of the Sa-Sb circumbinary disk on its tight orbit around Sa, therefore suffering increased extinction.
description: 14 pages, 7 figures, accepted for publication in Astronomy & Astrophysics
Operator Approach to Boundary Liouville Theory
Creators: name: Dorn, Harald
name: Jorjadze, George
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose new methods for calculation of the discrete spectrum, the reflection amplitude and the correlation functions of boundary Liouville theory on a strip with Lorentzian signature. They are based on the structure of the vertex operator $V=e^{-ϕ}$ in terms of the asymptotic operators. The methods first are tested for the particle dynamics in the Morse potential, where similar structures appear. Application of our methods to boundary Liouville theory reproduces the known results obtained earlier in the bootstrap approach, but there can arise a certain extension when the boundary parameters are near to critical values. Namely, in this case we have found up to four different equidistant series of discrete spectra, and the reflection amplitude is modified respectively.
description: 45 pages, 5 figures, extented subsection 4.3.2, related minor changes in subsections 3.3 and 4.2
Noise Sensitivity-Based Energy Efficient and Robust Adversary Detection in Neural Networks
Creators: name: Sterneck, Rachel
name: Moitra, Abhishek
name: Panda, Priyadarshini
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Neural networks have achieved remarkable performance in computer vision, however they are vulnerable to adversarial examples. Adversarial examples are inputs that have been carefully perturbed to fool classifier networks, while appearing unchanged to humans. Based on prior works on detecting adversaries, we propose a structured methodology of augmenting a deep neural network (DNN) with a detector subnetwork. We use $\textit{Adversarial Noise Sensitivity}$ (ANS), a novel metric for measuring the adversarial gradient contribution of different intermediate layers of a network. Based on the ANS value, we append a detector to the most sensitive layer. In prior works, more complex detectors were added to a DNN, increasing the inference computational cost of the model. In contrast, our structured and strategic addition of a detector to a DNN reduces the complexity of the model while making the overall network adversarially resilient. Through comprehensive white-box and black-box experiments on MNIST, CIFAR-10, and CIFAR-100, we show that our method improves state-of-the-art detector robustness against adversarial examples. Furthermore, we validate the energy efficiency of our proposed adversarial detection methodology through an extensive energy analysis on various hardware scalable CMOS accelerator platforms. We also demonstrate the effects of quantization on our detector-appended networks.
description: Accepted in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (TCAD), 2021
Variational approach to dequantization
Creators: name: Mosna, Ricardo A.
name: Hamilton, Ian P.
name: Site, Luigi Delle
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We present a dequantization procedure based on a variational approach whereby quantum fluctuations latent in the quantum momentum are suppressed. This is done by adding generic local deformations to the quantum momentum operator which give rise to a deformed kinetic term quantifying the amount of ``fuzzyness'' caused by such fluctuations. Considered as a functional of such deformations, the deformed kinetic term is shown to possess a unique minimum which is seen to be the classical kinetic energy. Furthermore, we show that extremization of the associated deformed action functional introduces an essential nonlinearity to the resulting field equations which are seen to be the classical Hamilton-Jacobi and continuity equations. Thus, a variational procedure determines the particular deformation that has the effect of suppressing the quantum fluctuations, resulting in dequantization of the system.
description: 6 pages, 1 figure. v2: changes in presentation and content
A multiwavelength radial velocity search for planets around the brown dwarf LP 944-20
Creators: name: Martin, E. L.
name: Guenther, E.
name: Osorio, M. R. Zapatero
name: Bouy, H.
name: Wainscoat, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The nearby brown dwarf LP 944-20 has been monitored for radial velocity variability at optical and near-infrared wavelengths using the VLT/UVES and the Keck/NIRSPEC spectrographs, respectively. The UVES radial velocity data obtained over 14 nights spanning a baseline of 841 days shows significant variability with an amplitude of 3.5 km s$^{-1}$. The periodogram analysis of the UVES data indicates a possible period between 2.5 hours and 3.7 hours, which is likely due to the rotation of the brown dwarf. However, the NIRSPEC data obtained over 6 nights shows an rms dispersion of only 0.36 km s$^{-1}$ and do not follow the periodic trend. These results indicate that the variability seen with UVES is likely to be due to rotationally modulated inhomogeneous surface features. We suggest that future planet searches around very low-mass stars and brown dwarfs using radial velocities will be better conducted in the near-infrared than in the optical.
