cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Scaling from gauge and scalar radiation in Abelian Higgs string networks
Creators: name: Hindmarsh, Mark
name: Lizarraga, Joanes
name: Urrestilla, Jon
name: Daverio, David
name: Kunz, Martin
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate cosmic string networks in the Abelian Higgs model using data from a campaign of large-scale numerical simulations on lattices of up to $4096^3$ grid points. We observe scaling or self-similarity of the networks over a wide range of scales, and estimate the asymptotic values of the mean string separation in horizon length units $\dotξ$ and of the mean square string velocity $\bar v^2$ in the continuum and large time limits. The scaling occurs because the strings lose energy into classical radiation of the scalar and gauge fields of the Abelian Higgs model. We quantify the energy loss with a dimensionless radiative efficiency parameter, and show that it does not vary significantly with lattice spacing or string separation. This implies that the radiative energy loss underlying the scaling behaviour is not a lattice artefact, and justifies the extrapolation of measured network properties to large times for computations of cosmological perturbations. We also show that the core growth method, which increases the defect core width with time to extend the dynamic range of simulations, does not introduce significant systematic error. We compare $\dotξ$ and $\bar v^2$ to values measured in simulations using the Nambu-Goto approximation, finding that the latter underestimate the mean string separation by about 25%, and overestimate $\bar v^2$ by about 10%. The scaling of the string separation implies that string loops decay by the emission of massive radiation within a Hubble time in field theory simulations, in contrast to the Nambu-Goto scenario which neglects this energy loss mechanism. String loops surviving for only one Hubble time emit much less gravitational radiation than in the Nambu-Goto scenario, and are consequently subject to much weaker gravitational wave constraints on their tension.
description: 19 pages, 12 figures. v2: typos fixed and video link added https://vimeo.com/214671412 . v3: minor changes, matches published version
Thermodynamic and Holographic Information Dual to Volume
Creators: name: Momeni, Davood
name: Faizal, Mir
name: Alsaleh, Salwa
name: Alasfar, Lina
name: Myrzakul, Aizhan
name: Myrzakulov, Ratbay
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we will analyze the connection between the fidelity susceptibility, the holographic complexity and the thermodynamic volume. We will regularize the fidelity susceptibility and the holographic complexity by subtracting the contribution of the background AdS spacetime from the deformation of the AdS spacetime. It will be demonstrated that this regularized fidelity susceptibility has the same behavior as the thermodynamic volume and that the regularized complexity has a very different behavior. As the information dual to different volumes in the bulk would be measured by the fidelity susceptibility and the holographic complexity, this paper will establish a connection between thermodynamics and information dual to a volume.
description: Accepted in the "European Physical Journal C", minor changes, two figures deleted,
Conformal Bootstrap in the Regge Limit
Creators: name: Li, Daliang
name: Meltzer, David
name: Poland, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We analytically solve the conformal bootstrap equations in the Regge limit for large N conformal field theories. For theories with a parametrically large gap, the amplitude is dominated by spin-2 exchanges and we show how the crossing equations naturally lead to the construction of AdS exchange Witten diagrams. We also show how this is encoded in the anomalous dimensions of double-trace operators of large spin and large twist. We use the chaos bound to prove that the anomalous dimensions are negative. Extending these results to correlators containing two scalars and two conserved currents, we show how to reproduce the CEMZ constraint that the three-point function between two currents and one stress tensor only contains the structure given by Einstein-Maxwell theory in AdS, up to small corrections. Finally, we consider the case where operators of unbounded spin contribute to the Regge amplitude, whose net effect is captured by summing the leading Regge trajectory. We compute the resulting anomalous dimensions and corrections to OPE coefficients in the crossed channel and use the chaos bound to show that both are negative.
description: 40 pages, 1 figure; V2: Small corrections and clarifications
Photometric classification and redshift estimation of LSST Supernovae
Creators: name: Dai, Mi
name: Kuhlmann, Steve
name: Wang, Yun
name: Kovacs, Eve
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Supernova (SN) classification and redshift estimation using photometric data only have become very important for the Large Synoptic Survey Telescope (LSST), given the large number of SNe that LSST will observe and the impossibility of spectroscopically following up all the SNe. We investigate the performance of a SN classifier that uses SN colors to classify LSST SNe with the Random Forest classification algorithm. Our classifier results in an AUC of 0.98 which represents excellent classification. We are able to obtain a photometric SN sample containing 99$\%$ SNe Ia by choosing a probability threshold. We estimate the photometric redshifts (photo-z) of SNe in our sample by fitting the SN light curves using the SALT2 model with nested sampling. We obtain a mean bias ($\left$) of 0.012 with $σ\left( \frac{z_\mathrm{phot}-z_\mathrm{spec}}{1+z_\mathrm{spec}}\right) = 0.0294$ without using a host-galaxy photo-z prior, and a mean bias ($\left$) of 0.0017 with $σ\left( \frac{z_\mathrm{phot}-z_\mathrm{spec}}{1+z_\mathrm{spec}}\right) = 0.0116$ using a host-galaxy photo-z prior. Assuming a flat $ΛCDM$ model with $Ω_m=0.3$, we obtain $Ω_m$ of $0.305\pm0.008$ (statistical errors only), using the simulated LSST sample of photometric SNe Ia (with intrinsic scatter $σ_\mathrm{int}=0.11$) derived using our methodology without using host-galaxy photo-z prior. Our method will help boost the power of SNe from the LSST as cosmological probes.
