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2022-07-14 | The Damped Wave Equation with Acoustic Boundary Conditions and Non-locally Reacting Surfaces | The aim of the paper is to study the problem $$u_{tt}+du_t-c^2\Delta u=0
\qquad \text{in $\mathbb{R}\times\Omega$,}$$ $$\mu v_{tt}- \text{div}_\Gamma
(\sigma \nabla_\Gamma v)+\delta v_t+\kappa v+\rho u_t =0\qquad \text{on
$\mathbb{R}\times \Gamma_1$,}$$ $$v_t =\partial_\nu u\qquad \text{on
$\mathbb{R}\times \Gamma_1$,}... | 2207.07047v2 |
2022-12-07 | Finite-time blow-up to hyperbolic Keller-Segel system of consumption type with logarithmic sensitivity | This paper deals with a hyperbolic Keller-Segel system of consumption type
with the logarithmic sensitivity \begin{equation*}
\partial_{t} \rho = - \chi\nabla \cdot \left (\rho \nabla \log c\right),\quad
\partial_{t} c = - \mu c\rho\quad (\chi,\,\mu>0) \end{equation*} in
$\mathbb{R}^d\; (d \ge1)$ for nonvanishing ini... | 2212.03758v4 |
2023-02-06 | Cosmologically Varying Kinetic Mixing | The portal connecting the invisible and visible sectors is one of the most
natural explanations of the dark world. However, the early-time dark matter
production via the portal faces extremely stringent late-time constraints. To
solve such tension, we construct the scalar-controlled kinetic mixing varying
with the ultr... | 2302.03056v2 |
2023-09-08 | Minimum-dissipation model for large-eddy simulation in OpenFoam -A study on channel flow, periodic hills and flow over cylinder | The minimum-dissipation model is applied to turbulent channel flows up to
$Re_\tau = 2000$, flow past a circular cylinder at $Re=3900$, and flow over
periodic hills at $Re=10595$. Numerical simulations are performed in OpenFOAM
which is based on finite volume methods for discretizing partial differential
equations. We ... | 2309.04415v1 |
2023-11-02 | Minimum-dissipation model for large-eddy simulation using symmetry-preserving discretization in OpenFOAM | The minimum-dissipation model is applied to channel flow up to $Re_\tau =
2000$, flow past a circular cylinder at $Re=3900$, and flow over periodic hills
at $Re=10595$. Numerical simulations were performed in OpenFOAM which is based
on the finite volume methods. We used both symmetry-preserving and standard
second-orde... | 2311.01360v1 |
2024-01-22 | Axions and Primordial Magnetogenesis: the Role of Initial Axion Inhomogeneities | The relic density of dark matter in the $\Lambda$CDM model restricts the
parameter space for a cosmological axion field, constraining the axion decay
constant, the initial amplitude of the axion field and the axion mass. It is
shown via lattice simulations how the relic density of axion-like particles
with masses close... | 2401.11822v1 |
2024-01-28 | Perturbation of parabolic equations with time-dependent linear operators: convergence of linear processes and solutions | In this work we consider parabolic equations of the form \[
(u_{\varepsilon})_t +A_{\varepsilon}(t)u_{{\varepsilon}} = F_{\varepsilon}
(t,u_{{\varepsilon} }), \] where $\varepsilon$ is a parameter in
$[0,\varepsilon_0)$ and $\{A_{\varepsilon}(t), \ t\in \mathbb{R}\}$ is a family
of uniformly sectorial operators. As $\v... | 2401.15799v1 |
1999-11-24 | Damped Lyman alpha absorber and the faint end of the galaxy luminosity function at high redshift | We combine predictions for several hierarchical cosmogonies with
observational evidence on damped Lyman alpha systems to establish a
correspondence between the high redshift galaxy population and the properties
of damped Lyman alpha systems. We assume that high redshift galaxies and damped
Lyman alpha systems are hoste... | 9911447v1 |
2003-03-13 | An explicit unconditionally stable numerical method for solving damped nonlinear Schrödinger equations with a focusing nonlinearity | This paper introduces an extension of the time-splitting sine-spectral (TSSP)
method for solving damped focusing nonlinear Schr\"{o}dinger equations (NLS).
The method is explicit, unconditionally stable and time transversal invariant.
Moreover, it preserves the exact decay rate for the normalization of the wave
functio... | 0303158v1 |
2004-11-03 | Quantum probability applied to the damped harmonic oscillator | In this introductory course we sketch the framework of quantum probability in
order to discuss open quantum systems, in particular the damped harmonic
oscillator. | 0411024v1 |
2006-11-23 | Path integrals and wavepacket evolution for damped mechanical systems | Damped mechanical systems with various forms of damping are quantized using
the path integral formalism. In particular, we obtain the path integral kernel
for the linearly damped harmonic oscillator and a particle in a uniform
gravitational field with linearly or quadratically damped motion. In each case,
we study the ... | 0611239v1 |
2007-07-05 | Damping of bulk excitations over an elongated BEC - the role of radial modes | We report the measurement of Beliaev damping of bulk excitations in cigar
shaped Bose Einstein condensates of atomic vapor. By using post selection,
excitation line shapes of the total population are compared with those of the
undamped excitations. We find that the damping depends on the initial
excitation energy of th... | 0707.0776v1 |
2008-09-22 | Damping in 2D and 3D dilute Bose gases | Damping in 2D and 3D dilute gases is investigated using both the
hydrodynamical approach and the Hartree-Fock-Bogoliubov (HFB) approximation .
