cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Full self-consistency in Fermi-orbital self-interaction correction
Creators: name: Yang, Zeng-hui
name: Pederson, Mark R.
name: Perdew, John P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The Perdew-Zunger self-interaction correction cures many common problems associated with semilocal density functionals, but suffers from a size-extensivity problem when Kohn-Sham orbitals are used in the correction. Fermi-Löwdin-orbital self-interaction correction (FLOSIC) solves the size-extensivity problem, allowing its use in periodic systems and resulting in better accuracy in finite systems. Although the previously published FLOSIC algorithm [J. Chem. Phys. 140, 121103 (2014)] appears to work well in many cases, it is not fully self-consistent. This would be particularly problematic for systems where the occupied manifold is strongly changed by the correction. In this paper we demonstrate a new algorithm for FLOSIC to achieve full self-consistency with only marginal increase of computational cost. The resulting total energies are found to be lower than previously reported non-self-consistent results.
description: 8 pages, 5 figures
The most powerful astrophysical events: Gravitational-wave peak luminosity of binary black holes as predicted by numerical relativity
Creators: name: Keitel, David
name: Forteza, Xisco Jiménez
name: Husa, Sascha
name: London, Lionel
name: Nagar, Alessandro
name: Bernuzzi, Sebastiano
name: Harms, Enno
name: Hannam, Mark
name: Khan, Sebastian
name: Pürrer, Michael
name: Pratten, Geraint
name: Chaurasia, Vivek
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: For a brief moment, a binary black hole (BBH) merger can be the most powerful astrophysical event in the visible universe. Here we present a model fit for this gravitational-wave peak luminosity of nonprecessing quasicircular BBH systems as a function of the masses and spins of the component black holes, based on numerical relativity (NR) simulations and the hierarchical fitting approach introduced by X. Jiménez-Forteza et al. [Phys. Rev. D 95, 064024 (2017), arXiv:1611.00332]. This fit improves over previous results in accuracy and parameter-space coverage and can be used to infer posterior distributions for the peak luminosity of future astrophysical signals like GW150914 and GW151226. The model is calibrated to the l<=6 modes of 378 nonprecessing NR simulations up to mass ratios of 18 and dimensionless spin magnitudes up to 0.995, and includes unequal-spin effects. We also constrain the fit to perturbative numerical results for large mass ratios. Studies of key contributions to the uncertainty in NR peak luminosities, such as (i) mode selection, (ii) finite resolution, (iii) finite extraction radius, and (iv) different methods for converting NR waveforms to luminosity, allow us to use NR simulations from four different codes as a homogeneous calibration set. This study of systematic fits to combined NR and large-mass-ratio data, including higher modes, also paves the way for improved inspiral-merger-ringdown waveform models.
description: Updated to match PRD version. 22 pages, 22 figures, 6 tables; data and example implementations provided as supplementary material
A general framework to diagonalize vector--scalar and axial-vector--pseudoscalar transitions in the effective meson Lagrangian
Creators: name: Morais, Jorge
name: Hiller, Brigitte
name: Osipov, Alexander A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A new mathematical framework for the diagonalization of the nondiagonal vector--scalar and axial-vector--pseudoscalar mixing in the effective meson Lagrangian is described. This procedure has unexpected connections with the Hadamard product of $n\times n$ matrices describing the couplings, masses, and fields involved. The approach is shown to be much more efficient as compared with the standard methods employed previously. The difference is especially noticeable if the chiral symmetry is broken explicitly. The paper ends with an illustrative application to the chiral model with broken $SU(3)_L\times SU(3)_R$ symmetry.
description: 16 pages
Simulation of Patient Flow in Multiple Healthcare Units using Process and Data Mining Techniques for Model Identification
Creators: name: Kovalchuk, Sergey V.
name: Funkner, Anastasia A.
name: Metsker, Oleg G.
name: Yakovlev, Aleksey N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Introduction: An approach to building a hybrid simulation of patient flow is introduced with a combination of data-driven methods for automation of model identification. The approach is described with a conceptual framework and basic methods for combination of different techniques. The implementation of the proposed approach for simulation of acute coronary syndrome (ACS) was developed and used within an experimental study. Methods: Combination of data, text, and process mining techniques and machine learning approaches for analysis of electronic health records (EHRs) with discrete-event simulation (DES) and queueing theory for simulation of patient flow was proposed. The performed analysis of EHRs for ACS patients enable identification of several classes of clinical pathways (CPs) which were used to implement a more realistic simulation of the patient flow. The developed solution was implemented using Python libraries (SimPy, SciPy, and others). Results: The proposed approach enables more realistic and detailed simulation of the patient flow within a group of related departments. Experimental study shows that the improved simulation of patient length of stay for ACS patient flow obtained from EHRs in Federal Almazov North-west Medical Research Centre in Saint Petersburg, Russia. Conclusion: The proposed approach, methods, and solutions provide a conceptual, methodological, and programming framework for implementation of simulation of complex and diverse scenarios within a flow of patients for different purposes: decision making, training, management optimization, and others.