description: 12 pages, 8 figures, 5 tables, accepted for publication in MNRAS
Measurement of Hubble constant with stellar-mass binary black holes
Creators: name: Nishizawa, Atsushi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The direct detections of gravitational waves (GW) from merging binary black holes (BBH) by aLIGO have brought us a new opportunity to utilize BBH for a measurement of the Hubble constant. In this paper, we point out that there exists a small number of BBH that gives significantly small sky localization volume so that a host galaxy is uniquely identified. Then a redshift of a BBH is obtained from a spectroscopic follow-up observation of the host galaxy. Using these redshift-identified BBH, we show that the Hubble constant is measured at a level of precision better than 1% with advanced detectors like aLIGO at design sensitivity. Since a GW observation is completely independent of other astrophysical means, this qualitatively new probe will help resolve a well-known value discrepancy problem on the Hubble constant from cosmological measurements and local measurements.
description: 7 pages, 4 figures, accepted as a Rapid Communication in Physical Review D
Generalized two-field $α$-attractor models from geometrically finite hyperbolic surfaces
Creators: name: Lazaroiu, C. I.
name: Shahbazi, C. S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider four-dimensional gravity coupled to a non-linear sigma model whose scalar manifold is a non-compact geometrically finite surface $Σ$ endowed with a Riemannian metric of constant negative curvature. When the space-time is an FLRW universe, such theories produce a very wide generalization of two-field $α$-attractor models, being parameterized by a positive constant $α$, by the choice of a finitely-generated surface group $Γ\subset \mathrm{PSL}(2,\mathbb{R})$ (which is isomorphic with the fundamental group of $Σ$) and by the choice of a scalar potential defined on $Σ$. The traditional two-field $α$-attractor models arise when $Γ$ is the trivial group, in which case $Σ$ is the Poincaré disk. We give a general prescription for the study of such models through uniformization in the so-called "non-elementary" case and discuss some of their qualitative features in the gradient flow approximation, which we relate to Morse theory. We also discuss some aspects of the SRST approximation in these models, showing that it is generally not well-suited for studying dynamics near cusp ends. When $Σ$ is non-compact and the scalar potential is "well-behaved" at the ends, we show that, in the {\em naive} local one-field truncation, our generalized models have the same universal behavior as ordinary one-field $α$-attractors if inflation happens near any of the ends of $Σ$ where the extended potential has a local maximum, for trajectories which are well approximated by non-canonically parameterized geodesics near the ends, we also discuss spiral trajectories near the ends.
description: 60 pages
Constraining the mass of light bosonic dark matter using SDSS Lyman-$α$ forest
Creators: name: Armengaud, Eric
name: Palanque-Delabrouille, Nathalie
name: Yèche, Christophe
name: Marsh, David J. E.
name: Baur, Julien
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: If a significant fraction of the dark matter in the Universe is made of an ultra-light scalar field, named fuzzy dark matter (FDM) with a mass $m_a$ of the order of $10^{-22}-10^{-21}$ eV, then its de Broglie wavelength is large enough to impact the physics of large scale structure formation. In particular, the associated cut-off in the linear matter power spectrum modifies the structure of the intergalactic medium (IGM) at the scales probed by the Lyman-$α$ forest of distant quasars. We study this effect by making use of dedicated cosmological simulations which take into account the hydrodynamics of the IGM. We explore heuristically the amplitude of quantum pressure for the FDM masses considered here and conclude that quantum effects should not modify significantly the non-linear evolution of matter density at the scales relevant to the measured Lyman-$α$ flux power, and for $m_a \geq 10^{-22}$ eV. We derive a scaling law between $m_a$ and the mass of the well-studied thermal warm dark matter (WDM) model that is best adapted to the Lyman-$α$ forest data, and differs significantly from the one infered by a simple linear extrapolation. By comparing FDM simulations with the Lyman-$α$ flux power spectra determined from the BOSS survey, and marginalizing over relevant nuisance parameters, we exclude FDM masses in the range $10^{-22} \leq m_a < 2.3\times 10^{-21}$ eV at 95 % CL. Adding higher-resolution Lyman-$α$ spectra extends the exclusion range up to $2.9\times 10^{-21}$ eV. This provides a significant constraint on FDM models tailored to solve the "small-scale problems" of $Λ$CDM.
description: Matches accepted version
title: Max Weber in the tropics: How global climate politics facilitates the bureaucratization of forestry in Indonesia
Creators: name: Lederer, Markus
name: Höhne, Chris
Publisher: name: John Wiley & Sons
Year: 2024