We found that the both methods are good for the Beliaev damping at zero
temperature and Landau damping at very low temperature, however, at high
temperature, the hydrodynamical ... | 0809.3632v3 |
2008-12-08 | Landau Damping and Alfven Eigenmodes of Neutron Star Torsion Oscillations | Torsion oscillations of the neutron star crust are Landau damped by the
Alfven continuum in the bulk. For strong magnetic fields (in magnetars),
undamped Alfven eigenmodes appear. | 0812.1570v1 |
2010-09-24 | Spatial Damping of Propagating Kink Waves in Prominence Threads | Transverse oscillations and propagating waves are frequently observed in
threads of solar prominences/filaments and have been interpreted as kink
magnetohydrodynamic (MHD) modes. We investigate the spatial damping of
propagating kink MHD waves in transversely nonuniform and partially ionized
prominence threads. Resonan... | 1009.4871v1 |
2012-08-27 | Optimization of the damped quantum search | The damped quantum search proposed in [A. Mizel, Phys. Rev. Lett., 102 150501
(2009)] was analyzed by calculating the highest possible probability of finding
the target state in each iteration. A new damping parameter that depends on the
number of iterations was obtained, this was compared to the critical damping
param... | 1208.5475v1 |
2013-04-03 | Damping the zero-point energy of a harmonic oscillator | The physics of quantum electromagnetism in an absorbing medium is that of a
field of damped harmonic oscillators. Yet until recently the damped harmonic
oscillator was not treated with the same kind of formalism used to describe
quantum electrodynamics in a arbitrary medium. Here we use the techniques of
macroscopic QE... | 1304.0977v2 |
2015-05-28 | Damping factors for head-tail modes at strong space charge | This paper suggests how feedback and Landau damping can be taken into account
for transverse oscillations of bunched beam at strong space charge. | 1505.07704v1 |
2015-06-18 | Damping of MHD turbulence in partially ionized plasma: implications for cosmic ray propagation | We study the damping from neutral-ion collisions of both incompressible and
compressible magnetohydrodynamic (MHD) turbulence in partially ionized medium.
We start from the linear analysis of MHD waves applying both single-fluid and
two-fluid treatments. The damping rates derived from the linear analysis are
then used ... | 1506.05585v1 |
2016-02-04 | Damping Evaluation for Free Vibration of Spherical Structures in Elastodynamic-Acoustic Interaction | This paper discusses the free vibration of elastic spherical structures in
the presence of an externally unbounded acoustic medium. In this vibration,
damping associated with the radiation of energy from the confined solid medium
to the surrounding acoustic medium is observed. Evaluating the coupled system
response (so... | 1604.06738v1 |
2017-01-10 | Magnetic properties in ultra-thin 3d transition metal alloys II: Experimental verification of quantitative theories of damping and spin-pumping | A systematic experimental study of Gilbert damping is performed via
ferromagnetic resonance for the disordered crystalline binary 3d transition
metal alloys Ni-Co, Ni-Fe and Co-Fe over the full range of alloy compositions.
After accounting for inhomogeneous linewidth broadening, the damping shows
clear evidence of both... | 1701.02475v1 |
2017-06-14 | Temperature-dependent Gilbert damping of Co2FeAl thin films with different degree of atomic order | Half-metallicity and low magnetic damping are perpetually sought for in
spintronics materials and full Heusler alloys in this respect provide
outstanding properties. However, it is challenging to obtain the well-ordered
half-metallic phase in as-deposited full Heusler alloys thin films and theory
has struggled to estab... | 1706.04670v2 |
2017-09-05 | Enhancement of space-charge induced damping due to reactive impedances for head-tail modes | Landau damping of head-tail modes in bunches due to spreads in the tune shift
can be a deciding factor for beam stability. We demonstrate that the coherent
tune shifts due to reactive impedances can enhance the space-charge induced
damping and change the stability thresholds (here, a reactive impedance implies
the imag... | 1709.01425v1 |
2018-05-21 | Critical damping in nonviscously damped linear systems | In structural dynamics, energy dissipative mechanisms with non-viscous
damping are characterized by their dependence on the time-history of the
response velocity, mathematically represented by convolution integrals
involving hereditary functions. Combination of damping parameters in the
dissipative model can lead the s... | 1805.08022v1 |
2018-11-01 | Hereditary effects of exponentially damped oscillators with past histories | Hereditary effects of exponentially damped oscillators with past histories
are considered in this paper. Nonviscously damped oscillators involve
hereditary damping forces which depend on time-histories of vibrating motions
via convolution integrals over exponentially decaying functions. As a result,
this kind of oscill... | 1811.00216v1 |
2019-02-22 | Strongly Enhanced Gilbert Damping in 3d Transition Metal Ferromagnet Monolayers in Contact with Topological Insulator Bi2Se3 | Engineering Gilbert damping of ferromagnetic metal films is of great
importance to exploit and design spintronic devices that are operated with an
ultrahigh speed. Based on scattering theory of Gilbert damping, we extend the
torque method originally used in studies of magnetocrystalline anisotropy to
theoretically dete... | 1902.08700v1 |
2019-07-01 | Magnon decay theory of Gilbert damping in metallic antiferromagnets | Gilbert damping is a key property governing magnetization dynamics in ordered
magnets. We present a theoretical study of intrinsic Gilbert damping induced by
magnon decay in antiferromagnetic metals through $s$-$d$ exchange interaction.