EU FAR Project: Description of Database EU Funds absorbed by Romanian Municipalities 2016-2021
Creators: name: Marin, Monica
name: Chiș, Alin
name: Corad, Bogdan
name: Glăvan, Eugen
Publisher: name: Zenodo
Year: 2022
Subjects: EU funds
local government
LAU
Romania
programming period
open science
urban
rural
municipalities
public administration

description: Description of the EU FAR Database: EU Funds absorbed by Romanian Municipalities 2016-2021.
Strong Convergence Rate of Splitting Schemes for Stochastic Nonlinear Schrödinger Equations
Creators: name: Cui, Jianbo
name: Hong, Jialin
name: Liu, Zhihui
name: Zhou, Weien
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: Primary 60H35, Secondary 60H15, 60G05

description: We prove the optimal strong convergence rate of a fully discrete scheme, based on a splitting approach, for a stochastic nonlinear Schrödinger (NLS) equation. The main novelty of our method lies on the uniform a priori estimate and exponential integrability of a sequence of splitting processes which are used to approximate the solution of the stochastic NLS equation. We show that the splitting processes converge to the solution with strong order $1/2$. Then we use the Crank--Nicolson scheme to temporally discretize the splitting process and get the temporal splitting scheme which also possesses strong order $1/2$. To obtain a full discretization, we apply this splitting Crank--Nicolson scheme to the spatially discrete equation which is achieved through the spectral Galerkin approximation. Furthermore, we establish the convergence of this fully discrete scheme with optimal strong convergence rate $\mathcal{O}(N^{-2}+τ^\frac12)$, where $N$ denotes the dimension of the approximate space and $τ$ denotes the time step size. To the best of our knowledge, this is the first result about strong convergence rates of temporally numerical approximations and fully discrete schemes for stochastic NLS equations, or even for stochastic partial differential equations (SPDEs) with non-monotone coefficients. Numerical experiments verify our theoretical result.
description: 39 pages
Selected U.S. Crop Budgets: Yields, Inputs, and Variable Costs, Volume V, South Central States
Creators: name: Strickland, P. L.
name: Harwell, R. Lynn
name: Strickland, P. L.
name: Harwell, R. Lynn
Publisher: name: Unknown
Year: 1971
Subjects: subject: Crop Production/Industries
subject: Labor and Human Capital
subject: Production Economics
subject: Productivity Analysis
subject: Research Methods/ Statistical Methods
subject: Crop costs
subject: Crop budgets
subject: Production costs
subject: South Central region

description: This report contains estimates of variable costs of producing major crops in 15 production areas in the South Central region of the United States. Crops include cotton, wheat, grain sorghum, forage sorghum, soybeans, oats, barley, alfalfa, and rice. Budgets show the quantity and value of specific preharvest and harvest inputs, total preharvest costs per acre planted, and total variable costs per acre planted. Detailed breakdowns of crop yields and rates of fertilization are also included.
Direct extraction of excitation energies from ensemble density-functional theory
Creators: name: Yang, Zeng-hui
name: Pribram-Jones, Aurora
name: Burke, Kieron
name: Ullrich, Carsten A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A very specific ensemble of ground and excited states is shown to yield an exact formula for any excitation energy as a simple correction to the energy difference between orbitals of the Kohn-Sham ground state. This alternative scheme avoids either the need to calculate many unoccupied levels as in time-dependent density functional theory (TDDFT) or the need for many self-consistent ensemble calculations. The symmetry-eigenstate Hartree-exchange (SEHX) approximation yields results comparable to standard TDDFT for atoms. With this formalism, SEHX yields approximate double-excitations, which are missed by adiabatic TDDFT.
description: 6 pages, 2 figures
Greatly enhanced merger rates of compact-object binaries in non-spherical nuclear star clusters
Creators: name: Petrovich, Cristobal
name: Antonini, Fabio
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Milky Way and a significant fraction of galaxies are observed to host a central Massive Black Hole (MBH) embedded in a non-spherical nuclear star cluster. We study the secular orbital evolution of compact-object binaries in these environments and characterize the excitation of extremely large eccentricities that can lead to mergers by gravitational radiation. We find that the eccentricity excitation occurs most efficiently when the nodal precession timescale of the binary's orbit around the MBH due to the non-spherical cluster becomes comparable (within a factor of ~10) to the timescale on which the binary is torqued by the MBH due to the Lidov-Kozai (LK) mechanism. We show that in this regime the perturbations due to the cluster increase the fraction of systems that reach extreme eccentricities ($1-e\sim10^{-4}-10^{-6}$) by a factor of ~10-100 compared to the idealized case of a spherical cluster, increasing the merger rates of compact objects by a similar factor. We identify two main channels that lead to this extreme eccentricity excitation: (i) chaotic diffusion of the eccentricities due to resonance overlap; (ii) cluster-driven variations of the mutual inclinations between the binary orbit and its center-of-mass orbit around the MBH, which can intensify the LK oscillations. We estimate that our mechanism can produce black hole-black hole and black hole-neutron star binary merger rates of up to $\approx 15$ $\rm{Gpc}^{-3}yr^{-1}$ and $\approx 0.4$ $\rm{Gpc}^{-3}yr^{-1}$, respectively. Thus, we propose the cluster-enhanced Lidov-Kozai mechanism as a new channel for the merger of compact-object binaries, competing with scenarios that invoke isolated binary evolution or dynamical formation in globular clusters.