description: accepted by ApJ Letters
title: Extreme Weather and Low-Income Household Finance: Evidence from Payday Loans
Creators: name: Xie, Shihan
name: Xie, Victoria Wenxin
name: zhang, xu
Publisher: name: Bank of Canada
Year: 2024

description: This paper explores the impact of extreme weather exposures on the financial outcomes of low-income households. Using a novel dataset comprising individual-level payday loan applications and loan-level information, we find that extreme temperature days—both hot and cold—lead to surges in demand for payday loans. An increase in the number of days with extreme heat results in an increase in delinquency and default rates and a reduction of total credit issued, indicating a contraction in loan supply. These effects are especially noticeable for online payday loans. Our findings highlight the heightened financial vulnerability of low-income households to environmental shocks and underscore the need for targeted policies.
description: Cette étude explore l’incidence de l’exposition aux événements météorologiques extrêmes sur la situation financière des ménages à faible revenu. À partir d’un nouvel ensemble de données sur les demandes individuelles de prêts sur salaire et sur les prêts, nous constatons que les journées de chaleur ou de froid extrême entraînent une montée soudaine des demandes de prêts sur salaire. Une hausse du nombre de journées de chaleur extrême cause une augmentation du taux de défaillance et de défaut, et une réduction du crédit total octroyé, ce qui indique une contraction de l’offre de crédit. Ces effets sont particulièrement évidents pour les prêts sur salaire en ligne. Nos résultats mettent en évidence la vulnérabilité financière accrue des ménages à faible revenu aux chocs environnementaux et la nécessité d’élaborer des politiques ciblées.
Electron-phonon coupling and electronic thermoelectric properties of n-type PbTe driven near the soft-mode phase transition via lattice expansion
Creators: name: Cao, Jiang
name: Dangić, Đorđe
name: Querales-Flores, José D.
name: Fahy, Stephen
name: Savić, Ivana
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: IV-VI materials are some of the most efficient bulk thermoelectric materials due to their proximity to soft-mode phase transitions, which leads to low lattice thermal conductivity. It has been shown that the lattice thermal conductivity of PbTe can be considerably reduced by bringing PbTe closer to the phase transition e.g. via lattice expansion. However, the effect of soft phonon modes on the electronic thermoelectric properties of such system remains unknown. Using first principles calculations, we show that the soft zone center transverse optical phonons do not deteriorate the electronic thermoelectric properties of PbTe driven closer to the phase transition via lattice expansion due to external stress, and thus enhance the thermoelectric figure of merit. We find that the optical deformation potentials change very weakly as the proximity to the phase transition increases, but the population and scattering phase space of soft phonon modes increase. Nevertheless, scattering between electronic states near the band edge and soft optical phonons remains relatively weak even very near the phase transition.
description: 8 pages, 7 figures
title: Modelling Canadian mortgage debt and payments in a semi-structural model
Creators: name: Bounajm, Fares
name: McWhirter, Austin
Publisher: name: Bank of Canada
Year: 2024

description: We show how Canadian mortgage debt dynamics can be modelled in a semi-structural macroeconomic model, such as the Bank of Canada’s LENS. The model we propose accounts for Canada’s unique mortgage debt structure.
description: Nous montrons comment la dynamique de la dette hypothécaire canadienne peut être modélisée dans un modèle macroéconomique semi-structurel comme LENS utilisé par la Banque du Canada. Notre modèle reproduit la structure singulière de la dette hypothécaire canadienne.
Using Social Robots to Teach Language Skills to Immigrant Children in an Oslo City District
Creators: name: Schulz, Trenton
name: Halbach, Till
name: Solheim, Ivar
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Social robots have been shown to help in language education for children. This can be good aid for immigrant children that need additional help to learn a second language their parents do not understand to attend school. We present the setup for a long-term study that is being carried out in blinded to aid immigrant children with poor skills in the Norwegian language to improve their vocabulary. This includes additional tools to help parents follow along and provide additional help at home.
description: 3 pages, 1 figure
Direct diagonalization of Fock space for an exact solution of pairing model
Creators: name: Wang, An Min
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the exact solution of BCS pairing model using direct diagonalization of Fock space. By the data analysis and numerical calculation, we verify the symmetry between energy spectrum of Fock subspaces, obtain the common structure features of energy gaps and energy bands in Hamiltonian spectrum of reduced model, propose the formula to estimate the lowest energy levels in all of the subspaces of reduced model, and suggest a scheme to estimate the respective energy spectrum which can reveal the structure of energy spectrum of pairing model.