description: Reducing Emissions from Deforestation and Forest Degradation (REDD+) is one of the most advanced global climate governance arrangements and we show that it contributes to the buildup of autonomous capacities and reliable procedures in areas of rather limited statehood. These partially unintended effects can be conceptualized as an increasing rational–legal bureaucratization, which has been initiated through both external and domestic actors as we illuminate in the case of Indonesia's forestry sector in the period from 2007 until 2017. Our finding is that a bureaucratization of a new kind is increasingly strengthened in Indonesia's forest despite enduring patterns of neopatrimonialism, emerging signs of new public management approaches, and the strengthening of functional equivalents such as community‐based forest management. We thus claim that Max Weber's perspective on the prospects and problems of rational–legal bureaucratization is still valuable, even when travelling to the tropics.
The impact of COVID-19 on relationships between family/friend caregivers and care staff in continuing care facilities: a qualitative descriptive analysis
Creators: name: Beeber, Anna
name: Hoben, Matthias
name: Dymchuk, Emily
name: Mirhashemi, Bita
name: Chamberlain, Stephanie
Publisher: name: Springer Nature
Year: 2023

description:
Background The COVID-19 pandemic and related public health measures added a new dynamic to the relationship between caregivers and care staff in congregate care settings. While both caregivers and staff play an important role in resident quality of life and care, it is common for conflict to exist between them. These issues were amplified by pandemic restrictions, impacting not only caregivers and care staff, but also residents. While research has explored the relationship between caregivers and care staff in long-term care and assisted living homes, much of the research has focused on the caregiver perspective. Our objective was to explore the impact of COVID-19-related public health measures on caregiver-staff relationships from the perspective of staff in long-term care and assisted living homes. Methods We conducted 9 focus groups and 2 semi-structured interviews via videoconference. Results We identified four themes related to caregiver-staff relationships: (1) pressure from caregivers, (2) caregiver-staff conflict, (3) support from caregivers, and (4) staff supporting caregivers. Conclusions The COVID-19 pandemic disrupted long-standing relationships between caregivers and care staff, negatively impacting care staff, caregivers, and residents. However, staff also reported encouraging examples of successful collaboration and support from caregivers. Learning from these promising practices will be critical to improving preparedness for future public health crises, as well as quality of resident care and life in general.
New method of computing the contributions of graphs without lepton loops to the electron anomalous magnetic moment in QED
Creators: name: Volkov, Sergey
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: This paper presents a new method of numerical computation of the QED contributions to the electron anomalous magnetic moment which arises from Feynman graphs containing electron and photon lines and not containing electron loops. The method consists of two parts. The first part is the forest-like subtraction formula that removes all ultraviolet and infrared divergences in each Feynman graph point-by-point in Feynman-parametric space. The second part is the importance sampling Monte-Carlo algorithm with the probability density function that is constructed for each Feynman graph individually. The method is fully automated at any order of the perturbation series. The results of applying the method to 2-loop, 3-loop, 4-loop Feynman graphs and to some individual 5-loop graphs are presented.
Periodic squeezing in a polariton Josephson junction
Creators: name: Adiyatullin, Albert F.
name: Anderson, Mitchell D.
name: Flayac, Hugo
name: Portella-Oberli, Marcia T.
name: Jabeen, Fauzia
name: Ouellet-Plamondon, Clauderic
name: Sallen, Gregory C.
name: Deveaud, Benoit
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The use of a Kerr nonlinearity to generate squeezed light is a well-known way to surpass the quantum noise limit along a given field quadrature. Nevertheless, in the most common regime of weak nonlinearity, a single Kerr resonator is unable to provide the proper interrelation between the field amplitude and squeezing required to induce a sizable deviation from Poissonian statistics. We demonstrate experimentally that weakly coupled bosonic modes allow exploration of the interplay between squeezing and displacement, which can give rise to strong deviations from the Poissonian statistics. In particular, we report on the periodic bunching in a Josephson junction formed by two coupled exciton-polariton modes. Quantum modeling traces the bunching back to the presence of quadrature squeezing. Our results, linking the light statistics to squeezing, are a precursor to the study of nonclassical features in semiconductor microcavities and other weakly nonlinear bosonic systems.
description: 6 pages, 4 figures
Shock formation for $2D$ quasilinear wave systems featuring multiple speeds: Blowup for the fastest wave, with non-trivial interactions up to the singularity
Creators: name: Speck, Jared
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: Primary: 35L67, Secondary: 35L05, 35L52, 35L72

