publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2010-06-25 | Molecular Dynamics at Low Time Resolution | The internal dynamics of macro-molecular systems is characterized by widely
separated time scales, ranging from fraction of ps to ns. In ordinary molecular
dynamics simulations, the elementary time step dt used to integrate the
equation of motion needs to be chosen much smaller of the shortest time scale,
in order not ... | 1006.5045v1 |
2010-07-15 | Universal Quantum Viscosity in a Unitary Fermi Gas | A Fermi gas of atoms with resonant interactions is predicted to obey
universal hydrodynamics, where the shear viscosity and other transport
coefficients are universal functions of the density and temperature. At low
temperatures, the viscosity has a universal quantum scale $\hbar n$ where $n$
is the density, while at h... | 1007.2625v2 |
2010-07-26 | Phase-Field Reaction-Pathway Kinetics of Martensitic Transformations in a Model Fe3Ni Alloy | A three-dimensional phase-field approach to martensitic transformations that
uses reaction pathways in place of a Landau potential is introduced and applied
to a model of Fe3Ni. Pathway branching involves an unbounded set of variants
through duplication and rotations by the rotation point groups of the austenite
and ma... | 1007.4515v1 |
2010-08-07 | Fermi acceleration and suppression of Fermi acceleration in a time-dependent Lorentz Gas | We study some dynamical properties of a Lorentz gas. We have considered both
the static and time dependent boundary. For the static case we have shown that
the system has a chaotic component characterized with a positive Lyapunov
Exponent. For the time-dependent perturbation we describe the model using a
four-dimension... | 1008.1344v2 |
2010-11-01 | Terahertz surface plasmons in optically pumped graphene structures | We analyze the surface plasmons (SPs) propagating along the optically pumped
single-graphene layer (SGL) and multiple-graphene layer (MGL) structures. It is
shown that at sufficiently strong optical pumping when the real part of dynamic
conductivity of SGL and MGL structures becomes negative in the terahertz (THz)
rang... | 1011.0238v1 |
2010-11-01 | In-flight dissipation as a mechanism to suppress Fermi acceleration | Some dynamical properties of time-dependent driven elliptical-shaped billiard
are studied. It was shown that for the conservative time-dependent dynamics the
model exhibits the Fermi acceleration [Phys. Rev. Lett. 100, 014103 (2008)]. On
the other hand, it was observed that damping coefficients upon collisions
suppress... | 1011.0419v1 |
2010-12-29 | Dependence of boundary lubrication on the misfit angle between the sliding surfaces | Using molecular dynamics based on Langevin equations with a coordinate- and
velocity-dependent damping coefficient, we study the frictional properties of a
thin layer of "soft" lubricant (where the interaction within the lubricant is
weaker than the lubricant-substrate interaction) confined between two solids.
At low d... | 1012.5922v1 |
2010-12-31 | Structural optimization of the Ziegler's pendulum: singularities and exact optimal solutions | Structural optimization of non-conservative systems with respect to stability
criteria is a research area with important applications in fluid-structure
interactions, friction-induced instabilities, and civil engineering. In
contrast to optimization of conservative systems where rigorously proven
optimal solutions in b... | 1101.0246v1 |
2011-01-24 | Boundary crisis and suppression of Fermi acceleration in a dissipative two dimensional non-integrable time-dependent billiard | Some dynamical properties for a dissipative time-dependent oval-shaped
billiard are studied. The system is described in terms of a four-dimensional
nonlinear mapping. Dissipation is introduced via inelastic collisions of the
particle with the boundary, thus implying that the particle has a fractional
loss of energy upo... | 1101.4593v1 |
2011-04-14 | Phenomenological modeling of long range noncontact friction in micro- and nanoresonators | Motivated by the results of an experiment using atomic force microscopy
performed by Gotsmann and Fuchs [Phys. Rev. Lett. {\bf 86}, 2597 (2001)], where
a strong energy loss due to the tip-sample interaction was measured, we
investigate the potential implications of this energy loss channel to the
quality factor of susp... | 1104.2832v2 |
2011-05-03 | Nonequilibrium chiral fluid dynamics including dissipation and noise | We present a consistent theoretical approach for the study of nonequilibrium
effects in chiral fluid dynamics within the framework of the linear sigma model
with constituent quarks. Treating the quarks as an equilibrated heat bath we
use the influence functional formalism to obtain a Langevin equation for the
sigma fie... | 1105.0622v1 |
2011-05-05 | Long-range three-body atom-diatom potential for doublet Li${}_3$ | An accurate long-range {\em ab initio} potential energy surface has been
calculated for the ground state ${}^2A'$ lithium trimer in the frozen diatom
approximation using all electron RCCSD(T). The {\em ab initio} energies are
corrected for basis set superposition error and extrapolated to the complete
basis limit. Mole... | 1105.1090v2 |
2011-05-12 | Searching for Perfect Fluids: Quantum Viscosity in a Universal Fermi Gas | We measure the shear viscosity in a two-component Fermi gas of atoms, tuned
to a broad s-wave collisional (Feshbach) resonance. At resonance, the atoms
strongly interact and exhibit universal behavior, where the equilibrium