description: 6 pages, 4 figures. The published version
Kajkwakhrattxi orthography workshop
Creators: name: Kajkwakhrattxi, Mej
name: Kajkwakhrattxi, Nokêrê
name: Kajkwakhrattxi, Orengô
name: Kajkwakhrattxi, Rowthyktxi
name: Beauchamp, Jérémie
name: Lapierre, Myriam
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: Kajkwakhrattxi language

description: Workshop on Kajkwakhrattxi orthography held between all of the Kajkwakhrattxi school teachers, as well as Myriam Lapierre and Jérémie Beauchamp.
Optimized finite-build stellarator coils using automatic differentiation
Creators: name: McGreivy, Nick
name: Hudson, Stuart R.
name: Zhu, Caoxiang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A new stellarator coil design code is introduced that optimizes the position and winding pack orientation of finite-build coils. The new code, called FOCUSADD, performs gradient-based optimization in a high-dimensional, non-convex space. The derivatives with respect to parameters of finite-build coils are easily and efficiently computed using automatic differentiation. FOCUSADD parametrizes coil positions in free space using a Fourier series and uses a multi-filament approximation to the coil winding pack. The orientation of the winding pack is parametrized with a Fourier series and can be optimized as well. Optimized finite-build coils for a W7-X-like stellarator are found, and compared with filamentary coil results. The final positions of optimized finite-build W7-X-like coils are shifted, on average, by approximately 2.5mm relative to optimized filamentary coils. These results suggest that finite-build effects should be accounted for in the optimization of stellarators with low coil tolerances.
Period Changes in Ultra-compact Double White Dwarfs
Creators: name: Marsh, T. R.
name: Nelemans, G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In recent years there has been much interest in the nature of two stars, V407 Vul and RXJ0806+1527, which are widely thought to be binary white dwarfs of very short orbital period, 570 and 321 seconds respectively. As such they should be strong sources of gravitational waves and possible ancestors of the accreting AM CVn stars. Monitoring at X-ray and optical wavelengths has established that the period of each star is decreasing, at rates compatible with that expected from gravitational radiation. This has been taken to support the ``unipolar inductor'' model in which the white dwarfs are detached and the X-rays produced by the dissipation of magnetically-induced electric currents. In this paper we show that this interpretation is incorrect because it ignores associated torques which transfer angular momentum between the spin of the magnetic white dwarf and the orbit. We show that this torque is 10^5 times larger than the GR term in the case of V407 Vul, and 10 times larger for RXJ0806+1527. For V407 Vul, the unipolar inductor model can only survive if the white dwarf spins 100 times faster than the orbit. Since this could only come about through accretion, the validity of the unipolar inductor appears questionable for this star. We also consider whether accretion models can fit the observed spin-up, concluding that they can, provided that a mechanism exists for driving the mass transfer rate away from its equilibrium value.
description: 6 pages, 1 figure, accepted for publication in MNRAS
Study of $B^{-} \to D_{2}^{*}(2460)^{0} π^{-}$ and $B^{-} \to D_{1}(2420)^{0} π^{-} $ Decays
Creators: name: Eschenburg, Vance O.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report on a study of $B$ mesons decaying into one of the narrow P-wave charm resonances, $D_2^{*}(2460)^{0}$ and $D_1(2420)^0$. Our preliminary results are based on 89 million \BB pairs collected with the \babar detector at the PEP-II asymmetric $B$ Factory. Our study will be useful in the investigation of the properties of Heavy Quark Effective Theory.
description: 4 pages, 3 Figures. DPF 2004 Conference Paper. Submitted to International Journal of Modern Physics A. Updated to correct minor latex formatting errors
A quantum optics approach to photoinduced electron transfer in cavities
Creators: name: Wellnitz, David
name: Pupillo, Guido
name: Schachenmayer, Johannes
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We study a simple model for photoinduced electron transfer reactions for the case of many donor-acceptor pairs that are collectively and homogeneously coupled to a photon mode of a cavity. We describe both coherent and dissipative collective effects resulting from this coupling within the framework of a quantum optics Lindblad master equation. We introduce a method to derive an effective rate equation for electron transfer, by adiabatically eliminating donor and acceptor states and the cavity mode. The resulting rate equation is valid both for weak and strong coupling to the cavity mode, and describes electronic transfer through both the cavity coupled bright states and the uncoupled dark states. We derive an analytic expression for the instantaneous electron transfer rate that depends non-trivially on the time-varying number of pairs in the ground state. We find that under proper resonance conditions, and in the presence of an incoherent drive, reaction rates can be enhanced by the cavity. This enhancement persists, and can even be largest, in the weak light-matter coupling regime. We discuss how the cavity effect is relevant for realistic experiments.