Our theory delineates the qualitative features of damping in metallic
antiferromagn... | 1907.01045v1 |
2019-08-01 | The Temperature-dependent Damping of Propagating Slow Magnetoacoustic Waves | The rapid damping of slow magnetoacoustic waves in the solar corona has been
extensively studied in previous years. Most studies suggest that thermal
conduction is a dominant contributor to this damping, albeit with a few
exceptions. Employing extreme-ultraviolet (EUV) imaging data from SDO/AIA, we
measure the damping ... | 1908.00384v1 |
2019-10-14 | Decay rates for the damped wave equation with finite regularity damping | Decay rates for the energy of solutions of the damped wave equation on the
torus are studied. In particular, damping invariant in one direction and equal
to a sum of squares of nonnegative functions with a particular number of
derivatives of regularity is considered. For such damping energy decays at rate
$1/t^{2/3}$. ... | 1910.06372v3 |
2022-07-01 | Seismic Response of Yielding Structures Coupled to Rocking Walls with Supplemental Damping | Given that the coupling of a framing structure to a strong, rocking wall
enforces a first-mode response, this paper investigates the dynamic response of
a yielding single-degree-of-freedom oscillator coupled to a rocking wall with
supplemental damping (hysteretic or linear viscous) along its sides. The full
nonlinear e... | 2207.00641v1 |
2022-11-24 | Influence of non-local damping on magnon properties of ferromagnets | We study the influence of non-local damping on magnon properties of Fe, Co,
Ni and Fe$_{1-x}$Co$_{x}$ ($x=30\%,50\%$) alloys. The Gilbert damping parameter
is typically considered as a local scalar both in experiment and in theoretical
modelling. However, recent works have revealed that Gilbert damping is a
non-local q... | 2211.13486v1 |
2023-03-08 | Material-Geometry Interplay in Damping of Biomimetic Scale Beams | Biomimetic scale-covered substrates are architected meta-structures
exhibiting fascinating emergent nonlinearities via the geometry of collective
scales contacts. In spite of much progress in understanding their elastic
nonlinearity, their dissipative behavior arising from scales sliding is
relatively uninvestigated in... | 2303.04920v1 |
2009-04-30 | Wavelength Accuracy of the Keck HIRES Spectrograph and Measuring Changes in the Fine Structure Constant | We report on an attempt to accurately wavelength calibrate four nights of
data taken with the Keck HIRES spectrograph on QSO PHL957, for the purpose of
determining whether the fine structure constant was different in the past.
Using new software and techniques, we measured the redshifts of various Ni II,
Fe II, Si II, ... | 0904.4725v2 |
2017-12-11 | Self-acceleration in scalar-bimetric theories | We describe scalar-bimetric theories where the dynamics of the Universe are
governed by two separate metrics, each with an Einstein-Hilbert term. In this
setting, the baryonic and dark matter components of the Universe couple to
metrics which are constructed as functions of these two gravitational metrics.
The scalar f... | 1712.04520v2 |
1998-03-28 | Landau damping and the echo effect in a confined Bose-Einstein condensate | Low energy collective mode of a confined Bose-Einstein condensate should
demonstrate the echo effect in the regime of Landau damping. This echo is a
signature of reversible nature of Landau damping. General expression for the
echo profile is derived in the limit of small amplitudes of the external
pulses. Several unive... | 9803351v1 |
2000-07-10 | Dephasing of Electrons on Helium by Collisions with Gas Atoms | The damping of quantum effects in the transport properties of electrons
deposited on a surface of liquid helium is studied. It is found that due to
vertical motion of the helium vapour atoms the interference of paths of
duration $t$ is damped by a factor $\exp - (t/\tau_v)^3$. An expression is
derived for the weak-loca... | 0007160v1 |
1997-10-07 | Damping rate of plasmons and photons in a degenerate nonrelativistic plasma | A calculation is presented of the plasmon and photon damping rates in a dense
nonrelativistic plasma at zero temperature, following the resummation program
of Braaten-Pisarski. At small soft momentum $k$, the damping is dominated by $3
\to 2$ scattering processes corresponding to double longitudinal Landau
damping. The... | 9710260v1 |
2002-12-16 | Influence of damping on the vanishing of the electro-optic effect in chiral isotropic media | Using first principles, it is demonstrated that radiative damping alone
cannot lead to a nonvanishing electro-optic effect in a chiral isotropic
medium. This conclusion is in contrast with that obtained by a calculation in
which damping effects are included using the standard phenomenological model.