thermodynamic properties and the transport coefficients are universal functions
of the density $... | 1105.2496v1 |
2011-05-21 | Stochastic population oscillations in spatial predator-prey models | It is well-established that including spatial structure and stochastic noise
in models for predator-prey interactions invalidates the classical
deterministic Lotka-Volterra picture of neutral population cycles. In contrast,
stochastic models yield long-lived, but ultimately decaying erratic population
oscillations, whi... | 1105.4242v1 |
2011-06-17 | Sequential vibrational resonance in multistable systems | The phenomenon of sequential vibrational resonance existed in a multistable
system that is excited by both high- and low-frequency signals is reported. By
the method of direct separation of motions, the theoretical investigation on
vibrational resonance is conducted in both cases of underdamped and overdamped,
and the ... | 1106.3431v1 |
2011-10-27 | Existence of global strong solutions for the shallow-water equations with large initial data | This work is devoted to the study of a viscous shallow-water system with
friction and capillarity term. We prove in this paper the existence of global
strong solutions for this system with some choice of large initial data when
$N\geq 2$ in critical spaces for the scaling of the equations. More precisely,
we introduce ... | 1110.6100v1 |
2011-10-28 | Nonlinear instability of solutions in parabolic and hyperbolic diffusion | We consider semilinear evolution equations of the form $a(t)\partial_{tt}u +
b(t) \partial_t u + Lu = f(x,u)$ and $b(t) \partial_t u + Lu = f(x,u),$ with
possibly unbounded $a(t)$ and possibly sign-changing damping coefficient
$b(t)$, and determine precise conditions for which linear instability of the
steady state sol... | 1110.6240v3 |
2011-11-09 | Numerical stability of the Z4c formulation of general relativity | We study numerical stability of different approaches to the discretization of
a conformal decomposition of the Z4 formulation of general relativity. We
demonstrate that in the linear, constant coefficient regime a novel
discretization for tensors is formally numerically stable with a method of
lines time-integrator. We... | 1111.2177v1 |
2012-01-30 | Non-contact Friction and Relaxational Dynamics of Surface Defects | Motion of cantilever near sample surfaces exhibits additional friction even
before two bodies come into mechanical contact. Called non-contact friction
(NCF), this friction is of great practical importance to the ultrasensitive
force detection measurements. Observed large NCF of a micron-scale cantilever
found anomalou... | 1201.6378v1 |
2012-02-09 | Casimir-Polder interaction of fullerene molecules with surfaces | We calculate the thermal Casimir--Polder potential of C60 and C70 fullerene
molecules near gold and silicon nitride surfaces, motivated by their relevance
for molecular matter wave interference experiments. We obtain the coefficients
governing the asymptotic power laws of the interaction in the thermal, retarded
and no... | 1202.1982v1 |
2012-04-30 | New integrability case for the Riccati equation | A new integrability condition of the Riccati equation
$dy/dx=a(x)+b(x)y+c(x)y^{2}$ is presented. By introducing an auxiliary equation
depending on a generating function $f(x)$, the general solution of the Riccati
equation can be obtained if the coefficients $a(x)$, $b(x)$, $c(x)$, and the
function $f(x)$ satisfy a part... | 1204.6546v1 |
2012-06-23 | Superlattice formed by quantum-dot sheets: density of states and IR absorption | Low-energy continuous states of electron in heterosrtucture with periodically
placed quantum-dot sheets are studied theoretically. The Green's function of
electron is governed by the Dyson equation with the self-energy function which
is determined the boundary conditions at quantum-dot sheets with weak damping
in low-e... | 1206.5418v1 |
2012-07-27 | Spin transition rates in nanowire superlattices: Rashba spin-orbit coupling effects | We investigate the influence of Rashba spin-orbit coupling in a parabolic
nanowire modulated by longitudinal periodic potential. The modulation potential
can be obtained from realistically grown supperlattices (SLs). Our study shows
that the Rashba spin-orbit interaction induces the level crossing point in the
paraboli... | 1207.6580v2 |
2012-09-24 | Non-stationary Magnetic Microstructures in Stellar Thin Accretion Discs | We examine the morphology of magnetic structures in thin plasma accretion
discs, generalizing a stationary ideal MHD model to the time-dependent
visco-resistive case. Our analysis deals with small scale perturbations to a
central dipole-like magnetic field, which give rise -- as in the ideal case --
to the periodic mod... | 1209.5227v2 |
2013-03-22 | Scattering Rates For Leptogenesis: Damping of Lepton Flavour Coherence and Production of Singlet Neutrinos | Using the Closed-Time-Path approach, we perform a systematic leading order
calculation of the relaxation rate of flavour correlations of left-handed
Standard Model leptons. This quantity is of pivotal relevance for flavoured
Leptogenesis in the Early Universe, and we find it to be 5.19*10^-3 T at T=10^7
GeV and 4.83*10... | 1303.5498v1 |
2013-06-18 | Spinor dynamics in an antiferromagnetic spin-1 thermal Bose gas | We present experimental observations of coherent spin-population oscillations
in a cold thermal, Bose gas of spin-1 sodium-23 atoms. The population