description: We prove a stable shock formation result for a large class of systems of quasilinear wave equations in two spatial dimensions. We give a precise description of the dynamics all the way up to the singularity. Our main theorem applies to systems of two wave equations featuring two distinct wave speeds and various quasilinear and semilinear nonlinearities, while the solutions under study are (non-symmetric) perturbations of simple outgoing plane symmetric waves. The two waves are allowed to interact all the way up to the singularity. Our approach is robust and could be used to prove shock formation results for other related systems with many unknowns and multiple speeds, in various solution regimes, and in higher spatial dimensions. However, a fundamental aspect of our framework is that it applies only to solutions in which the "fastest wave" forms a shock while the remaining solution variables do not. Our approach is based on an extended version of the geometric vectorfield method developed by D. Christodoulou in his study of shock formation for scalar wave equations as well as the framework developed in our recent joint work with J. Luk, in which we proved a shock formation result for a quasilinear wave-transport system featuring a single wave operator. A key new difficulty that we encounter is that the geometric vectorfields that we use to commute the equations are, by necessity, adapted to the wave operator of the (shock-forming) fast wave and therefore exhibit very poor commutation properties with the slow wave operator, much worse than their commutation properties with a transport operator. To overcome this difficulty, we rely on a first-order reformulation of the slow wave equation, which, though somewhat limiting in the precision it affords, allows us to avoid uncontrollable commutator terms.
description: 117 pages, 3 figures
title: Séminaire 2022 de l'OHMI Patagonia-Bahia Exploradores (17/03/2022)
Publisher: name: LabEx DRIIHM
Year: 2022

description: Ce séminaire rends compte des recherches menées dans la vallée d'Exploradores, région d'Aysén (Chili), au cours des quatre dernières années.
title: Hydrogen effects in X30MnCrN16‐14 austenitic steel
Creators: name: Michler, T.
name: Bruder, E.
name: Lindner, S.
Publisher: name: Wiley-VCH
Year: 2024

description: Chrome‐manganese‐nitrogen austenitic steels show a technically relevant combination of proprties, i. e. high strength, high ductility, non magnetic and good corrosion resistance at costs being much lower compared to conventional chrome‐nickel austenitic stainless steels which are widely used for hydrogen applications. Hydrogen environment embrittlement of steel X30MnCrN16‐14 is investigated by slow displacement rate tensile testing in hydrogen atmosphere at 10 MPa and room temperature. Compared to the values in air, the elongation at fracture as well as the reduction of area are severely reduced in the presence of hydrogen. The microstructure is characterized in detail and the deformation modes are previously reported. It is assumed that the inherent planar deformation modes are facilitated by hydrogen resulting in premature failure.
Nonlinear Perturbation of a Noisy Hamiltonian Lattice Field Model: Universality Persistence
Creators: name: Bernardin, Cédric
name: Gonçalves, Patricia
name: Jara, Milton
name: Simon, Marielle
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In [2] it has been proved that a linear Hamiltonian lattice field perturbed by a conservative stochastic noise belongs to the 3/2-Lévy/Diffusive universality class in the nonlinear fluctuating theory terminology [15], i.e. energy superdiffuses like an asymmetric stable 3/2-Lévy process and volume like a Brownian motion. According to this theory this should remain valid at zero tension if the harmonic potential is replaced by an even potential. In this work we consider a quartic anharmonicity and show that the result obtained in the harmonic case persists up to some small critical value of the anharmonicity.
Scientists call for ambitious Sustainable Use of Pesticides Regulation
Creators: name: Candel, Jeroen
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
European Union
Pesticides

description: The heavy use of chemical pesticides in agriculture is strongly linked to declines in insects, birds, biodiversity in terrestrial and aquatic systems and detrimental impacts on global public health. Given the urgent need for reduction of pesticide impacts, it is worrying to observe that a number of Member State governments and Members of the European Parliament have recently called for the delay and/or watering down of the new pesticides regulation. As members of the scientific community, we express our deep concern.
Scientists call for ambitious Sustainable Use of Pesticides Regulation
Creators: name: Candel, Jeroen
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
European Union
Pesticides

description: The heavy use of pesticides in agriculture is strongly linked to declines in insects, birds, biodiversity in terrestrial and aquatic systems and detrimental impacts on global public health. Given the urgent need for reduction of pesticide impacts, it is worrying to observe that a number of Member State governments and Members of the European Parliament have recently called for the delay and/or watering down of the new pesticides regulation. As members of the scientific community, we express our deep concern.
In vitro antioxidant activity, antidiabetic activity and in silico docking studies of 3,3′,4′,5,7-pentahydroxyflavone and stigmasta-5,22-dien-3β-ol isolated from aerial parts of Euphorbia milii. Des moul
Creators: name: A.Ch, Pradyutha
name: Yadam, Sabitha
name: Rao, V. Umamaheswara
Publisher: name: Taylor & Francis
Year: 2024
Subjects: Biochemistry
Pharmacology
Biotechnology
Chemical Sciences not elsewhere classified
Biological Sciences not elsewhere classified