We show that these ... | 0212089v1 |
2005-08-28 | Simultaneous amplitude and phase damping of a kind of Gaussian states and their separability | We give out the time evolution solution of simultaneous amplitude and phase
damping for any continuous variable state. For the simultaneous amplitude and
phase damping of a wide class of two- mode entangled Gaussian states, two
analytical conditions of the separability are given. One is the sufficient
condition of sepa... | 0508209v2 |
2007-08-28 | Ising Dynamics with Damping | We show for the Ising model that is possible construct a discrete time
stochastic model analogous to the Langevin equation that incorporates an
arbitrary amount of damping. It is shown to give the correct equilibrium
statistics and is then used to investigate nonequilibrium phenomena, in
particular, magnetic avalanches... | 0708.3855v1 |
2008-02-08 | On the scaling of the damping time for resonantly damped oscillations in coronal loops | There is not as yet full agreement on the mechanism that causes the rapid
damping of the oscillations observed by TRACE in coronal loops. It has been
suggested that the variation of the observed values of the damping time as
function of the corresponding observed values of the period contains
information on the possibl... | 0802.1143v1 |
2008-10-02 | Critically damped quantum search | Although measurement and unitary processes can accomplish any quantum
evolution in principle, thinking in terms of dissipation and damping can be
powerful. We propose a modification of Grover's algorithm in which the idea of
damping plays a natural role. Remarkably, we have found that there is a
critical damping value ... | 0810.0470v1 |
2009-07-01 | Modal approximations to damped linear systems | We consider a finite dimensional damped second order system and obtain
spectral inclusion theorems for the related quadratic eigenvalue problem. The
inclusion sets are the 'quasi Cassini ovals' which may greatly outperform
standard Gershgorin circles. As the unperturbed system we take a modally damped
part of the syste... | 0907.0167v1 |
2010-01-14 | Multi-Error-Correcting Amplitude Damping Codes | We construct new families of multi-error-correcting quantum codes for the
amplitude damping channel. Our key observation is that, with proper encoding,
two uses of the amplitude damping channel simulate a quantum erasure channel.
This allows us to use concatenated codes with quantum erasure-correcting codes
as outer co... | 1001.2356v1 |
2011-09-05 | Spectral theory of damped quantum chaotic systems | We investigate the spectral distribution of the damped wave equation on a
compact Riemannian manifold, especially in the case of a metric of negative
curvature, for which the geodesic flow is Anosov. The main application is to
obtain conditions (in terms of the geodesic flow on $X$ and the damping
function) for which t... | 1109.0930v1 |
2012-06-07 | From resolvent estimates to damped waves | In this paper we show how to obtain decay estimates for the damped wave
equation on a compact manifold without geometric control via knowledge of the
dynamics near the un-damped set. We show that if replacing the damping term
with a higher-order \emph{complex absorbing potential} gives an operator
enjoying polynomial r... | 1206.1565v1 |
2012-12-03 | Inviscid limit of stochastic damped 2D Navier-Stokes equations | We consider the inviscid limit of the stochastic damped 2D Navier- Stokes
equations. We prove that, when the viscosity vanishes, the stationary solution
of the stochastic damped Navier-Stokes equations converges to a stationary
solution of the stochastic damped Euler equation and that the rate of
dissipation of enstrop... | 1212.0509v3 |
2014-01-13 | NLSE for quantum plasmas with the radiation damping | We consider contribution of the radiation damping in the quantum hydrodynamic
equations for spinless particles. We discuss possibility of obtaining of
corresponding non-linear Schrodinger equation (NLSE) for the macroscopic wave
function. We compare contribution of the radiation damping with weakly (or
semi-) relativis... | 1401.2829v1 |
2014-09-26 | An ultimate storage ring lattice with vertical emittance generated by damping wigglers | We discuss the approach of generating round beams for ultimate storage rings
using vertical damping wigglers (with horizontal magnetic field). The vertical
damping wigglers provide damping and excite vertical emittance. This eliminates
the need to generate large linear coupling that is impractical with traditional
off-... | 1409.7452v2 |
2016-08-14 | Mechanical energy and mean equivalent viscous damping for SDOF fractional oscillators | This paper addresses the total mechanical energy of a single degree of
freedom fractional oscillator. Based on the energy storage and dissipation
properties of the Caputo fractional derivatives, the expression for total
mechanical energy in the single degree of freedom fractional oscillator is
firstly presented. The en... | 1608.04071v1 |
2017-03-01 | Behaviors of the energy of solutions of two coupled wave equations with nonlinear damping on a compact manifold with boundary | In this paper we study the behaviors of the the energy of solutions of
coupled wave equations on a compact manifold with boundary in the case of
indirect nonlinear damping . Only one of the two equations is directly damped
by a localized nonlinear damping term. Under geometric conditions on both the