oscillations in a multi-spatial-mode thermal gas have the same behavior as
those observed in a single-spatial-mode antiferromagnetic spinor Bose Einstein
condensate. We dem... | 1306.4255v1 |
2013-06-19 | Soliton dynamics in an extended nonlinear Schrodinger equation with a spatial counterpart of the stimulated Raman scattering | Dynamics of solitons is considered in the framework of the extended nonlinear
Schrodinger equation (NLSE), which is derived from a system of Zakharov's type
for the interaction between high- and low-frequency (HF and LF) waves, in which
the LF field is subject to diffusive damping. The model may apply to the
propagatio... | 1306.4550v1 |
2013-09-18 | On an auto-controlled global existence scheme of the incompressible Navier Stokes equation | We propose a global scheme for the incompressible Navier Stokes equation,
where at each time step a damping potential term is introduced via a time
dilation transformation of the equation itself. This leads a global upper
bounds of the value function and its spatial derivatives. The regularity is
limited only by the re... | 1309.4824v11 |
2013-10-21 | Cosmic ray propagation in galactic turbulence | We revisit propagation of galactic cosmic rays (CRs) in light of recent
advances in CR diffusion theory in realistic interstellar turbulence. We use a
tested model of turbulence in which it has been shown that fast modes dominate
scattering of CRs. As a result, propagation becomes inhomogeneous and
environment dependen... | 1310.5732v2 |
2013-10-23 | Spectroscopic investigation of local mechanical impedance of living cells | The mechanical properties of PC12 living cells have been studied at the
nanoscale with a Force Feedback Microscope using two experimental approaches.
Firstly, the local mechanical impedance of the cell membrane has been mapped
simultaneously to the cell morphology at constant force. As the force of the
interaction is g... | 1310.6201v1 |
2013-11-21 | Note on the super inflation in loop quantum cosmology | Phenomenological effect of the super-inflation in loop quantum cosmology
(LQC) is discussed. We investigate the case that the Universe is filled with
the interacting field between massive scalar field and radiation. Considering
the damping coefficient $\Gamma$ as a constant, the changes of the scale factor
during super... | 1311.5325v1 |
2013-12-10 | Delaying the waterfall transition in warm hybrid inflation | We analyze the dynamics and observational predictions of supersymmetric
hybrid inflation in the warm regime, where dissipative effects are mediated by
the waterfall fields and their subsequent decay into light degrees of freedom.
This produces a quasi-thermal radiation bath with a slowly-varying temperature
during infl... | 1312.2961v1 |
2013-12-11 | Modelling of the optical properties of silver with use of six fitting parameters | We propose a realistic model of the optical properties of silver, in which
inter-band transition with a threshold energy of ~ 4 eV is described
phenomenologically by an ensemble of oscillators with same damping constant and
a certain distribution of resonant frequencies in the interband transition
threshold to infinity... | 1312.3100v1 |
2014-02-17 | Spatio-temporal dynamics of an active, polar, viscoelastic ring | Constitutive equations for a one-dimensional, active, polar, viscoelastic
liquid are derived by treating the strain field as a slow hydrodynamic
variable. Taking into account the couplings between strain and polarity allowed
by symmetry, the hydrodynamics of an active, polar, viscoelastic body include
an evolution equa... | 1402.3987v1 |
2014-05-14 | An exactly solvable $\mathcal{PT}$-symmetric dimer from a Hamiltonian system of nonlinear oscillators with gain and loss | We show that a pair of coupled nonlinear oscillators, of which one oscillator
has positive and the other one negative damping of equal rate, can form a
Hamiltonian system. Small-amplitude oscillations in this system are governed by
a $\mathcal{PT}$-symmetric nonlinear Schr\"odinger dimer with linear and cubic
coupling.... | 1405.3588v2 |
2014-07-02 | Basins of attraction in forced systems with time-varying dissipation | We consider dissipative periodically forced systems and investigate cases in
which having information as to how the system behaves for constant dissipation
may be used when dissipation varies in time before settling at a constant final
value. First, we consider situations where one is interested in the basins of
attrac... | 1407.0556v1 |
2014-09-24 | Scaling laws for the bifurcation-escape rate in a nanomechanical resonator | We report on experimental and theoretical studies of the fluctuation-induced
escape time from a metastable state of a nanomechanical Duffing resonator in
cryogenic environment. By tuning in situ the non-linear coefficient $\gamma$ we
could explore a wide range of the parameter space around the bifurcation point,
where ... | 1409.6971v3 |
2014-09-30 | Numerical Simulation of Two Dimentional sine-Gordon Solitons Using the Modified Cubic B-Spline Differential Quadrature Method | In this article, a numerical simulation of two dimensional nonlinear
sine-Gordon equation with Neumann boundary condition is obtained by using a
composite scheme referred to as a modified cubic B spline differential
quadrature method. The modified cubic B-spline serves as a basis function in
the differential quadrature... | 1410.0058v1 |
2014-11-12 | Semi-active Suspension Control using Modern Methodology: Comprehensive Comparison Study | Semi-active suspensions have drawn particular attention due to their superior