description: This research focused on evaluating the in vitro antioxidant, antidiabetic activities and Insilco docking properties of two phytocompounds 3,3′,4′,5,7-Pentahydroxyflavone (Quercetin) and Stigmasta-5,22-dien-3β-ol (Stigma sterol). These compounds were isolated from the methanol extract of stem and ethanol extract of flower of the E. milii plant. The antioxidant properties of these phytocompounds were studied using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. A comparison was made between the antioxidant activity of quercetin, stigma sterol, and the standard drug ascorbic acid. The results indicated that quercetin showed significant antioxidant activity, suggesting its potential as an effective antioxidant. Additionally, in vitro antidiabetic activity was investigated through α-amylase and α-glucosidase inhibition assays. Screened compounds exhibited significant % of inhibition values against two carbohydrate hydrolysing enzymes, α-amylase and α-glucosidase compared to reference drug (acarbose). Furthermore, molecular docking studies were conducted to analyse the interaction of the compounds with α-d-glucose (PDB ID: 3A4A) and PTP1B I (PDB ID: 1T49) as target molecules. These docking studies provided further insights to support the biological findings of the compounds isolated from E. milii aerial parts.
A characterization of the Logarithmic Least Squares Method
Creators: name: Csató, László
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 90B50, 91B08

description: We provide an axiomatic characterization of the Logarithmic Least Squares Method (sometimes called row geometric mean), used for deriving a preference vector from a pairwise comparison matrix. This procedure is shown to be the only one satisfying two properties, correctness in the consistent case, which requires the reproduction of the inducing vector for any consistent matrix, and invariance to a specific transformation on a triad, that is, the weight vector is not influenced by an arbitrary multiplication of matrix elements along a 3-cycle by a positive scalar.
description: 11 pages
FEDORA materials effectiveness to develop thinking and future- scaffolding skills and to foster aware, responsible and proactive engagement with science: results and hypotheses from the second round implementations - Deliverable 4.3
Creators: name: Tasquier, Giulia
name: Barelli, Eleonora
name: LEVRINI, OLIVIA
name: Chan, Jessica
name: De Zuani Cassina, Francesco
name: Fantini, Paola
name: Hyyppä, Iina
name: Laherto, Antti
name: Rasa, Tapio
name: Satanassi, Sara
Publisher: name: Zenodo
Year: 2023
Subjects: education, sciences, futures thinking, science education

description: This document is an update of FEDORA's deliverable 4.2 that contains a report on the first-round implementations. Even if the two documents share many traits, this deliverable is not only a replica of the previous one. Indeed, the final round of implementation of teaching activities in the OSNs comes at the end of a three-year long process of theorization, implementation, and analysis that characterised the work within WP4 and in general, all FEDORA's work packages. In particular, the issues pointed out and the recommendations elaborated within the three frameworks on interdisciplinarity (FR1), new languages (FR2), and future (FR3), as well as the findings from the first round, served as the basis to orient the design of the final round of implementations in order to stress more and more explicitly their "FEDORA character".
Current driven second harmonic domain wall resonance in ferromagnetic metal/ nonmagnetic metal bilayer: a field-free method for spin Hall angle measurements
Creators: name: Hajiali, M. R.
name: Hamdi, M.
name: Roozmeh, S. E.
name: Mohseni, S. M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We study the ac current-driven domain wall motion in bilayer ferromagnetic metal (FM)/nonmagnetic metal (NM) nanowire. The solution of the modified Landau-Lifshitz-Gilbert equation including all the spin transfer torques is used to describe motion of the domain wall in presence of the spin Hall effect. We show that the domain wall center has second harmonic frequency response in addition to the known first harmonic excitation. In contrast to the experimentally observed second harmonic response in harmonic Hall measurements of spin-orbit torque in magnetic thin films, this second harmonic response directly originates from spin-orbit torque driven domain wall dynamics. Based on the spin current generated by domain wall dynamics, the longitudinal spin motive force generated voltage across the length of the nanowire is determined. The second harmonic response introduces additionally a new practical field-free and all-electrical method to probe the effective spin Hall angle for FM/NM bilayer structures that could be applied in experiments. Our results also demonstrate the capability of utilizing FM/NM bilayer structure in domain wall based spin torque signal generators and resonators.
description: M. R. Hajiali and M. Hamdi contributed equally to this work
A Group of Immersed Finite Element Spaces For Elliptic Interface Problems
Creators: name: Guo, Ruchi
name: Lin, Tao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present a unified framework for developing and analysing immersed finite element (IFE) spaces for solving typical elliptic interface problems with interface independent meshes. This framework allows us to construct a group of new IFE spaces with either linear, or bilinear, or the rotated-Q1 polynomials. Functions in these IFE spaces are locally piecewise polynomials defined according to the sub-elements formed by the interface itself instead of its line approximation. We show that the unisolvence for these IFE spaces follows from the invertibility of the Sherman-Morrison matrix. A group of estimates and identities are established for the interface geometry and shape functions that are applicable to all of these IFE spaces. Most importantly, these fundamental preparations enable us to develop a unified multipoint Taylor expansion procedure for proving that these IFE spaces have the expected optimal approximation capability according to the involved polynomials.
description: 27 pages, 3 figures
Lay theories about emotion recognition explain cultural differences in willingness to wear facial masks during the COVID-19 pandemic
Creators: name: Nayani, Fatima Z
name: Yuki, Masaki
name: Maddux, William W
name: Schug, Joanna
Publisher: name: Elsevier
Year: 2023