description: 23 pages, 12 figures, accepted in ApJ
Nematic order on the surface of a three-dimensional topological insulator
Creators: name: Lundgren, Rex
name: Yerzhakov, Hennadii
name: Maciejko, Joseph
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the spontaneous breaking of rotational symmetry in the helical surface state of three-dimensional topological insulators due to strong electron-electron interactions, focusing on time-reversal invariant nematic order. Owing to the strongly spin-orbit coupled nature of the surface state, the nematic order parameter is linear in the electron momentum and necessarily involves the electron spin, in contrast with spin-degenerate nematic Fermi liquids. For a chemical potential at the Dirac point (zero doping), we find a first-order phase transition at zero temperature between isotropic and nematic Dirac semimetals. This extends to a thermal phase transition that changes from first to second order at a finite-temperature tricritical point. At finite doping, we find a transition between isotropic and nematic helical Fermi liquids that is second order even at zero temperature. Focusing on finite doping, we discuss various observable consequences of nematic order, such as anisotropies in transport and the spin susceptibility, the partial breakdown of spin-momentum locking, collective modes and induced spin fluctuations, and non-Fermi liquid behavior at the quantum critical point and in the nematic phase.
description: 12 pages, 6 figures. Corrected minor error in the definition of nematic order parameter
Solid state source of non-classical photon pairs with embedded multimode quantum memory
Creators: name: Kutluer, Kutlu
name: Mazzera, Margherita
name: de Riedmatten, Hugues
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The generation and distribution of quantum correlations between photonic qubits is a key resource in quantum information science. For applications in quantum networks and quantum repeaters, it is required that these quantum correlations be stored in a quantum memory. In 2001, Duan, Lukin, Cirac, and Zoller (DLCZ) proposed a scheme combining a correlated photon-pair source and a quantum memory in atomic gases, which has enabled fast progress towards elementary quantum networks. In this letter, we demonstrate a solid state source of correlated photon pairs with embedded spin-wave quantum memory, using a rare-earth doped crystal. We show strong quantum orrelations between the photons, high enough for performing quantum communication. Unlike the original DLCZ proposal, our scheme is inherently multimode thanks to a built-in rephasing mechanism, allowing us to demonstrate storage of 11 temporal modes. These results represent an important step towards the realization of complex quantum networks architectures using solid-state resources.
description: 6 pages, 4 figures
First-principles study of intersite magnetic couplings in NdFe$_{12}$ and NdFe$_{12}$X (X = B, C, N, O, F)
Creators: name: Fukazawa, Taro
name: Akai, Hisazumi
name: Harashima, Yosuke
name: Miyake, Takashi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a first-principles investigation of NdFe$_{12}$ and NdFe$_{12}$X (X = B, C, N, O, F) crystals with the ThMn$_{12}$ structure. Intersite magnetic couplings in these compounds, so-called exchange couplings, are estimated by Liechtenstein's method. It is found that the Nd--Fe couplings are sensitive to the interstitial dopant X, with the Nd--Fe(8j) coupling in particular reduced significantly for X = N. This suggests that the magnetocrystalline anisotropy decays quickly with rising temperature in the X = N system although nitrogenation has advantages over the other dopants in terms of enhancing low-temperature magnetic properties. The Curie temperature is also calculated from the magnetic couplings by using the mean field approximation. Introduction of X enhances the Curie temperature, with both structural changes and chemical effects found to play important roles in this enhancement.
description: 18 pages, 11 figures; data added to Appendix sections
Spontaneous photon production in time-dependent epsilon-near-zero materials
Creators: name: Prain, A.
name: Vezzoli, S.
name: Westerberg, N.
name: Roger, T.
name: Faccio, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Quantum field theory predicts that a spatially homogeneous but temporally varying medium will excite photon pairs out of the vacuum state. However, this important theoretical prediction lacks experimental verification due to the difficulty in attaining the required non-adiabatic and large amplitude changes in the medium. Recent work has shown that in epsilon-near-zero (ENZ) materials it is possible to optically induce changes of the refractive index of the order of unity, in femtosecond timescales. By studying the quantum field theory of a spatially homogeneous, time-varying ENZ medium, we theoretically predict photon pair production that is up to several orders of magnitude larger than in non-ENZ time-varying materials. We also find that whilst in standard materials the emission spectrum depends on the time scale of the perturbation, in ENZ materials the emission is always peaked at the ENZ wavelength. These studies pave the way to technologically feasible observation of photon pair emission from a time-varying background with implications for quantum field theories beyond condensed matter systems and with potential applications as a new source of entangled light.