performance over the other types of suspensions. One of their advantages is
that their damping coefficient can be controlled without the need for any
external source of power. In this study, three control approaches are
implemented on a quart... | 1411.3305v1 |
2015-03-19 | Quasinormal modes of test fields around regular black holes | We study scalar, electromagnetic and gravitational test fields in the
Hayward, Bardeen and Ay\'on-Beato-Garc\'ia regular black hole spacetimes and
demonstrate that the test fields are stable in all these spacetimes. Using the
sixth order WKB approximation of the linear "axial" perturbative scheme, we
determine dependen... | 1503.05737v2 |
2015-04-03 | Role of attractive forces in determining the equilibrium structure and dynamics of simple liquids | Molecular Dynamics simulations of a Lennard-Jones system with different range
of attraction show that the attractive forces modify the radial distribution of
the particles. For condensed liquids only, the forces within the the first
coordination shell (FCS) are important, but for gases and moderate condensed
fluids, ev... | 1504.00809v1 |
2015-06-08 | Another derivation of generalized Langevin equations | The formal derivation of Langevin equations (and, equivalently Fokker-Planck
equations) with projection operator techniques of Mori, Zwanzig, Kawasaki and
others apparently not has widely found its way into textbooks. It has been
reproduced dozens of times on the fly with many references to the literature
and without a... | 1506.02650v2 |
2015-06-09 | Sensitivity analysis for shape optimization of a focusing acoustic lens in lithotripsy | We are interested in shape sensitivity analysis for an optimization problem
arising in medical applications of high intensity focused ultrasound. The goal
is to find the optimal shape of a focusing acoustic lens so that the desired
acoustic pressure at a kidney stone is achieved. Coupling of the silicone
acoustic lens ... | 1506.02781v1 |
2015-06-26 | Dimer with gain and loss: Integrability and $\mathcal{PT}$-symmetry restoration | A $\mathcal{PT}$-symmetric nonlinear Schr\"odinger dimer is a two-site
discrete nonlinear Schr\"odinger equation with one site losing and the other
one gaining energy at the same rate. In this paper, two four-parameter families
of cubic $\mathcal{PT}$-symmetric dimers are constructed as gain-loss
extensions of their co... | 1506.08229v2 |
2015-07-09 | Background field method in the gradient flow | In perturbative consideration of the Yang--Mills gradient flow, it is useful
to introduce a gauge non-covariant term ("gauge-fixing term") to the flow
equation that gives rise to a Gaussian damping factor also for gauge degrees of
freedom. In the present paper, we consider a modified form of the gauge-fixing
term that ... | 1507.02360v3 |
2015-07-16 | Fast Convergence of an Inertial Gradient-like System with Vanishing Viscosity | In a real Hilbert space $\mathcal H$, we study the fast convergence
properties as $t \to + \infty$ of the trajectories of the second-order
evolution equation $$ \ddot{x}(t) + \frac{\alpha}{t} \dot{x}(t) + \nabla \Phi
(x(t)) = 0, $$ where $\nabla \Phi$ is the gradient of a convex continuously
differentiable function $\P... | 1507.04782v1 |
2015-07-29 | Gravitational, shear and matter waves in Kantowski-Sachs cosmologies | A general treatment of vorticity-free, perfect fluid perturbations of
Kantowski-Sachs models with a positive cosmological constant are considered
within the framework of the 1+1+2 covariant decomposition of spacetime. The
dynamics is encompassed in six evolution equations for six harmonic
coefficients, describing gravi... | 1507.08300v2 |
2015-08-14 | Reactive collisions of polar molecules in quasi-two-dimensional traps | We investigate collisions of polar molecules in quasi-2D traps in the
presence of an external electric field perpendicular to the collision plane. We
use the quantum-defect model characterized by two dimensionless parameters: $y$
and $s$. The first of them is related to the probability of the reaction at
short distance... | 1508.03443v1 |
2015-11-06 | Curvature and torsion effects in the spin-current driven domain wall motion | The domain wall motion along a helix-shaped nanowire is studied for the case
of spin-current driving via Bazaliy-Zhang-Li mechanism. The analysis is based
on collective variable approach. Two new effects are ascertained: (i) the
curvature results in appearance of the Walker limit for a uniaxial wire, (ii)
the torsion r... | 1511.02193v1 |
2015-11-15 | Fluid friction and wall viscosity of the 1D blood flow model | We study the behavior of the pulse waves of water into a flexible tube for
application to blood flow simulations. In pulse waves both fluid friction and
wall viscosity are damping factors, and difficult to evaluate separately. In
this paper, the coefficients of fluid friction and wall viscosity are estimated
by fitting... | 1511.04729v1 |
2016-01-10 | Classic Calculations of Static Properties of the Nucleons reexamined | Classic calculations of the magnetic moments mu_p and mu_n of the nucleons
using the traditional exponential kernel show instability with respect to
variations of the Borel mass as well as arbitrariness with respect to the
choice of the onset of perturbative QCD. The use of a polynomial kernel, the
coefficients of whic... | 1601.02247v2 |
2016-01-28 | Dynamic system classifier | Stochastic differential equations describe well many physical, biological and