description: 17 pages, 5 figures
Thermoelectric cooling properties of a quantum Hall Corbino device
Creators: name: Mateos, Juan Herrera
name: Real, Mariano A.
name: Reichl, Christian
name: Tonina, Alejandra
name: Wegscheider, Werner
name: Dietsche, Werner
name: Arrachea, Liliana
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We analyze the thermoelectric cooling properties of a Corbino device in the quantum Hall regime on the basis of experimental data of electrical conductance. We focus on the cooling power and the coefficient of performance within and beyond linear response. Thermovoltage measurements in this device reported in {\em Phys. Rev. Applied, {\bf 14} 034019 (2020)} indicated that the transport takes place in the diffusive regime, without signatures of effects due to the electron-phonon interaction in a wide range of temperatures and filling factors. In this regime, the heat and charge currents by electrons can be described by a single transmission function. We infer this function from experimental data of conductance measurements and we calculate the cooling power and the coefficient of performance for a wide range of filling factors and temperatures, as functions of the thermal and electrical biases. We predict an interesting cooling performance in several parameter regimes.
description: 10 pages, 8 figures
Salmon Recovery in the Pacific Northwest: A Summary of Agricultural and other Economic Effects
Creators: name: Aillery, Marcel P.
name: Bertels, Paul
name: Cooper, Joseph C.
name: Moore, Michael R.
name: Vogel, Stephen J.
name: Weinberg, Marca
name: Aillery, Marcel P.
name: Bertels, Paul
name: Cooper, Joseph C.
name: Moore, Michael R.
name: Vogel, Stephen J.
name: Weinberg, Marca
Publisher: name: Unknown
Year: 1994
Subjects: subject: Agricultural and Food Policy
subject: Crop Production/Industries
subject: Financial Economics
subject: Labor and Human Capital
subject: Research Methods/ Statistical Methods
subject: Salmon
subject: Endangered Species Act
subject: recovery measures
subject: Pacific Northwest
subject: Columbia River Basin
subject: agricultural sector
subject: secondary economic effects
subject: economic benefits
subject: commercial and recreational fishing

description: Measures that will be taken in the Pacific Northwest to recover three Snake River wild salmon runs protected under the Endangered Species Act--and to improve the Columbia River Basin salmon fishery as a whole--will result in various benefits and costs to the Northwest economy. This report, which describes the principal findings of a larger USDA study, analyzes the effect of Snake River management alternatives on agricultural production, profit, and resource use in the Northwest. Measures examined include reservoir drawdown along the Lower Snake River and irrigation water supply reductions in the Upper Snake River Basin. For the Northwest region, adjustments in agricultural crop production cause producer profit to decrease by less than $10 million per year (less than 1 percent in baseline profit) under five of the seven scenarios. Two scenarios would reduce profit $30-$35 million per year (2-3 percent of baseline). This report also examines secondary impacts on regional income and employment that result from the adjustments in agricultural production. Agricultural employment could decrease by 50-2,600 jobs, depending on the scenario, while total employment could decrease by 600-5,500 jobs. Finally, this report discusses selected economic benefits of salmon recovery, including improvements in commercial and sportfishing.