description: 4 figures, accepted for publication in Phys. Rev. Lett
Nonlocal Kinetic Energy Functionals By Functional Integration
Creators: name: Mi, Wenhui
name: Genova, Alessandro
name: Pavanello, Michele
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Since the seminal works of Thomas and Fermi, researchers in the Density-Functional Theory (DFT) community are searching for accurate electron density functionals. Arguably, the toughest functional to approximate is the noninteracting Kinetic Energy, $T_s[ρ]$, the subject of this work. The typical paradigm is to first approximate the energy functional, and then take its functional derivative, $\frac{δT_s[ρ]}{δρ(r)}$, yielding a potential that can be used in orbital-free DFT, or subsystem DFT simulations. Here, this paradigm is challenged by constructing the potential from the second-functional derivative via functional integration. A new nonlocal functional for $T_s[ρ]$ is prescribed (which we dub MGP) having a density independent kernel. MGP is constructed to satisfy three exact conditions: (1) a nonzero "Kinetic electron" arising from a nonzero exchange hole; (2) the second functional derivative must reduce to the inverse Lindhard function in the limit of homogenous densities; (3) the potential derives from functional integration of the second functional derivative. Pilot calculations show that MGP is capable of reproducing accurate equilibrium volumes, bulk moduli, total energy, and electron densities for metallic (BCC, FCC) and semiconducting (CD) phases of Silicon as well as of III-V semiconductors. MGP functional is found to be numerically stable typically reaching selfconsistency within 12 iteration of a truncated Newton minimization algorithm. MGP's computational cost and memory requirements are low and comparable to the Wang-Teter (WT) nonlocal functional or any GGA functional.
A short-orbit spectrometer for low-energy pion detection in electroproduction experiments at MAMI
Creators: name: Baumann, D.
name: Ding, M.
name: Friščić, I.
name: Böhm, R.
name: Bosnar, D.
name: Distler, M. O.
name: Merkel, H.
name: Müller, U.
name: Walcher, Th.
name: Wendel, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A new Short-Orbit Spectrometer (SOS) has been constructed and installed within the experimental facility of the A1 collaboration at Mainz Microtron (MAMI), with the goal to detect low-energy pions. It is equipped with a Browne-Buechner magnet and a detector system consisting of two helium-ethane based drift chambers and a scintillator telescope made of five layers. The detector system allows detection of pions in the momentum range of 50 - 147 MeV/c, which corresponds to 8.7 - 63 MeV kinetic energy. The spectrometer can be placed at a distance range of 54 - 66 cm from the target center. Two collimators are available for the measurements, one having 1.8 msr aperture and the other having 7 msr aperture. The Short-Orbit Spectrometer has been successfully calibrated and used in coincidence measurements together with the standard magnetic spectrometers of the A1 collaboration.
description: 10 pages, 14 figures
A rough end for smooth microstate geometries
Creators: name: Marolf, Donald
name: Michel, Ben
name: Puhm, Andrea
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Supersymmetric microstate geometries with five non-compact dimensions have recently been shown by Eperon, Reall, and Santos (ERS) to exhibit a non-linear instability featuring the growth of excitations at an "evanescent ergosurface" of infinite redshift. We argue that this growth may be treated as adiabatic evolution along a family of exactly supersymmetric solutions in the limit where the excitations are Aichelburg-Sexl-like shockwaves. In the 2-charge system such solutions may be constructed explicitly, incorporating full backreaction, and are in fact special cases of known microstate geometries. In a near-horizon limit, they reduce to Aichelburg-Sexl shockwaves in $AdS_3 \times S^3$ propagating along one of the angular directions of the sphere. Noting that the ERS analysis is valid in the limit of large microstate angular momentum $j$, we use the above identification to interpret their instability as a transition from rare smooth microstates with large angular momentum to more typical microstates with smaller angular momentum. This entropic driving terminates when the angular momentum decreases to $j \sim \sqrt{n_1n_5}$ where the density of microstates is maximal. We argue that, at this point, the large stringy corrections to such microstates will render them non-linearly stable. We identify a possible mechanism for this stabilization and detail an illustrative toy model.