description:
Given that mask-wearing proved to be an important tool to slow the spread of infection during the COVID-19 pandemic, investigating the psychological and cultural factors that influence norms for mask wearing across cultures is exceptionally important. One factor that may influence mask wearing behavior is the degree to which people believe masks potentially impair emotion recognition. Based on previous research suggesting that there may be cultural differences in facial regions that people in Japan and the United States attend to when inferring a target's emotional state, we predicted that Americans would perceive masks (which cover the mouth) as more likely to impair emotion recognition, whereas Japanese would perceive facial coverings that conceal the eye region (sunglasses) to be more likely to impair emotion recognition. The results showed that Japanese participants reported wearing masks more than Americans. Americans also reported higher expected difficulty in interpreting emotions of individuals wearing masks (vs. sunglasses), while Japanese reported the reverse effect. Importantly, expectations about the negative impact of facial masks on emotion recognition explained cultural differences in mask-wearing behavior, even accounting for existing social norms.
title: Stable and Active Oxygen Reduction Catalysts with Reduced Noble Metal Loadings through Potential Triggered Support Passivation
Creators: name: Göhl, Daniel
name: Rueß, Holger
name: Schlicht, Stefanie
name: Vogel, Alexandra
name: Rohwerder, Michael
name: Mayrhofer, Karl J. J.
name: Bachmann, Julien
name: Román‐Leshkov, Yuriy
name: Schneider, Jochen M.
name: Ledendecker, Marc
Publisher: name: Wiley-VCH
Year: 2024

description: The development of stable, cost‐efficient and active materials is one of the main challenges in catalysis. The utilization of platinum in the electroreduction of oxygen is a salient example where the development of new material combinations has led to a drastic increase in specific activity compared to bare platinum. These material classes comprise nanostructured thin films, platinum alloys, shape‐controlled nanostructures and core–shell architectures. Excessive platinum substitution, however, leads to structural and catalytic instabilities. Herein, we introduce a catalyst concept that comprises the use of an atomically thin platinum film deposited on a potential‐triggered passivating support. The model catalyst exhibits an equal specific activity with higher atom utilization compared to bulk platinum. By using potential‐triggered passivation of titanium carbide, irregularities in the Pt film heal out via the formation of insoluble oxide species at the solid/liquid interface. The adaptation of the described catalyst design to the nanoscale and to high‐surface‐area structures highlight the potential for stable, passivating catalyst systems for various electrocatalytic reactions such as the oxygen reduction reaction.
Dark Matter Search in Space: Combined Analysis of Cosmic Ray Antiproton-to-Proton Flux Ratio and Positron Flux Measured by AMS-02
Creators: name: Feng, Jie
name: Zhang, Hong-Hao
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Dark matter search in space has been carried out for many years. Measurements of cosmic ray photons, charged antiparticles and neutrinos are useful tools for dark matter indirect search. The antiparticle energy spectra of cosmic rays have several exciting features such as the unexpected positron excess at energy about 10 -- 500 GeV and the remarkably flattening antiproton/proton at energy about 60--450 GeV precisely measured by the AMS-02 experiment, which can not be explained simultaneously by secondary production in interstellar medium. In this work, we report a combined analysis of cosmic ray antiproton and positron spectra arising from dark matter on the top of a secondary production in a spatial-dependent propagation model. We discuss the systematics from antiproton production cross section using the two latest Monte Carlo generators, i.e. EPOS LHC and QGSJET-II-04m, respectively. We compare their results. In the case of EPOS LHC, we find that the dark matter pair annihilating into tau leptons channel with 100% branching ratio is the only possible one channel scenario to explain data. On the other hand, there is not a single possible channel in the case of QGSJET-II-04m. We also propose possible two-channel scenarios based on these two Monte Carlo generators.
description: 10 pages, 7 figures, 2 table, accepted for publication in the ApJ
Transport, EURAD Domain Insight
Creators: name: Holt, Erika
name: Suolanen, Vesa
Publisher: name: Zenodo
Year: 2022
Subjects: cask
inspection
package
predisposal
radiation protection
safety
security
transport