sociological systems, despite the simplification often made in their
derivation. Here the usage of simple stochastic differential equations to
characterize and classify complex dynamical systems is proposed within a
Bayesian framework. To thi... | 1601.07901v2 |
2016-05-11 | Electromagnetic properties of a double layer graphene system with electron-hole pairing | We study electromagnetic properties of a double layer graphene system in
which electrons from one layer are coupled with holes from the other layer. The
gauge invariant linear response functions are obtained. The frequency
dependences of the transmission, reflection and absorption coefficients are
computed. We predict ... | 1605.03307v1 |
2016-08-02 | Nonperturbative quasi-classical theory of the nonlinear electrodynamic response of graphene | An electromagnetic response of a single graphene layer to a uniform,
arbitrarily strong electric field $E(t)$ is calculated by solving the kinetic
Boltzmann equation within the relaxation-time approximation. The theory is
valid at low (microwave, terahertz, infrared) frequencies satisfying the
condition $\hbar\omega\le... | 1608.00877v2 |
2016-09-23 | Underdamped scaled Brownian motion: (non-)existence of the overdamped limit in anomalous diffusion | It is quite generally assumed that the overdamped Langevin equation provides
a quantitative description of the dynamics of a classical Brownian particle in
the long time limit. We establish and investigate a paradigm anomalous
diffusion process governed by an underdamped Langevin equation with an explicit
time dependen... | 1609.07250v1 |
2016-11-25 | Random and quasi-coherent aspects in particle motion and their effects on transport and turbulence evolution | The quasi-coherent effects in two-dimensional incompressible turbulence are
analyzed starting from the test particle trajectories. They can acquire
coherent aspects when the stochastic potential has slow time variation and the
motion is not strongly perturbed. The trajectories are, in these conditions,
random sequences... | 1611.08521v1 |
2017-01-07 | A quantitative description of Nernst effect in high-temperature superconductors | A quantitative vortex-fluid model for flux-flow resistivity $\rho$ and Nernst
signal $e_N$ in high-temperature superconductors (HTSC) is proposed. Two kinds
of vortices, magnetic and thermal, are considered, and the damping viscosity
$\eta$ is modeled by extending the Bardeen-Stephen model to include the
contributions ... | 1701.01832v1 |
2017-01-23 | Understanding stability diagram of perpendicular magnetic tunnel junctions | Perpendicular magnetic tunnel junctions (MTJ) with a bottom pinned reference
layer and a composite free layer (FL) are investigated. Different thicknesses
of the FL were tested to obtain an optimal balance between tunneling
magnetoresistance (TMR) ratio and perpendicular magnetic anisotropy. After
annealing at 400 $^\c... | 1701.06411v1 |
2017-01-27 | Evaluating the Friction of Rotary Joints in Molecular Machines | A computationally-efficient method for evaluating friction in molecular
rotary bearings is presented. This method estimates drag from fluctuations in
molecular dynamics simulations via the fluctuation-dissipation theorem. This is
effective even for simulation times short compared to a bearing's energy
damping time and ... | 1701.08202v2 |
2017-04-01 | Homogenization for a Class of Generalized Langevin Equations with an Application to Thermophoresis | We study a class of systems whose dynamics are described by generalized
Langevin equations with state-dependent coefficients. We find that in the
limit, in which all the characteristic time scales vanish at the same rate, the
position variable of the system converges to a homogenized process, described
by an equation c... | 1704.00134v2 |
2017-04-03 | Parametrization of the Tkatchenko-Scheffler dispersion correction scheme for popular exchange-correlation density functionals: effect on the description of liquid water | We present a list of optimized damping range parameters $s_R$ to be used with
the Tkatchenko-Scheffler van der Waals dispersion-correction scheme [Phys. Rev.
Lett. 102, 073005 (2009)]. The optimal $s_R$ are obtained for seven popular
generalized-gradient approximation exchange-correlation density functionals:
PBE, RPBE... | 1704.00761v2 |
2017-04-13 | Stochastic Gradient Descent as Approximate Bayesian Inference | Stochastic Gradient Descent with a constant learning rate (constant SGD)
simulates a Markov chain with a stationary distribution. With this perspective,
we derive several new results. (1) We show that constant SGD can be used as an
approximate Bayesian posterior inference algorithm. Specifically, we show how
to adjust ... | 1704.04289v2 |
2017-05-19 | Phenomenology of light- and strange-quark simultaneous production at high energies | This letter presents an extension of EPL116(2017)62001 to light- and
strange-quark nonequilibrium chemical phase-space occupancy factors
($\gamma_{q,s}$). The resulting damped trigonometric functionalities relating
$\gamma_{q,s}$ to the nucleon-nucleon center-of-mass energies $(\sqrt{s_{NN}})$
looks very similar except... | 1705.06961v1 |
2017-11-08 | An Extended Kalman Filter Enhanced Hilbert-Huang Transform in Oscillation Detection | Hilbert-Huang transform (HHT) has drawn great attention in power system
analysis due to its capability to deal with dynamic signal and provide
instantaneous characteristics such as frequency, damping, and amplitudes.