description: 22 pages, 1 figure. v2: JHEP version with references added
Exponential Stability of Nonlinear Differential Repetitive Processes with Applications to Iterative Learning Control
Creators: name: Altın, Berk
name: Barton, Kira
Publisher: name: arXiv
Year: 2017
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: This paper studies exponential stability properties of a class of two-dimensional (2D) systems called differential repetitive processes (DRPs). Since a distinguishing feature of DRPs is that the problem domain is bounded in the "time" direction, the notion of stability to be evaluated does not require the nonlinear system defining a DRP to be stable in the typical sense. In particular, we study a notion of exponential stability along the discrete iteration dimension of the 2D dynamics, which requires the boundary data for the differential pass dynamics to converge to zero as the iterations evolve. Our main contribution is to show, under standard regularity assumptions, that exponential stability of a DRP is equivalent to that of its linearized dynamics. In turn, exponential stability of this linearization can be readily verified by a spectral radius condition. The application of this result to Picard iterations and iterative learning control (ILC) is discussed. Theoretical findings are supported by a numerical simulation of an ILC algorithm.
description: 13 pages, 3 figures. Technical report accompanying "Exponential Stability of Nonlinear Differential Repetitive Processes with Applications to Iterative Learning Control" published in Automatica Volume 81, July 2017 (Pages 369-376, URL: http://www.sciencedirect.com/science/article/pii/S0005109817301772)
Full-Data Results of Hubble Frontier Fields: UV Luminosity Functions at $z\sim6-10$ and a Consistent Picture of Cosmic Reionization
Creators: name: Ishigaki, Masafumi
name: Kawamata, Ryota
name: Ouchi, Masami
name: Oguri, Masamune
name: Shimasaku, Kazuhiro
name: Ono, Yoshiaki
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present UV luminosity functions of dropout galaxies at $z\sim6-10$ with the complete Hubble Frontier Fields data. We obtain a catalog of $\sim450$ dropout-galaxy candidates (350, 66, and 40 at $z\sim6-7$, 8, and 9, respectively), whose UV absolute magnitudes reach $\sim-14$ mag, $\sim2$ mag deeper than the Hubble Ultra Deep Field detection limits. We carefully evaluate number densities of the dropout galaxies by Monte-Carlo simulations, including all lensing effects such as magnification, distortion, and multiplication of images as well as detection completeness and contamination effects in a self-consistent manner. We find that UV luminosity functions at $z\sim6-8$ have steep faint-end slopes, $α\sim-2$, and likely steeper slopes, $α\lesssim-2$ at $z\sim9-10$. We also find that the evolution of UV luminosity densities shows a non-accelerated decline beyond $z\sim8$ in the case of $M_\mathrm{trunc}=-15$, while an accelerated in the case of $M_\mathrm{trunc}=-17$. We examine whether our results are consistent with the Thomson scattering optical depth from the Planck satellite and the ionized hydrogen fraction $Q_\mathrm{HII}$ at $z\lesssim7$ based on the standard analytic reionization model. We find that there exist reionizaiton scenarios that consistently explain all the observational measurements with the allowed parameters of $f_{\rm esc}=0.17^{+0.07}_{-0.03}$ and $M_\mathrm{trunc}>-14.0$ for $\logξ_\mathrm{ion}/[\mathrm{erg}^{-1}\ \mathrm{Hz}]=25.34$, where $f_{\rm esc}$ is the escape fraction, $M_\mathrm{trunc}$ is the faint limit of the UV luminosity function, and $ξ_\mathrm{ion}$ is the conversion factor of the UV luminosity to the ionizing photon emission rate. The length of the reionization period is estimated to be $Δz=3.9^{+2.0}_{-1.6}$ (for $0.1
description: 21 pages, 10 figures. Accepted for publication in ApJ
Prospects for indirect MeV Dark Matter detection with Gamma Rays in light of Cosmic Microwave Background Constraints
Creators: name: Gonzalez-Morales, Alma X.
name: Profumo, Stefano
name: Reynoso-Córdova, Javier
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The self-annihilation of dark matter particles with mass in the MeV range can produce gamma rays via prompt or secondary radiation. The annihilation rate for such light dark matter particles is however tightly constrained by cosmic microwave background (CMB) data. Here we explore the possibility of discovering MeV dark matter annihilation with future MeV gamma-ray telescopes taking into account the latest and future CMB constraints. We study the optimal energy window as a function of the dominant annihilation final state. We consider both the (conservative) case of the dwarf spheroidal galaxy Draco and the (more optimistic) case of the Galactic center. We find that for certain channels, including those with one or two monochromatic photon(s) and one or two neutral pion(s), a detectable gamma-ray signal is possible for both targets under consideration, and compatible with CMB constraints. For other annihilation channels, however, including all leptonic annihilation channels and two charged pions, CMB data rule out any significant signal of dark matter annihilation at future MeV gamma-ray telescopes from dwarf galaxies, but possibly not for the Galactic center.