coupling and the da... | 1703.00172v1 |
2017-06-02 | Vanishing viscosity limit for global attractors for the damped Navier--Stokes system with stress free boundary conditions | We consider the damped and driven Navier--Stokes system with stress free
boundary conditions and the damped Euler system in a bounded domain
$\Omega\subset\mathbf{R}^2$. We show that the damped Euler system has a
(strong) global attractor in~$H^1(\Omega)$. We also show that in the vanishing
viscosity limit the global a... | 1706.00607v1 |
2018-01-20 | Long time dynamics for weakly damped nonlinear Klein-Gordon equations | We continue our study of damped nonlinear Klein-Gordon equations. In our
previous work we considered fixed positive damping and proved a form of the
soliton resolution conjecture for radial solutions. In contrast, here we
consider damping which decreases in time to 0. In the class of radial data we
again establish soli... | 1801.06735v1 |
2018-02-28 | Nonexistence of global solutions of wave equations with weak time-dependent damping and combined nonlinearity | In our previous two works, we studied the blow-up and lifespan estimates for
damped wave equations with a power nonlinearity of the solution or its
derivative, with scattering damping independently. In this work, we are devoted
to establishing a similar result for a combined nonlinearity. Comparing to the
result of wav... | 1802.10273v1 |
2018-11-12 | Choking non-local magnetic damping in exchange biased ferromagnets | We investigated the temperature dependence of the magnetic damping in the
exchange biased Pt/ Fe50Mn50 /Fe20Ni80 /SiOx multilayers. In samples having a
strong exchange bias, we observed a drastic decrease of the magnetic damping of
the FeNi with increasing temperature up to the blocking temperature. The
results essenti... | 1811.04821v1 |
2019-05-23 | Escaping Locally Optimal Decentralized Control Polices via Damping | We study the evolution of locally optimal decentralized controllers with the
damping of the control system. Empirically it is shown that even for instances
with an exponential number of connected components, damping merges all local
solutions to the one global solution. We characterize the evolution of locally
optimal ... | 1905.09915v1 |
2019-08-22 | Some remarks on the asymptotic profile of solutions to structurally damped $σ$-evolution equations | In this paper, we are interested in analyzing the asymptotic profiles of
solutions to the Cauchy problem for linear structurally damped
$\sigma$-evolution equations in $L^2$-sense. Depending on the parameters
$\sigma$ and $\delta$ we would like to not only indicate approximation formula
of solutions but also recognize ... | 1908.08492v1 |
2019-09-18 | Global smooth solutions of the damped Boussinesq equations with a class of large initial data | The global regularity problem concerning the inviscid Boussinesq equations
remains an open problem. In an attempt to understand this problem, we examine
the damped Boussinesq equations and study how damping affects the regularity of
solutions. In this paper, we consider the global existence to the damped
Boussinesq equ... | 1909.08360v1 |
2020-02-15 | Asymptotic profile and optimal decay of solutions of some wave equations with logarithmic damping | We introduce a new model of the nonlocal wave equations with a logarithmic
damping mechanism. We consider the Cauchy poroblem for the new model in the
whole space. We study the asymptotic profile and optimal decay and blowup rates
of solutions as time goes to infinity. The damping terms considered in this
paper is not ... | 2002.06319v1 |
2020-05-13 | Weak Input to state estimates for 2D damped wave equations with localized and non-linear damping | In this paper, we study input-to-state (ISS) issues for damped wave equations
with Dirichlet boundary conditions on a bounded domain of dimension two. The
damping term is assumed to be non-linear and localized to an open subset of the
domain. In a first step, we handle the undisturbed case as an extension of a
previous... | 2005.06206v3 |
2020-07-25 | Decay for the Kelvin-Voigt damped wave equation: Piecewise smooth damping | We study the energy decay rate of the Kelvin-Voigt damped wave equation with
piecewise smooth damping on the multi-dimensional domain. Under suitable
geometric assumptions on the support of the damping, we obtain the optimal
polynomial decay rate which turns out to be different from the one-dimensional
case studied in ... | 2007.12994v2 |
2020-08-12 | From Lieb-Thirring inequalities to spectral enclosures for the damped wave equation | Using a correspondence between the spectrum of the damped wave equation and
non-self-adjoint Schroedinger operators, we derive various bounds on complex
eigenvalues of the former. In particular, we establish a sharp result that the
one-dimensional damped wave operator is similar to the undamped one provided
that the L^... | 2008.05176v1 |
2021-08-02 | Wide-Area Damping Control for Interarea Oscillations in Power Grids Based on PMU Measurements | In this paper, a phasor measurement unit (PMU)-based wide-area damping
control method is proposed to damp the interarea oscillations that threaten the
modern power system stability and security. Utilizing the synchronized PMU
data, the proposed almost model-free approach can achieve an effective damping
for the selecte... | 2108.01193v1 |