However, its shortcomings, including mode mixing and end effects, are as
significant as its advantages.... | 1711.04644v1 |
2017-11-15 | Probing Split-Ring Resonator Permeabilities with Loop-Gap Resonators | A method is proposed to experimentally determine the effective complex
permeability of split-ring resonator (SRR) arrays used in the design of
metamaterials at microwave frequencies. We analyze the microwave response of a
loop-gap resonator (LGR) whose bore has been partially loaded with one or more
SRRs. Our analysis ... | 1711.05819v1 |
2017-12-01 | Some Optimizations on Detecting Gravitational Wave Using Convolutional Neural Network | This work investigates the problem of detecting gravitational wave (GW)
events based on simulated damped sinusoid signals contaminated with white
Gaussian noise. It is treated as a classification problem with one class for
the interesting events. The proposed scheme consists of the following two
successive steps: decom... | 1712.00356v2 |
2018-02-12 | Dynamics of a magnetic skyrmionium driven by spin waves | The magnetic skyrmionium is a skyrmion-like structure but carries a zero net
skyrmion number, which can be used as a building block for non-volatile
information processing devices. Here, we study the dynamics of a magnetic
skyrmionium driven by propagating spin waves. It is found that the skyrmionium
can be effectively... | 1802.03868v2 |
2018-02-16 | Articulatory information and Multiview Features for Large Vocabulary Continuous Speech Recognition | This paper explores the use of multi-view features and their discriminative
transforms in a convolutional deep neural network (CNN) architecture for a
continuous large vocabulary speech recognition task. Mel-filterbank energies
and perceptually motivated forced damped oscillator coefficient (DOC) features
are used afte... | 1802.05853v1 |
2018-02-26 | A magnetic resonance in high-frequency viscosity of two-dimensional electrons | Two-dimensional (2D) electrons in high-quality nanostructures at low
temperatures can form a viscous fluid. We develop a theory of high-frequency
magnetotransport in such fluid. The time dispersion of viscosity should be
taken into account at the frequencies about and above the rate of
electron-electron collisions. We ... | 1802.09179v3 |
2018-03-14 | Langevin equation in systems with also negative temperatures | We discuss how to derive a Langevin equation (LE) in non standard systems,
i.e. when the kinetic part of the Hamiltonian is not the usual quadratic
function. This generalization allows to consider also cases with negative
absolute temperature. We first give some phenomenological arguments suggesting
the shape of the vi... | 1803.05317v2 |
2018-04-07 | Chemotaxis effect vs logistic damping on boundedness in the 2-D minimal Keller-Segel model | In this paper, we study chemotaxis effect vs logistic dampening on
boundedness for the two-dimensional minimal Keller-Segel model with logistic
source in a 2-D smooth and bounded domain. It is well-known that this model
allows only for global and uniform-in-time bounded solutions for any
chemotactic strength and logist... | 1804.02501v1 |
2018-05-07 | Lewis-Riesenfeld quantization and SU(1,1) coherent states for 2D damped harmonic oscillator | In this paper we study a two-dimensional [2D] rotationally symmetric harmonic
oscillator with time-dependent frictional force. At the classical level, we
solve the equations of motion for a particular case of the time-dependent
coefficient of friction. At the quantum level, we use the Lewis-Riesenfeld
procedure of inva... | 1805.02484v2 |
2018-05-16 | Numerical analysis of the weakly nonlinear Boussinesq system with a freely moving body on the bottom | In this study, the numerical analysis of a specific fluid-solid interaction
problem is detailed. The weakly nonlinear Boussinesq system is considered with
the addition of a solid object lying on the flat bottom, allowed to move
horizontally under the pressure forces created by the waves. We present an
accurate finite d... | 1805.07216v1 |
2018-05-21 | Squeezed in three dimensions, moving in two: Hydrodynamic theory of 3D incompressible easy-plane polar active fluids | We study the hydrodynamic behavior of three dimensional (3D) incompressible
collections of self-propelled entities in contact with a momentum sink in a
state with non-zero average velocity, hereafter called 3D easy-plane
incompressible polar active fluids. We show that the hydrodynamic model for
this system belongs to ... | 1805.07930v1 |
2018-06-12 | Complex magnetism and non-Fermi liquid state in the vicinity of the quantum critical point in the CeCo$_{1-x}$Fe$_x$Ge$_3$ series | We report extensive studies on the CeCo$_{1-x}$Fe$_{x}$Ge$_3$ alloys, which
show quantum critical point (QCP) due to damping the antiferromagnetic order in
CeCoGe$_3$ down to 0 K by doping with the paramagnetic CeFeGe$_3$ compound. The
presence of QCP is confirmed by detecting the non-Fermi liquid behavior (NFL)
using ... | 1806.04656v1 |
2018-08-21 | Position Sensor-less and Adaptive Speed Design for Controlling Brush-less DC Motor Drives | This paper proposes a method for direct torque control of Brushless DC (BLDC)
motors. Evaluating the trapezium of back-EMF is needed, and is done via a