description: 10 pages, 6 figures, version to appear on PRD
The impact of COVID-19 on the philosophy of doing business in a sustainable environment
Creators: name: Britchenko, Igor
name: Polinkevych, Oksana
name: Trynchuk, Viktor
name: Khovrak, Inna
Publisher: name: figshare
Year: 2023
Subjects: Business analytics
Business systems in context

description: The article presents the results of the analysis of business philosophy changes under the influence of COVID-19 in the context of sustainable development. The aim of the article is to study the change in the philosophy of doing business under the influence of COVID-19 consequences and to highlight the main features of the philosophy and vectors of development. In the process of describing the business philosophy, the authors proposed an approach based on the criteria of sustainable development. The methodological basis of the study were methods of comparison, generalisation, analysis and synthesis, scientific abstraction, and expert evaluation. Characterisation of certain business philosophies was based on open public information on certain sectors of the economy, according to GICS. This approach enabled international comparability of research results. The authors found that the business philosophy has changed under the influence of COVID-19 and received an ecological, socio-psychological focus. Analysis of business philosophies allowed us to identify new slogans in the philosophy of generalised enterprises by sectors of the economy (industrial and consumer). The hypothesis that the business philosophy should be simple and customer-oriented has been confirmed. At the heart of this philosophy are social responsibility, economic aspects, corporate culture, and the goals of sustainable development.
Imaging the Real Space Structure of the Spin Fluctuations in an Iron-based superconductor
Creators: name: Chi, Shun
name: Aluru, Ramakrishna
name: Grothe, Stephanie
name: Kreisel, A.
name: Singh, Udai Raj
name: Andersen, Brian M.
name: Hardy, W. N.
name: Liang, Ruixing
name: Bonn, D. A.
name: Burke, S. A.
name: Wahl, Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Spin fluctuations are a leading candidate for the pairing mechanism in high temperature superconductors, supported by the common appearance of a distinct resonance in the spin susceptibility across the cuprates, iron-based superconductors and many heavy fermion materials. The information we have about the spin resonance comes almost exclusively from neutron scattering. Here we demonstrate that by using low-temperature scanning tunnelling microscopy and spectroscopy we can characterize the spin resonance in real space. We show that inelastic tunnelling leads to the characteristic dip-hump feature seen in tunnelling spectra in high temperature superconductors and that this feature arises from excitations of the spin fluctuations. Spatial mapping of this feature near defects allows us to probe non-local properties of the spin susceptibility and to image its real space structure.
description: published version (7 pages, 5 figures)
Quantum Critical Scaling under Periodic Driving
Creators: name: Lorenzo, Salvatore
name: Marino, Jamir
name: Plastina, Francesco
name: Palma, G. Massimo
name: Apollaro, Tony J. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Universality is key to the theory of phase transition stating that the equilibrium properties of observables near a phase transition can be classified according to few critical exponents. These exponents rule an universal scaling behaviour that witnesses the irrelevance of the model's microscopic details at criticality. Here we discuss the persistence of such a scaling in a one-dimensional quantum Ising model under sinusoidal modulation in time of its transverse magnetic field. We show that scaling of various quantities (concurrence, entanglement entropy, magnetic and fidelity susceptibility) endures up to a stroboscopic time $τ_{bd}$, proportional to the size of the system. This behaviour is explained by noticing that the low-energy modes, responsible for the scaling properties, are resilient to the absorption of energy. Our results suggest that relevant features of the universality do hold also when the system is brought out-of-equilibrium by a periodic driving.
description: 11 pages, 7 figures
Grand Unified Brane World Scenario
Creators: name: Arai, Masato
name: Blaschke, Filip
name: Eto, Minoru
name: Sakai, Norisuke
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a field theoretical model unifying grand unified theory (GUT) and brane world scenario. As a concrete example, we consider $SU(5)$ GUT in 4+1 dimensions where our 3+1 dimensional spacetime spontaneously arises on five domain walls. A field-dependent gauge kinetic term is used to localize massless non-Abelian gauge fields on the domain walls and to assure the charge universality of matter fields. We find the domain walls with the symmetry breaking $SU(5)\to SU(3)\times SU(2)\times U(1)$ as a global minimum and all the undesirable moduli are stabilized with the mass scale of $M_{\rm GUT}$. Profiles of massless Standard Model particles are determined as a consequence of wall dynamics. The proton decay can be exponentially suppressed.
description: 8 pages, 3 figures, Sections for introduction and conclusion are revised, references are added
An extension result for maps admitting an algebraic addition theorem
Creators: name: Baro, E.
name: de Vicente, J.
name: Otero, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 32A20 (Primary), 33E05, 14P20 (Secondary)

description: We prove that if an analytic map $f:=(f_1,\ldots ,f_n):U\subset \mathbb{C}^n\rightarrow \mathbb{C}^n$ admits an algebraic addition theorem then there exists a meromorphic map $g:=(g_1,\ldots ,g_n):\mathbb{C}^n\rightarrow \mathbb{C}^n$ admitting an algebraic addition theorem such that $f_1,\ldots ,f_n$ are algebraic over $\mathbb{C}(g_1,\ldots ,g_n)$ on $U$ (this was proved by K. Weierstrass in dimension $1$). Furthermore, $(g_1,\ldots ,g_n)$ admits a rational addition theorem.