2021-09-05 | Regularity of the semigroups associated with some damped coupled elastic systems II: a nondegenerate fractional damping case | In this paper, we examine regularity issues for two damped abstract elastic
systems; the damping and coupling involve fractional powers $\mu, \theta$, with
$0 \leq \mu , \theta \leq 1$, of the principal operators. The matrix defining
the coupling and damping is nondegenerate. This new work is a sequel to the
degenerate... | 2109.02044v1 |
2021-09-28 | A robust and efficient line search for self-consistent field iterations | We propose a novel adaptive damping algorithm for the self-consistent field
(SCF) iterations of Kohn-Sham density-functional theory, using a backtracking
line search to automatically adjust the damping in each SCF step. This line
search is based on a theoretically sound, accurate and inexpensive model for
the energy as... | 2109.14018v3 |
2021-11-17 | Spectral asymptotics for the vectorial damped wave equation | The eigenfrequencies associated to a scalar damped wave equation are known to
belong to a band parallel to the real axis. In [Sj{\"o}00] J. Sj{\"o}strand
showed that up to a set of density 0, the eigenfrequencies are confined in a
thinner band determined by the Birkhoff limits of the damping term. In this
article we sh... | 2111.08982v1 |
2021-12-13 | Rotons and their damping in elongated dipolar Bose-Einstein condensates | We discuss finite temperature damping of rotons in elongated Bose-condensed
dipolar gases, which are in the Thomas-Fermi regime in the tightly confined
directions. The presence of many branches of excitations which can participate
in the damping process, is crucial for the Landau damping and results in
significant incr... | 2112.06835v2 |
2022-03-03 | Stability results of locally coupled wave equations with local Kelvin-Voigt damping: Cases when the supports of damping and coupling coefficients are disjoint | In this paper, we study the direct/indirect stability of locally coupled wave
equations with local Kelvin-Voigt dampings/damping and by assuming that the
supports of the dampings and the coupling coefficients are disjoint. First, we
prove the well-posedness, strong stability, and polynomial stability for some
one dimen... | 2203.01632v1 |
2022-03-12 | Asymptotic expansion of solutions to the wave equation with space-dependent damping | We study the large time behavior of solutions to the wave equation with
space-dependent damping in an exterior domain. We show that if the damping is
effective, then the solution is asymptotically expanded in terms of solutions
of corresponding parabolic equations. The main idea to obtain the asymptotic
expansion is th... | 2203.06360v1 |
2022-10-27 | Sharp polynomial decay for polynomially singular damping on the torus | We study energy decay rates for the damped wave equation with unbounded
damping, without the geometric control condition. Our main decay result is
sharp polynomial energy decay for polynomially controlled singular damping on
the torus. We also prove that for normally $L^p$-damping on compact manifolds,
the Schr\"odinge... | 2210.15697v3 |
2023-09-26 | Qualitative properties of solutions to a nonlinear transmission problem for an elastic Bresse beam | We consider a nonlinear transmission problem for a Bresse beam, which
consists of two parts, damped and undamped. The mechanical damping in the
damped part is present in the shear angle equation only, and the damped part
may be of arbitrary positive length. We prove well-posedness of the
corresponding PDE system in ene... | 2309.15171v2 |
2023-09-27 | Dispersion and damping of ion-acoustic waves in the plasma with a regularized kappa-distribution | The dispersion and damping of ion-acoustic waves in the plasma with a
regularized kappa-distribution are studied. The generalized dispersion relation
and damping rate are derived, which both depend significantly on the parameters
alpha and kappa. The numerical analyses show that the wave frequency and the
damping rate ... | 2309.15885v1 |
2023-11-16 | Near-optimal Closed-loop Method via Lyapunov Damping for Convex Optimization | We introduce an autonomous system with closed-loop damping for first-order
convex optimization. While, to this day, optimal rates of convergence are only
achieved by non-autonomous methods via open-loop damping (e.g., Nesterov's
algorithm), we show that our system is the first one featuring a closed-loop
damping while ... | 2311.10053v1 |
2024-02-05 | Fractional damping induces resonant behavior in the Duffing oscillator | The interaction between the fractional order parameter and the damping
parameter can play a relevant role for introducing different dynamical
behaviors in a physical system. Here, we study the Duffing oscillator with a
fractional damping term. Our findings show that for certain values of the
fractional order parameter,... | 2402.02940v1 |
2024-03-13 | Impact of Decoherence on Average Correlation | This article presents a comprehensive study of the impact of decoherence on
the average correlation for pure quantum states. We explore two primary
mechanisms of decoherence: phase damping and amplitude damping, each having
distinct effects on quantum systems. Phase damping, which describes the loss of
quantum coherenc... | 2403.10551v1 |
2001-10-29 | Kinetic equilibrium of iron in the atmospheres of cool dwarf stars II. Weak Fe I lines in the solar spectrum | NLTE line formation calculations of FeI in the solar atmosphere are extended