sliding mode observer employing just one measurement of stator current. The
effect of the proposed estimation algorithm is reducing the impact of switching
noise and co... | 1808.06768v1 |
2018-09-28 | Unifying averaged dynamics of the Fokker-Planck equation for Paul traps | Collective dynamics of a collisional plasma in a Paul trap is governed by the
Fokker-Planck equation, which is usually assumed to lead to a unique asymptotic
time-periodic solution irrespective of the initial plasma distribution. This
uniqueness is, however, hard to prove in general due to analytical
difficulties. For ... | 1809.10952v2 |
2018-10-29 | Three Mechanisms of Weight Decay Regularization | Weight decay is one of the standard tricks in the neural network toolbox, but
the reasons for its regularization effect are poorly understood, and recent
results have cast doubt on the traditional interpretation in terms of $L_2$
regularization. Literal weight decay has been shown to outperform $L_2$
regularization for... | 1810.12281v1 |
2018-11-05 | Logarithmic estimates for continuity equations | The aim of this short note is twofold. First, we give a sketch of the proof
of a recent result proved by the authors in the paper [Colombo, Crippa, and
Spirito, Calc. Var. Partial Differential Equations 2015] concerning existence
and uniqueness of renormalized solutions of continuity equations with unbounded
damping co... | 1811.02463v1 |
2018-12-20 | Edge modes and Fabry-Perot Plasmonic Resonances in anomalous-Hall Thin Films | We study plasmon propagation on a metallic two-dimensional surface partially
coated with a thin film of anomalous-Hall material. The resulting three
regions, separated by two sharp interfaces, are characterised by different Hall
conductivities but identical normal conductivities. A single bound mode is
found, which can... | 1812.08798v2 |
2019-01-01 | Gravitational Waves in the Presence of Viscosity | We analyze gravitational waves propagating in an isotropic cosmic fluid
endowed with a bulk viscosity $\zeta$ and a shear viscosity $\eta$, assuming
these coefficients to vary with fluid density $\rho$ as $\rho^\lambda$, with
$\lambda=1/2$ favored by experimental evidence. We give the general governing
equation for the... | 1901.00767v3 |
2019-01-20 | Fate of spin polarization in a relativistic fluid: An entropy-current analysis | We derive relativistic hydrodynamic equations with a dynamical spin degree of
freedom on the basis of an entropy-current analysis. The first and second laws
of local thermodynamics constrain possible structures of the constitutive
relations including a spin current and the antisymmetric part of the
(canonical) energy-m... | 1901.06615v2 |
2019-01-24 | A priori error estimates for the finite element approximation of Westervelt's quasilinear acoustic wave equation | We study the spatial discretization of Westervelt's quasilinear strongly
damped wave equation by piecewise linear finite elements. Our approach employs
the Banach fixed-point theorem combined with a priori analysis of a linear wave
model with variable coefficients. Degeneracy of the semi-discrete Westervelt
equation is... | 1901.08510v3 |
2019-02-26 | Coulomb drag of excitons in Bose-Fermi mixtures | We develop a microscopic theory of the Coulomb drag effect in a hybrid system
consisting of spatially separated two-dimensional quantum gases of degenerate
electrons and dipolar excitons. We consider both the normal-phase and
condensate regimes of the exciton subsystem and investigate the cross-mobility
of the system b... | 1902.09721v1 |
2019-04-23 | Generalized Moment Correction for Long-Ranged Electrostatics | Describing long-ranged electrostatics using short-ranged pair potentials is
appealing since the computational complexity scales linearly with the number of
particles. The foundation of this approach is to mimic the long-ranged medium
response by cancelling electric multipoles within a small cutoff sphere. We
propose a ... | 1904.10335v2 |
2019-06-02 | Analytical prediction of logarithmic Rayleigh scattering in amorphous solids from tensorial heterogeneous elasticity with power-law disorder | The damping or attenuation coefficient of sound waves in solids due to
impurities scales with the wavevector to the fourth power, also known as
Rayleigh scattering. In amorphous solids, Rayleigh scattering may be enhanced
by a logarithmic factor although computer simulations offer conflicting
conclusions regarding this... | 1906.00372v3 |
2019-05-31 | Deterministic and stochastic damage detection via dynamic response analysis | The paper proposes a method of damage detection in elastic materials, which
is based on analyzing the time-dependent (dynamic) response of the material
excited by an acoustic signal. A case study is presented consisting of
experimental measurements and their mathematical analysis. The decisive
parameters (wave speed an... | 1906.00797v2 |
2019-07-21 | Supersolutions for parabolic equations with unbounded diffusion and its applications to some classes of parabolic and hyperbolic equations | This paper is concerned with supersolutions to parabolic equations of the
form \begin{equation} \partial_t U (x,t)-D(x)\Delta U(x,t)=0, \quad (x,t)\in
\mathbb{R}^N \times (0,\infty), \end{equation} where $D\in C(\mathbb{R}^N)$ is