Average scattering entropy of quantum graphs
Creators: name: Silva, Alison A.
name: Andrade, Fabiano M.
name: Bazeia, Dionisio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The scattering amplitude in simple quantum graphs is a well-known process which may be highly complex. In this work, motivated by the Shannon entropy, we propose a methodology that associates to a graph a scattering entropy, which we call the average scattering entropy. It is defined by taking into account the period of the scattering amplitude which we calculate using the Green's function procedure. We first describe the methodology on general grounds, and then exemplify our findings considering several distinct groups of graphs. We go on and investigate other possibilities, one that contains groups of graphs with the same number of vertices, with the same degree, and the same number of edges, with the same length, but with distinct topologies and with different entropies. And the other, which contains graphs of the fishbone type, where the scattering entropy depends on the boundary conditions on the vertices of degree $1$, with the corresponding values decreasing and saturating very rapidly, as we increase the number of elementary structures in the graphs.
description: 9 pages, 12 figures, matches published version
Comment on "Strong dependence of the interlayer coupling on the hole mobility in antiferromagnetic La$_{2-x}$Sr$_x$CuO$_4$ ($x<0.02$)"
Creators: name: Korenblit, I. Ya.
name: Aharony, A.
name: Entin-Wohlman, O.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using the experimental data given in Phys. Rev. B70, 220507 (2004), we show that -- unlike the effective coupling discussed in this paper -- the net average antiferromagnetic interlayer coupling in doped lanthanum cuprates depends only weakly on the doping or on the temperature. We argue that the effective coupling is proportional to the square of the staggered magnetization, and does not supply new information about the origin of the suppression of the magnetic order in doped samples. Our analysis is based on a modified version of the equation describing the spin-flip transition, which takes into account the decrease of the staggered moment with temperature and doping.
description: Phys. Rev. B (in press)
Exploring twisted mass Lattice QCD with the Clover term
Creators: name: Becirevic, D.
name: Boucaud, Ph.
name: Lubicz, V.
name: Martinelli, G.
name: Mescia, F.
name: Simula, S.
name: Tarantino, C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: It has been shown that in the twisted mass formulation of Lattice QCD at maximal twist large cutoff effects are generated when the quark mass becomes of O(a Lambda_QCD^2). In general, these effects can be suppressed in two ways: either by choosing the critical quark mass in an "optimal way", or by adding the Clover term to the twisted action. We investigate the second option by performing a quenched lattice QCD simulation with twisted Clover fermions and pion masses as low as 280 MeV. We show that the Clover term is indeed efficient in reducing the large cutoff effects. In particular, the so-called bending phenomenon observed in the determination of the pion decay constant is cured in this way. In addition, by using maximally twisted Clover fermions, we provide a non-perturbative determination of the vector current renormalization constant Z_V as well as of the non-perturbatively renormalized light quark masses. Finally, we calculate the connected contribution to the charged-neutral pseudoscalar meson mass splitting, finding that the introduction of the Clover term in the twisted action is also beneficial, in the quenched approximation, in reducing cutoff effects related to the isospin symmetry breaking at finite lattice spacing.
description: 18 pages, 5 figures
Naturalness of exponential cosmon potentials and the cosmological constant problem
Creators: name: Wetterich, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss the naturalness of exponential potentials for quintessence, showing that the resulting almost flat direction in the space of scalar fields, as well as the small time dependent cosmon mass, can be related to an anomalous dilatation symmetry. We argue that the physics of the cosmological constant is Planck scale physics, and comment on the role of quantum fluctuations. We present three higher dimensional scenarios how a runaway of the ``cosmological constant'' to zero can be combined with stable particle physics properties, leading at most to small variations of the ``fundamental couplings''.
description: 19 pages
Sprays and Connections on the Tangent Bundle of Order Two
Creators: name: Youssef, Nabil L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C60, 53C05

description: Adopting the global approach to tangent bundles of order two established in[1], we develop this approach to find new results. We also generalize various results of [3], [4] and [6] to the geometry of tangent bundles of order two.
description: 15 pages,laTeX file
A Pyramidal Evolutionary Algorithm with Different Inter-Agent Partnering Strategies for Scheduling Problems
Creators: name: Aickelin, Uwe
Publisher: name: arXiv
Year: 2008
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: This paper combines the idea of a hierarchical distributed genetic algorithm with different inter-agent partnering strategies. Cascading clusters of sub-populations are built from bottom up, with higher-level sub-populations optimising larger parts of the problem. Hence higher-level sub-populations search a larger search space with a lower resolution whilst lower-level sub-populations search a smaller search space with a higher resolution. The effects of different partner selection schemes amongst the agents on solution quality are examined for two multiple-choice optimisation problems. It is shown that partnering strategies that exploit problem-specific knowledge are superior and can counter inappropriate (sub-) fitness measurements.