to include weak optical lines. Previously established atomic models are used to
discriminate between different ways of treating collisional interaction
processes. To derive a common solar FeI abundance from both strong and weak
lines, fine-tun... | 0110605v1 |
2003-11-05 | Are rotating strange quark stars good sources of gravitational waves? | We study the viscosity driven (Jacobi-like) bar mode instability of rapidly
rotating strange stars in general relativity. A triaxial, "bar shaped" compact
star could be an efficient source of continuous wave gravitational radiation in
the frequency range of the forthcoming interferometric detectors. We locate the
secul... | 0311128v1 |
2003-11-24 | Sulphur and zinc abundances in Galactic stars and damped Lyman-alpha systems | High resolution spectra of 34 halo population dwarf and subgiant stars have
been obtained with VLT/UVES and used to derive sulphur abundances from the
8694.0, 8694.6 A and 9212.9, 9237.5 A SI lines. In addition, iron abundances
have been determined from 19 FeII lines and zinc abundances from the 4722.2,
4810.5 ZnI line... | 0311529v1 |
2004-12-13 | Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys | Dislocation velocities and mobilities are studied by Molecular Dynamics
simulations for edge and screw dislocations in pure aluminum and nickel, and
edge dislocations in Al-2.5%Mg and Al-5.0%Mg random substitutional alloys using
EAM potentials. In the pure materials, the velocities of all dislocations are
close to line... | 0412324v1 |
2009-12-28 | Resonant Interactions Between Protons and Oblique Alfvén/Ion-Cyclotron Waves | Resonant interactions between ions and Alfv\'en/ion-cyclotron (A/IC) waves
may play an important role in the heating and acceleration of the fast solar
wind. Although such interactions have been studied extensively for "parallel"
waves, whose wave vectors ${\bf k}$ are aligned with the background magnetic
field ${\bf B... | 0912.5184v1 |
2011-06-14 | The most metal-poor damped Lyman-alpha systems: Insights into chemical evolution in the very metal-poor regime | We present a high spectral resolution survey of the most metal-poor damped
Lyman-alpha absorption systems (DLAs) aimed at probing the nature and
nucleosynthesis of the earliest generations of stars. Our survey comprises 22
systems with iron abundance less than 1/100 solar; observations of seven of
these are reported he... | 1106.2805v2 |
2012-07-24 | Doppler Signatures of the Atmospheric Circulation on Hot Jupiters | The meteorology of hot Jupiters has been characterized primarily with thermal
measurements, but recent observations suggest the possibility of directly
detecting the winds by observing the Doppler shift of spectral lines seen
during transit. Motivated by these observations, we show how Doppler
measurements can place po... | 1207.5639v2 |
2013-01-30 | Tickling the CMB damping tail: scrutinizing the tension between the ACT and SPT experiments | The Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) have
recently provided new, very precise measurements of the cosmic microwave
background (CMB) anisotropy damping tail. The values of the cosmological
parameters inferred from these measurements, while broadly consistent with the
expectations of t... | 1301.7343v2 |
2014-12-16 | Role of the basin boundary conditions in gravity wave turbulence | Gravity wave turbulence is studied experimentally in a large wave basin where
irregular waves are generated unidirectionally. The role of the basin boundary
conditions (absorbing or reflecting) and of the forcing properties are
investigated. To that purpose, an absorbing sloping beach opposite to the
wavemaker can be r... | 1412.5144v2 |
2015-02-11 | Exclusive production of heavy charged Higgs boson pairs in the $p p \to p p H^+ H^-$ reaction at the LHC and a future circular collider | We calculate differential cross sections for exclusive production of heavy
charged scalar, weakly interacting particles (charged Higgs bosons, charged
technipions, etc.) via photon-photon exchanges in the $p p \to p p H^+ H^-$
reaction with exact $2 \to 4$ kinematics. We present distributions in
rapidities, transverse ... | 1502.03323v2 |
2015-07-29 | The chemistry of the most metal-rich damped Lyman $α$ systems at z$\sim2$ II. Context with the Local Group | Using our sample of the most metal-rich damped Lyman $\alpha$ systems (DLAs)
at z$\sim2$, and two literature compilations of chemical abundances in 341 DLAs
and 2818 stars, we present an analysis of the chemical composition of DLAs in
the context of the Local Group. The metal-rich sample of DLAs at z$\sim2$
probes meta... | 1507.08311v1 |
2015-09-01 | Excitation of surface and volume plasmons in metal nanocluster by fast electrons | Surface and volume plasmons excited in a metal cluster by moving electron and
corresponding inelastic scattering spectra are studied based on the
hydrodynamic approach. Along with the bulk losses traditionally taken into
account, the surface and radiative ones are also considered as the physical
mechanisms responsible ... | 1509.00405v2 |
2017-11-19 | Role of Helium-Hydrogen ratio on energetic interchange mode behaviour and its effect on ion temperature and micro-turbulence in LHD | In the Large helical device, a change of energetic particle mode is observed
as He concentration is varied in ion-ITB type experiments, having constant
electron density and input heating power but with a clear increase of central