positive. Under the behavior of the diffusion coefficient $D$ with polynomial
order at spa... | 1907.08992v1 |
2019-08-11 | A computational study of transient shear banding in soft jammed solids | We have designed 3D numerical simulations of a soft spheres model, with size
polidispersity and in athermal conditions, to study the transient shear banding
that occurs during yielding of jammed soft solids. We analyze the effects of
different types of drag coefficients used in the simulations and compare the
results o... | 1908.03943v1 |
2019-09-10 | Diffusion and memory effect in a stochastic processes and the correspondence to an information propagation in a social system | A generalized Langevin equation is suggested to describe a system with
memory($u(t,t') = \frac{1}{\Gamma (\nu )}(t - t')^\nu $) as well as with
positive and negative damping. The equation can be transformed into the
Fokker-Planck equation by using the Kramers-Moyal expansion. The solution of
Fokker-Planck equation show... | 1909.04220v1 |
2019-10-10 | Mesoscopic theory for systems with competing interactions near a confining wall | Mesoscopic theory for self-assembling systems near a planar confining surface
is developed. Euler- Lagrange (EL) equations and the boundary conditions (BC)
for the local volume fraction and the correlation function are derived from the
DFT expression for the grand thermodynamic potential. Various levels of
approximatio... | 1910.04474v2 |
2019-11-11 | Orbit-like trajectory of the vortex core in a magnetic nanodot | In physics, conserved quantities are key to understanding and describing
physical phenomena. These conserved quantities are related to Noether's theorem
and the Lagrangian description both in classical mechanics and in field theory.
In this article we have found the equation of the vortex core trajectory in
terms of tw... | 1911.04555v2 |
2019-12-04 | A high-order discontinuous Galerkin method for nonlinear sound waves | We propose a high-order discontinuous Galerkin scheme for nonlinear acoustic
waves on polytopic meshes. To model sound propagation with and without losses,
we use Westervelt's nonlinear wave equation with and without strong damping.
Challenges in the numerical analysis lie in handling the nonlinearity in the
model, whi... | 1912.02281v1 |
2019-12-05 | The blow up of solutions to semilinear wave equations on asymptotically Euclidean manifolds | In this paper, we investigate the problem of blow up and sharp upper bound
estimates of the lifespan for the solutions to the semilinear wave equations,
posed on asymptotically Euclidean manifolds. Here the metric is assumed to be
exponential perturbation of the spherical symmetric, long range asymptotically
Euclidean ... | 1912.02540v1 |
2019-12-08 | Dynamical Primal-Dual Accelerated Method with Applications to Network Optimization | This paper develops a continuous-time primal-dual accelerated method with an
increasing damping coefficient for a class of convex optimization problems with
affine equality constraints. This paper analyzes critical values for parameters
in the proposed method and prove that the rate of convergence in terms of the
duali... | 1912.03690v2 |
2020-01-08 | Assessing different approaches to ab initio calculations of spin wave stiffness | Ab initio calculations of the spin wave stiffness constant $D$ for elemental
Fe and Ni performed by different groups in the past have led to values with a
considerable spread of 50-100 %. We present results for the stiffness constant
$D$ of Fe, Ni, and permalloy Fe$_{0.19}$Ni$_{0.81}$ obtained by three different
approa... | 2001.02558v2 |
2020-02-12 | Exact Solution for the Heat Conductance in Harmonic Chains | We present an exact solution for the heat conductance along a harmonic chain
connecting two reservoirs at different temperatures. In this model, the end
points correspond to Brownian particles with different damping coefficients.
Such analytical expression for the heat conductance covers its behavior from
mesoscopic to... | 2002.05195v2 |
2020-04-17 | On Enhanced Dissipation for the Boussinesq Equations | In this article we consider the stability and damping problem for the 2D
Boussinesq equations with partial dissipation near a two parameter family of
stationary solutions which includes Couette flow and hydrostatic balance.
In the first part we show that for the linearized problem in an infinite
periodic channel the ... | 2004.08125v1 |
2020-05-05 | Heavy quark diffusion in an overoccupied gluon plasma | We extract the heavy-quark diffusion coefficient \kappa and the resulting
momentum broadening <p^2> in a far-from-equilibrium non-Abelian plasma. We find
several features in the time dependence of the momentum broadening: a short
initial rapid growth of <p^2>, followed by linear growth with time due to
Langevin-type dy... | 2005.02418v2 |
2020-09-02 | Frustrated bearings | In a bearing state, touching spheres (disks in two dimensions) roll on each
other without slip. Here we frustrate a system of touching spheres by imposing
two different bearing states on opposite sides and search for the
configurations of lowest energy dissipation. If the dissipation between
contacts of spheres is visc... | 2009.01295v1 |
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