description: The roadmap describes typical programme goals, activities and capabilities needed against 7 themes, which are each further broken down into sub-themes and domains in what we can call the Goals Breakdown Structure (GBS). This document provides the overall goal for the Transport domain (Transport radioactive wastes between facilities in accordance with regulatory requirements), extracted from the EURAD Roadmap goals breakdown structure (GBS). This is supplemented by typical activities, according to phases of implementation, needed to achieve the domain goal. Activities are generic and are common to most regional and geological disposal programmes.
description: Reviewers: Christophe BRUGGEMAN (SCK CEN), Paul CARBOL and Corinne BROSSARD (JRC), Tara BEATTIE (TB Environmental Services)
SSGP topologies on abelian groups of positive finite divisible rank
Creators: name: Shakhmatov, Dmitri
name: Yañez, Víctor Hugo
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Topology (math.GN)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: Primary: 22A05, Secondary: 03E99, 06A06, 20K27, 54E35, 54H11

description: Let G be an abelian group. For a subset A of G, Cyc(A) denotes the set of all elements x of G such that the cyclic subgroup generated by x is contained in A, and G is said to have the small subgroup generating property (abbreviated to SSGP) if the smallest subgroup of G generated by Cyc(U) is dense in G for every neighbourhood U of zero of G. SSGP groups form a proper subclass of the class of minimally almost periodic groups. Comfort and Gould asked for a characterization of abelian groups G which admit an SSGP group topology, and they solved this problem for bounded torsion groups (which have divisible rank zero). Dikranjan and the first author proved that an abelian group of infinite divisible rank admits an SSGP group topology. In the remaining case of positive finite divisible rank, the same authors found a necessary condition on G in order to admit an SSGP group topology and asked if this condition is also sufficient. We answer this question positively, thereby completing the characterization of abelian groups which admit an SSGP group topology.
description: First two sections of the original submission were revised and became first four sections of version 2
Implications of the complex Singlet field for Noncommutative Geometry model
Creators: name: Khozani, Hosein Karimi
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a complex singlet scalar in the spectral action approach to the standard model. It is shown that there is a range of initial values at the unification scale which is able to produce Higgs and top quark masses at low energies. The stability of the vacuum and the deviation of gauge couplings from experimental values are discussed and compared at the two-loop level with a real scalar singlet and the pure standard model.
description: 2 figures, 2 pages
title: Mission mines 2023 Gardanne : les conférences de l'OHM Bassin minier de Provence
Publisher: name: LabEx DRIIHM
Year: 2023

description: Cette collection regroupe les conférences réalisées par l'OHM Bassin minier de Provence dans le cadre de Mission mines 2023 organisé par la ville de Gardanne.
Optimal and Adaptive Off-policy Evaluation in Contextual Bandits
Creators: name: Wang, Yu-Xiang
name: Agarwal, Alekh
name: Dudik, Miroslav
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We study the off-policy evaluation problem---estimating the value of a target policy using data collected by another policy---under the contextual bandit model. We consider the general (agnostic) setting without access to a consistent model of rewards and establish a minimax lower bound on the mean squared error (MSE). The bound is matched up to constants by the inverse propensity scoring (IPS) and doubly robust (DR) estimators. This highlights the difficulty of the agnostic contextual setting, in contrast with multi-armed bandits and contextual bandits with access to a consistent reward model, where IPS is suboptimal. We then propose the SWITCH estimator, which can use an existing reward model (not necessarily consistent) to achieve a better bias-variance tradeoff than IPS and DR. We prove an upper bound on its MSE and demonstrate its benefits empirically on a diverse collection of data sets, often outperforming prior work by orders of magnitude.
Leveraging Quality Prediction Models for Automatic Writing Feedback
Creators: name: Nilforoshan, Hamed
name: Wu, Eugene
Publisher: name: arXiv
Year: 2017
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: User-generated, multi-paragraph writing is pervasive and important in many social media platforms (i.e. Amazon reviews, AirBnB host profiles, etc). Ensuring high-quality content is important. Unfortunately, content submitted by users is often not of high quality. Moreover, the characteristics that constitute high quality may even vary between domains in ways that users are unaware of. Automated writing feedback has the potential to immediately point out and suggest improvements during the writing process. Most approaches, however, focus on syntax/phrasing, which is only one characteristic of high-quality content. Existing research develops accurate quality prediction models. We propose combining these models with model explanation techniques to identify writing features that, if changed, will most improve the text quality. To this end, we develop a perturbation-based explanation method for a popular class of models called tree-ensembles. Furthermore, we use a weak-supervision technique to adapt this method to generate feedback for specific text segments in addition to feedback for the entire document. Our user study finds that the perturbation-based approach, when combined with segment-specific feedback, can help improve writing quality on Amazon (review helpfulness) and Airbnb (host profile trustworthiness) by > 14% (3X improvement over recent automated feedback techniques).
description: Accepted at the 12th International Conference on Web and Social Media (ICWSM), 2018
title: Αλγόριθμος αναζήτησης της μουσικής αρμονίας για το πρόβλημα δρομολόγησης οχημάτων με περιορισμό της ρύπανσης