ion temperature in He rich discharges. This activity consists of bursty, but
damped energe... | 1711.07097v2 |
2018-09-02 | CEPC Conceptual Design Report: Volume 1 - Accelerator | The Circular Electron Positron Collider (CEPC) is a large international
scientific project initiated and hosted by China. It is located in a 100-km
circumference underground tunnel. The accelerator complex consists of a linear
accelerator (Linac), a damping ring (DR), the Booster, the Collider and several
transport lin... | 1809.00285v1 |
2018-10-10 | 3D Simulations and MLT: II. Onsager's Ideal Turbulence | We simulate stellar convection at high Reynolds number (Re$\lesssim$7000)
with causal time stepping but no explicit viscosity. We use the 3D Euler
equations with shock capturing (Colella & Woodward 1984). Anomalous dissipation
of turbulent kinetic energy occurs as an emergent feature of advection
("Onsager damping"), c... | 1810.04659v4 |
2018-12-10 | H$_2$/HD molecular data for analysis of quasar spectra in search of varying constants | Absorption lines of H$_2$ and HD molecules observed at high redshift in the
line of sight towards quasars are a test ground to search for variation of the
proton-to-electron mass ratio $\mu$. For this purpose, results from
astronomical observations are compared with a compilation of molecular data of
the highest accura... | 1812.03628v2 |
2019-04-26 | Thermal equilibration in a one-dimensional damped harmonic crystal | The features for the unsteady process of thermal equilibration ("the fast
motions") in a one-dimensional harmonic crystal lying in a viscous environment
(e.g., a gas) are under investigation. It is assumed that initially the
displacements of all the particles are zero and the particle velocities are
random quantities w... | 1904.11902v7 |
2019-11-04 | The shape of the cosmic ray proton spectrum | Recent observations of cosmic ray protons in the energy range
$10^2$--$10^5$~GeV have revealed that the spectrum cannot be described by a
simple power law. A hardening of the spectrum around an energy of order few
hundred~GeV, first observed by the magnetic spectrometers PAMELA and AMS02, has
now been confirmed by seve... | 1911.01311v1 |
2021-08-31 | Toward 100% Spin-Orbit Torque Efficiency with High Spin-Orbital Hall Conductivity Pt-Cr Alloys | 5d transition metal Pt is the canonical spin Hall material for efficient
generation of spin-orbit torques (SOTs) in Pt/ferromagnetic layer (FM)
heterostructures. However, for a long while with tremendous engineering
endeavors, the damping-like SOT efficiencies (${\xi}_{DL}$) of Pt and Pt alloys
have still been limited ... | 2108.13857v3 |
2022-04-06 | Universal Relations for Neutron Star F-Mode and G-Mode Oscillations | Among the various oscillation modes of neutron stars, f- and g- modes are the
most likely to be ultimately observed in binary neutron star mergers. The
f-mode is known to correlate in normal neutron stars with their tidal
deformability, moment of inertia and quadrupole moment. Using a piecewise
polytropic parameterizat... | 2204.03037v2 |
2022-09-26 | Partially dissipative systems in the critical regularity setting, and strong relaxation limit | Many physical phenomena may be modelled by first order hyperbolic equations
with degenerate dissipative or diffusive terms. This is the case for example in
gas dynamics, where the mass is conserved during the evolution, but the
momentum balance includes a diffusion (viscosity) or damping (relaxation) term,
or, in numer... | 2209.12734v1 |
2023-05-09 | Lower semicontinuity of pullback attractors for a non-autonomous coupled system of strongly damped wave equations | The aim of this paper is to study the robustness of the family of pullback
attractors associated to a non-autonomous coupled system of strongly damped
wave equations, given by the following evolution system $$\left\{
\begin{array}{lr} u_{tt} - \Delta u + u + \eta(-\Delta)^{1/2}u_t +
a_{\epsilon}(t)(-\Delta)^{1/2}v_t = ... | 2305.05724v3 |
2023-06-23 | Nonlinear asymptotic stability and transition threshold for 2D Taylor-Couette flows in Sobolev spaces | In this paper, we investigate the stability of the 2-dimensional (2D)
Taylor-Couette (TC) flow for the incompressible Navier-Stokes equations. The
explicit form of velocity for 2D TC flow is given by $u=(Ar+\frac{B}{r})(-\sin
\theta, \cos \theta)^T$ with $(r, \theta)\in [1, R]\times \mathbb{S}^1$ being
an annulus and $... | 2306.13562v1 |
2023-08-14 | Temperature Evolution of Magnon Propagation Length in Tm$_3$Fe$_5$O$_{12}$ Thin Films: Roles of Magnetic Anisotropy and Gilbert Damping | The magnon propagation length ($\langle\xi\rangle$) of a ferro/ferrimagnet
(FM) is one of the key factors that controls the generation and propagation of
thermally-driven spin current in FM/heavy metal (HM) bilayer based
spincaloritronic devices. Theory predicts that for the FM layer,
$\langle\xi\rangle$ is inversely p... | 2308.07236v3 |
2023-09-19 | Impact of strain on the SOT-driven dynamics of thin film Mn$_3$Sn | Mn$_3$Sn, a metallic antiferromagnet with an anti-chiral 120$^\circ$ spin
structure, generates intriguing magneto-transport signatures such as a large
anomalous Hall effect, spin-polarized current with novel symmetries, anomalous
Nernst effect, and magneto-optic Kerr effect. When grown epitaxially as
MgO(110)[001]$\par... | 2309.10246v2 |
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