description: The current paper is a reviewed version of part of arXiv:1506.00405 . A second paper extending the results of the rest of the mentioned paper --i.e. concerning locally K-Nash groups-- will appear subsequently. In the second version, the proof of the main result has been simplified. In the third version, the paper has been accepted for publication in the Journal of Geometric Analysis
Charge Transport and Entropy Production Rate in Magnetically Active Molecular Dimer
Creators: name: Jaramillo, J. D. Vasquez
name: Fransson, J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider charge and thermal transport properties of magnetically active paramagnetic molecular dimer. Generic properties for both transport quantities are reduced currents in the ferro- and anti-ferromagnetic regimes compared to the paramagnetic and efficient current blockade in the anti-ferromagnetic regime. In contrast, while the charge current is about an order of magnitude larger in the ferromagnetic regime, compared to the anti-ferromagnetic, the thermal current is efficiently blockaded there as well. This disparate behavior of the thermal current is attributed to current resonances in the ferromagnetic regime which counteract the thermal flow. The temperature difference strongly reduces the exchange interaction and tends to destroy the magnetic control of the transport properties. The weakened exchange interaction opens up a possibility to tune the system into thermal rectification, for both the charge and thermal currents.
description: 12 pages, 10 figures
SEAHIVE project Data
Creators: name: Mirdarsoltany, Mohammadamin
Publisher: name: Zenodo
Year: 2024

description: The uploaded file contains the raw data from the structural tests I conducted on the SEAHIVE model. These tests were performed to evaluate the structural integrity and resilience of the SEAHIVE design under various conditions. The results, along with the corresponding photos and detailed analysis in Excel format, are available in the provided link for further review and interpretation.
Born-Oppenheimer Dynamics, Electronic Friction, and the Inclusion of Electron-Electron Interactions
Creators: name: Dou, Wenjie
name: Miao, Gaohan
name: Subotnik, Joseph E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a universal expression for the electronic friction as felt by a set of classical nuclear degrees of freedom (DoF's) coupled to a manifold of quantum electronic DoF's; no assumptions are made regarding the nature of the electronic Hamiltonian and electron-electron repulsions are allowed. Our derivation is based on a quantum-classical Liouville equation (QCLE) for the coupled electronic-nuclear motion, followed by an adiabatic approximation whereby electronic transitions are assumed to equilibrate faster than nuclear movement. The resulting form of friction is completely general, but does reduce to previously published expressions for the quadratic Hamiltonian (i.e. Hamiltonians without electronic correlation). At equilibrium, the second fluctuation-dissipation theorem is satisfied and the frictional matrix is symmetric. To demonstrate the importance of electron-electron correlation, we study electronic friction within the Anderson-Holstein model, where a proper treatment of electron-electron interactions shows signatures of a Kondo resonance and a mean-field treatment is completely inadequate.
Checks of integrality properties in topological strings
Creators: name: Mironov, A.
name: Morozov, A.
name: Morozov, An.
name: Ramadevi, P.
name: Singh, Vivek Kumar
name: Sleptsov, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Tests of the integrality properties of a scalar operator in topological strings on a resolved conifold background or orientifold of conifold backgrounds have been performed for arborescent knots and some non-arborescent knots. The recent results on polynomials for those knots colored by SU(N) and SO(N) adjoint representations are useful to verify Marino's integrality conjecture up to two boxes in the Young diagram. In this paper, we review the salient aspects of the integrality properties and tabulate explicitly for an arborescent knot and a link. In our knotebook website, we have put these results for over 100 prime knots available in Rolfsen table and some links. The first application of the obtained results, an observation of the Gaussian distribution of the LMOV invariants is also reported.
description: 28 pages
Re-entrant charge order in overdoped (Bi,Pb)$_{2.12}$Sr$_{1.88}$CuO$_{6+δ}$ outside the pseudogap regime
Creators: name: Peng, Y. Y.
name: Fumagalli, R.
name: Ding, Y.
name: Minola, M.
name: Caprara, S.
name: Betto, D.
name: De Luca, G. M.
name: Kummer, K.
name: Lefrançois, E.
name: Salluzzo, M.
name: Suzuki, H.
name: Tacon, M. Le
name: Zhou, X. J.
name: Brookes, N. B.
name: Keimer, B.
name: Braicovich, L.
name: Grilli, M.