Viscous FRW Cosmology in Modified Gravity
Creators: name: Brevik, I.
name: Gorbunova, O.
name: Shaido, Y. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss a modified form of gravity implying that the action contains a power αof the scalar curvature. Coupling with the cosmic fluid is assumed. As equation of state for the fluid, we take the simplest version where the pressure is proportional to the density. Based upon a natural ansatz for the time variation of the scale factor, we show that the equations of motion are satisfied for general α. Also the condition of conservation of energy and momentum is satisfied. Moreover, we investigate the case where the fluid is allowed to possess a bulk viscosity, and find the noteworthy fact that consistency of the formalism requires the bulk viscosity to be proportional to the power (2α-1) of the scalar expansion. In Einstein's gravity, where α=1, this means that the bulk viscosity is proportional to the scalar expansion. This mathematical result is of physical interest; as discussed recently by the present authors, there exists in principle a viscosity-driven transition of the fluid from the quintessence region into the phantom region, implying a future Big Rip singularity.
description: 8 pages, no figures
Magnon Thermal Edelstein Effect Detected by Inverse Spin Hall Effect
Creators: name: Zhang, Hantao
name: Cheng, Ran
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In an easy-plane antiferromagnet with the Dzyaloshinskii-Moriya interaction (DMI), magnons are subject to an effective spin-momentum locking. An in-plane temperature gradient can generate interfacial accumulation of magnons with a specified polarization, realizing the magnon thermal Edelstein effect. We theoretically investigate the injection and detection of this thermally-driven spin polarization in an adjacent heavy metal with strong spin Hall effect. We find that the inverse spin Hall voltage depends monotonically on both temperature and the DMI but non-monotonically on the hard-axis anisotropy. Counterintuitively, the magnon thermal Edelstein effect is an even function of a magnetic field applied along the Néel vector.
A multiplicative comparison of MacLane homology and topological Hochschild homology
Creators: name: Horel, Geoffroy
name: Ramzi, Maxime
Publisher: name: arXiv
Year: 2020
Subjects: subject: Algebraic Topology (math.AT)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics

description: Let $Q$ denote MacLane's $Q$-construction, and $\otimes$ denote the smash product of spectra. In this paper we construct an equivalence $Q(R)\simeq \mathbb Z\otimes R$ in the category of $A_\infty$ ring spectra for any ring $R$, thus proving a conjecture made by Fiedorowicz, Schwänzl, Vogt and Waldhausen in "MacLane homology and topological Hochschild homology". More precisely, we construct is a symmetric monoidal structure on $Q$ (in the $\infty$-categorical sense) extending the usual monoidal structure, for which we prove an equivalence $Q(-)\simeq \mathbb Z\otimes -$ as symmetric monoidal functors, from which the conjecture follows immediately. From this result, we obtain a new proof of the equivalence $\mathrm{HML}(R,M)\simeq \mathrm{THH}(R,M)$ originally proved by Pirashvili and Waldaushen in "MacLane homology and topological Hochschild homology" (a different paper from the one cited above). This equivalence is in fact made symmetric monoidal, and so it also provides a proof of the equivalence $\mathrm{HML}(R)\simeq \mathrm{THH}(R)$ as $E_\infty$ ring spectra, when $R$ is a commutative ring.
description: 26 pages
An Exact Construction of Codimension two Holography
Creators: name: Miao, Rong-Xin
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Recently, a codimension two holography called wedge holography is proposed as a generalization of AdS/CFT. It is conjectured that a gravitational theory in $d+1$ dimensional wedge spacetime is dual to a $d-1$ dimensional CFT on the corner of the wedge. In this paper, we give an exact construction of the gravitational solutions for wedge holography from the ones in AdS/CFT. By applying this construction, we prove the equivalence between wedge holography and AdS/CFT for vacuum Einstein gravity, by showing that the classical gravitational action and thus the CFT partition function in large N limit are the same for the two theories. The equivalence to AdS/CFT can be regarded as a "proof" of wedge holography in a certain sense. As an application of this powerful equivalence, we derive easily the holographic Weyl anomaly, holographic Entanglement/Rényi entropy and correlation functions for wedge holography. Besides, we discuss the general solutions of wedge holography and argue that they correspond to the AdS/CFT with suitable matter fields. Interestingly, we notice that the intrinsic Ricci scalar on the brane is always a constant, which depends on the tension. Finally, we generalize the discussions to dS/CFT and flat space holography. Remarkably, we find that AdS/CFT, dS/CFT and flat space holography can be unified in the framework of codimension two holography in asymptotically AdS. Different dualities are distinguished by different types of spacetimes on the brane.