title: A harmony search algorithm for the pollution-routing problem
Creators: name: Σηφακης Μιχαηλ
Publisher: name: Technical University of Crete
Year: 2023

description: Η διπλωματική εργασία ασχολείται με το πράσινο πρόβλημα ρύπανσης δρομολόγησης οχημάτων και προτείνει μια λύση με το συνδυασμό διάφορων αλγορίθμων. Ο στόχος είναι να βρεθεί μια βέλτιστη δρομολόγηση που μειώνει την εκπομπή αερίων των οχημάτων, μειώνοντας έτσι την ρύπανση και τον αντίκτυπο στο περιβάλλον.
description: The thesis deals with a green problem of the supply chain, the Pollution Routing Problem and proposes a solution by combining different algorithms. The goal is to find an optimal routing that reduces vehicle emissions, thereby reducing pollution and impact on the environment.
A counterexample to Hartogs' type extension of holomorphic line bundles
Creators: name: Chen, Zhangchi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: Consider a domain $\varOmega$ in $\mathbb{C}^n$ with $n\geqslant 2$ and a compact subset $K\subset\varOmega$ such that $\varOmega\backslash K$ is connected. We address the problem whether a holomorphic line bundle defined on $\varOmega\backslash K$ extends to $\varOmega$. In 2013, Fornæss, Sibony and Wold gave a positive answer in dimension $n\geqslant 3$, when $\varOmega$ is pseudoconvex and $K$ is a sublevel set of a strongly plurisubharmonic exhaustion function. However, for $K$ of general shape, we construct counterexamples in any dimension $n\geqslant 2$. The key is a certain gluing lemma by means of which we extend any two holomorphic line bundles which are isomorphic on the intersection of their base spaces.
description: 17 pages, 10 colored figures
Latest studies on the reaction e+ e- --> K + K- gamma
Creators: name: Lesniak, Leonard
name: Silarski, Michal
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Recent theoretical studies of the e+ e- --> K + K- gamma process are described. Three main reaction mechanisms are considered: the initial state radiation, the final state radiation and the strong interaction between the outgoing K+ K- mesons. The K+ K- effective mass distributions are derived for three different models which in past have been used for a description of the e+ e- --> pi+ pi- gamma data. Also the numerical results for the angular photon and kaon distributions are presented. A new model of the e+ e- --> M_1 M_2 gamma reactions is outlined which can serve for multichannel analyses of the radiative processes with a production of two pseudoscalar mesons M_1 and M_2.
description: 11 pages, 11 figures, presented by the first author at the KLOE-2 Workshop on e+ e- collider physics at 1 GeV, Frascati, Italy, October 26-28, 2016, figures 6-10 and tables have been corrected
Racial and Ethnic Disparities in Hospital-Based Care Among Dual Eligibles Who Use Health Centers
Creators: name: Wright, Brad
name: Wolinsky, Fredric D.
name: Stehlin, Grace G.
name: Trivedi, Amal N.
name: Akiyama, Jill
name: Potter, Andrew J.
name: Sabik, Lindsay M.
Publisher: name: Mary Ann Liebert
Year: 2023

description:
Introduction: Health center use may reduce hospital-based care among Medicare-Medicaid dual eligibles, but racial and ethnic disparities in this population have not been widely studied. We examined the extent of racial and ethnic disparities in hospital-based care among duals using health centers and the degree to which disparities occur within or between health centers. Methods: We used 2012-2018 Medicare claims and health center data to model emergency department (ED) visits, observation stays, hospitalizations, and 30-day unplanned returns as a function of race and ethnicity among dual eligibles using health centers. Results: In rural and urban counties, age-eligible Black individuals had more ED visits (7.9 [4.0, 11.7] and 13.7 [10.0, 17.4] per 100 person-years) and were more likely to experience an unplanned return (1.4 [0.4, 2.4] and 1 [0.4, 1.6] percentage points [pp]) than White individuals, but were less likely to be hospitalized (-3.3 [-3.9, -2.8] and -1.2 [-1.6, -0.9] pp). In urban counties, age-eligible Black individuals were 1.2 [0.9, 1.5] pp more likely than White individuals to have observation stays. Other racial and ethnic groups used the same or less hospital-based care than White individuals. Including state and health center fixed effects eliminated Black versus White disparities in all outcomes, except hospitalization. Results were similar among disability-eligible duals. Conclusion: Racial and ethnic disparities in hospital-based care among dual eligibles are less common within than between health centers. If health centers are to play a more central role in eliminating racial and ethnic health disparities, these differences across health centers must be understood and addressed.