name: Ghiringhelli, G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Charge modulations are considered as a leading competitor of high-temperature superconductivity in the underdoped cuprates, and their relationship to Fermi surface reconstructions and to the pseudogap state is an important subject of current research. Overdoped cuprates, on the other hand, are widely regarded as conventional Fermi liquids without collective electronic order. For the overdoped (Bi,Pb)2.12Sr1.88CuO6+δ (Bi2201) high-temperature superconductor, here we report resonant x-ray scattering measurements revealing incommensurate charge order reflections, with correlation lengths of 40-60 lattice units, that persist up to at least 250K. Charge order is markedly more robust in the overdoped than underdoped regime but the incommensurate wave vectors follow a common trend; moreover it coexists with a single, unreconstructed Fermi surface, without pseudogap or nesting features, as determined from angle-resolved photoemission spectroscopy. This re-entrant charge order is reproduced by model calculations that consider a strong van Hove singularity within a Fermi liquid framework.
description: 11 pages, 5 figures
Shift-Coupling of Random Rooted Graphs and Networks
Creators: name: Khezeli, Ali
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60C05 (Primary), 60K99, 05C80 (Secondary)

description: In this paper, we present a result similar to the shift-coupling result of Thorisson (1996) in the context of random graphs and networks. The result is that a given random rooted network can be obtained by changing the root of another given one if and only if the distributions of the two agree on the invariant sigma-field. Several applications of the result are presented for the case of unimodular networks. In particular, it is shown that the distribution of a unimodular network is uniquely determined by its restriction to the invariant sigma-filed. Also, the theorem is applied to the existence of an invariant transport kernel that balances between two given (discrete) measures on the vertices. An application is the existence of a so called extra head scheme for the Bernoulli process on an infinite unimodular graph. Moreover, a construction is presented for balancing transport kernels that is a generalization of the Gale-Shapley stable matching algorithm in bipartite graphs. Another application is on a general method that covers the situations where some vertices and edges are added to a unimodular network and then, to make it unimodular, the probability measure is biased and then a new root is selected. It is proved that this method provides all possible unimodularizations in these situations. Finally, analogous existing results for stationary point processes and unimodular networks are discussed in detail.
description: 34 pages
Spin-Frustrated Pyrochlore Chains in the Volcanic Mineral Kamchatkite (KCu3OCl(SO4)2)
Creators: name: Volkova, L. M.
name: Marinin, D. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Search of new frustrated magnetic systems is of a significant importance for physics studying the condensed matter. The platform for geometric frustration of magnetic systems can be provided by copper oxocentric tetrahedra (OCu4) forming the base of crystalline structures of copper minerals from Tolbachik volcanos in Kamchatka. The present work was devoted to a new frustrated antiferromagnetic - kamchatkite (KCu3OCl(SO4)2). The calculation of the sign and strength of magnetic couplings in KCu3OCl(SO4)2 has been performed on the basis of structural data by the phenomenological crystal chemistry method with taking into account corrections on the Jahn-Teller orbital degeneracy of Cu2. It has been established that kamchatkite (KCu3OCl(SO4)2) contains AFM spin-frustrated chains of the pyrochlore type composed of cone-sharing Cu4 tetrahedra. Strong AFM intrachain and interchain couplings compete with each other. Frustration of magnetic couplings in tetrahedral chains is combined with the presence of electric polarization.
description: 14 pages, 7 figures, and 2 tables. As accepted on 23 th January 2018 for publication in Physics and Chemistry of Minerals, for which see http://rdcu.be/GLyy
Vanishing lines for modules over the motivic Steenrod algebra
Creators: name: Heard, Drew
name: Krause, Achim
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 14F42, 55S10

description: We study criteria for freeness and for the existence of a vanishing line for modules over certain Hopf subalgebras of the motivic Steenrod algebra over $\mathrm{Spec}(\mathbb{C})$ at the prime 2. These turn out to be determined by the vanishing of certain Margolis homology groups in the quotient Hopf algebra $\mathcal{A}/τ$.
description: Version to appear (with minor typesetting changes) in New York Journal of Mathematics
Hydrodynamic and entropic effects on colloidal diffusion in corrugated channels
Creators: name: Yang, Xiang
name: Liu, Chang
name: Li, Yunyun
name: Marchesoni, Fabio
name: Hänggi, Peter
name: Zhang, H. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: In the absence of advection, confined diffusion characterizes transport in many natural and artificial devices, such as ionic channels, zeolites, and nanopores. While extensive theoretical and numerical studies on this subject have produced many important predictions, experimental verifications of the predictions are rare. Here, we experimentally measure colloidal diffusion times in microchannels with periodically varying width and contrast results with predictions from the Fick-Jacobs theory and Brownian dynamics simulation. While the theory and simulation correctly predict the entropic effect of the varying channel width, they fail to account for hydrodynamic effects, which include both an overall decrease and a spatial variation of diffusivity in channels. Neglecting such hydrodynamic effects, the theory and simulation underestimate the mean and standard deviation of first passage times by 40\% in channels with a neck width twice the particle diameter. We further show that the validity of the Fick-Jakobs theory can be restored by reformulating it in terms of the experimentally measured diffusivity. Our work thus demonstrates that hydrodynamic effects play a key role in diffusive transport through narrow channels and should be included in theoretical and numerical models.
description: 7 pages, 4 figures