description: 29 pages, 4 figures, references added, revision accepted for publication in JHEP
Non-Fermi Liquid Behavior Induced by Resonant Diquark-pair Scattering in Heated Quark Matter
Creators: name: Kitazawa, Masakiyo
name: Kunihiro, Teiji
name: Nemoto, Yukio
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We show how the quasiparticle picture of quarks changes near but above the critical temperature T_c of the color-superconducting phase transition in the heated quark matter. We demonstrate that a non-Fermi liquid behavior of the matter develops drastically when the diquark coupling constant is increased owing to the coupling of the quark with the pairing soft mode: We clarify that the depression and eventually the appearance of a gap structure in the spectral function as well as the anomalous quark dispersion relation of the quark can be understood in terms of the resonant scattering between the incident quark and a particle near the Fermi surface to make the pairing soft mode.
description: 6 pages, 10 eps figures, version to appear in Phys. Lett. B. typos corrected
The Large $N_c$ limit of QCD on the lattice
Creators: name: Hernández, Pilar
name: Romero-López, Fernando
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We review recent progress in the study of the large $N_c$ limit of gauge theories from lattice simulations. The focus is not only the planar limit but also the size of ${\mathcal O}(N_c^{-1})$ corrections for values of $N_c\gtrsim 3$. Some concrete examples of the topics we include are tests of large-$N_c$ factorization, the topological susceptibility, the glueball, meson and baryon spectra, the chiral dependence of masses and decay constants, and weak matrix elements related to the $ΔI=1/2$ rule in kaon decays.
description: Contribution to the EPJA special issue "Lattice Field Theory during the COVID-19 pandemic". 19 pages, 17 figures, 1 table. Accepted in EPJA. Minor formatting issue fixed
Discontinuous quantum and classical magnetic response of the pentakis dodecahedron
Creators: name: Konstantinidis, N. P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The pentakis dodecahedron, the dual of the truncated icosahedron, consists of 60 edge-sharing triangles. It has 20 six- and 12 five-fold coordinated vertices, with the former forming a dodecahedron, and each of the latter connected to the vertices of one of the 12 pentagons of the dodecahedron. When spins mounted on the vertices of the pentakis dodecahedron interact according to the nearest-neighbor antiferromagnetic Heisenberg model, the two different vertex types necessitate the introduction of two exchange constants. As the relative strength of the two constants is varied the molecule interpolates between the dodecahedron and a molecule consisting only of quadrangles. The competition between the two exchange constants, frustration, and an external magnetic field results in a multitude of ground-state magnetization and susceptibility discontinuities. At the classical level the maximum is ten magnetization and one susceptibility discontinuities when the 12 five-fold vertices interact with the dodecahedron spins with approximately one-half the strength of their interaction. When the two interactions are approximately equal in strength the number of discontinuities is also maximized, with three of the magnetization and eight of the susceptibility. At the full quantum limit, where the magnitude of the spins equals 1/2, there can be up to three ground-state magnetization jumps that have the total z spin component changing by ΔS^z=2, even though quantum fluctuations rarely allow discontinuities of the magnetization. The full quantum case also supports a ΔS^z=3 discontinuity. Frustration also results in nonmagnetic states inside the singlet-triplet gap. These results make the pentakis dodecahedron the molecule with the most discontinuous magnetic response from the quantum to the classical level.
description: 24 pages, 16 figures, 4 tables
How large is the spreading width of a superdeformed band?
Creators: name: Wilson, A. N.
name: Sargeant, A. J.
name: Davidson, P. M.
name: Hussein, M. S
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Recent models of the decay out of superdeformed bands can broadly be divided into two categories. One approach is based on the similarity between the tunneling process involved in the decay and that involved in the fusion of heavy ions, and builds on the formalism of nuclear reaction theory. The other arises from an analogy between the superdeformed decay and transport between coupled quantum dots. These models suggest conflicting values for the spreading width of the decaying superdeformed states. In this paper, the decay of superdeformed bands in the five even-even nuclei in which the SD excitation energies have been determined experimentally is considered in the framework of both approaches, and the significance of the difference in the resulting spreading widths is considered. The results of the two models are also compared to tunneling widths estimated from previous barrier height predictions and a parabolic approximation to the barrier shape.