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1997-08-11
A theoretical study on the damping of collective excitations in a Bose-Einstein condensate
We study the damping of low-lying collective excitations of condensates in a weakly interacting Bose gas model within the framework of imaginary time path integral. A general expression of the damping rate has been obtained in the low momentum limit for both the very low temperature regime and the higher temperature re...
9708080v3
1997-09-24
Damping in dilute Bose gases: a mean-field approach
Damping in a dilute Bose gas is investigated using a mean-field approximation which describes the coupled oscillations of condensate and non-condensate atoms in the collisionless regime. Explicit results for both Landau and Beliaev damping rates are given for non-uniform gases. In the case of uniform systems we obtain ...
9709259v1
2000-09-01
Damped Bogoliubov excitations of a condensate interacting with a static thermal cloud
We calculate the damping of condensate collective excitations at finite temperatures arising from the lack of equilibrium between the condensate and thermal atoms. We neglect the non-condensate dynamics by fixing the thermal cloud in static equilibrium. We derive a set of generalized Bogoliubov equations for finite tem...
0009021v2
2000-11-20
Cavity assisted quasiparticle damping in a Bose-Einstein condensate
We consider an atomic Bose-Einstein condensate held within an optical cavity and interacting with laser fields. We show how the interaction of the cavity mode with the condensate can cause energy due to excitations to be coupled to a lossy cavity mode, which then decays, thus damping the condensate, how to choose param...
0011341v2
2002-12-16
The nonlinear damping of Bose-Einstein condensate oscillations at ultra-low temperatures
We analyze the damping of the transverse breathing mode in an elongated trap at ultralow temperatures. The damping occurs due to the parametric resonance entailing the energy transfer to the longitudinal degrees of freedom. It is found that the nonlinear coupling between the transverse and discrete longitudinal modes c...
0212377v2
2004-08-27
Tunable magnetization damping in transition metal ternary alloys
We show that magnetization damping in Permalloy, Ni80Fe20 (``Py''), can be enhanced sufficiently to reduce post-switching magnetization precession to an acceptable level by alloying with the transition metal osmium (Os). The damping increases monotonically upon raising the Os-concentration in Py, at least up to 9% of O...
0408608v1
2005-03-06
Nonlinear damping in nanomechanical beam oscillator
We investigate the impact of nonlinear damping on the dynamics of a nanomechanical doubly clamped beam. The beam is driven into nonlinear regime and the response is measured by a displacement detector. For data analysis we introduce a nonlinear damping term to Duffing equation. The experiment shows conclusively that ac...
0503130v2
2006-05-23
The origin of increase of damping in transition metals with rare earth impurities
The damping due to rare earth impurities in transition metals is discussed in the low concentration limit. It is shown that the increase in damping is mainly due to the coupling of the orbital moments of the rare earth impurities and the conduction $p$-electrons. It is shown that an itinerant picture for the host trans...
0605583v1
2001-05-14
Simplified models of electromagnetic and gravitational radiation damping
In previous work the authors analysed the global properties of an approximate model of radiation damping for charged particles. This work is put into context and related to the original motivation of understanding approximations used in the study of gravitational radiation damping. It is examined to what extent the res...
0105045v1
1994-06-07
Damping Rate of a Yukawa Fermion at Finite Temperature
The damping of a massless fermion coupled to a massless scalar particle at finite temperature is considered using the Braaten-Pisarski resummation technique. First the hard thermal loop diagrams of this theory are extracted and effective Green's functions are constructed. Using these effective Green's functions the dam...
9406242v1
2006-05-02
Moduli decay in the hot early Universe
We consider moduli fields interacting with thermalized relativistic matter. We determine the temperature dependence of their damping rate and find it is dominated by thermal effects in the high temperature regime, i.e. for temperatures larger than their mass. For a simple scalar model the damping rate is expressed thro...
0605030v2
2006-11-27
Inviscid limit for damped and driven incompressible Navier-Stokes equations in ${{\mathbb R}^2}$
We consider the zero viscosity limit of long time averages of solutions of damped and driven Navier-Stokes equations in ${\mathbb R}^2$. We prove that the rate of dissipation of enstrophy vanishes. Stationary statistical solutions of the damped and driven Navier-Stokes equations converge to renormalized stationary stat...
0611782v1
2003-09-09
Traveling solitons in the damped driven nonlinear Schrödinger equation
The well known effect of the linear damping on the moving nonlinear Schr\"odinger soliton (even when there is a supply of energy via the spatially homogeneous driving) is to quench its momentum to zero. Surprisingly, the zero momentum does not necessarily mean zero velocity. We show that two or more parametrically driv...
0309031v1
2001-11-25
The Landau Damping Effect and Complex-valued Nature of Physical Quantities
Within the framework of the hypothesis offered by authors about complex-valued nature of physical quantities, the effect of the Landau damping has been explored with assumption that not only frequency can be a small imaginary component but also a wave vector. The numerical solution of the obtained dispersion equation t...
0111176v1
2005-10-14
Nontrapping arrest of Langmuir wave damping near the threshold amplitude
Evolution of a Langmuir wave is studied numerically for finite amplitudes slightly above the threshold which separates damping from nondamping cases. Arrest of linear damping is found to be a second-order effect due to ballistic evolution of perturbations, resonant power transfer between field and particles, and organi...
0510131v3
2000-06-22
Decoherence and Entanglement in Two-mode Squeezed Vacuum States
I investigate the decoherence of two-mode squeezed vacuum states by analyzing the relative entropy of entanglement. I consider two sources of decoherence: (i) the phase damping and (ii) the amplitude damping due to the coupling to the thermal environment. In particular, I give the exact value of the relative entropy of...
0006100v1
2006-08-02
Damped Population Oscillation in a Spontaneously Decaying Two-Level Atom Coupled to a Monochromatic Field
We investigate the time evolution of atomic population in a two-level atom driven by a monochromatic radiation field, taking spontaneous emission into account. The Rabi oscillation exhibits amplitude damping in time caused by spontaneous emission. We show that the semiclassical master equation leads in general to an ov...
0608020v1
2007-08-28
Linear frictional forces cause orbits to neither circularize nor precess
For the undamped Kepler potential the lack of precession has historically been understood in terms of the Runge-Lenz symmetry. For the damped Kepler problem this result may be understood in terms of the generalization of Poisson structure to damped systems suggested recently by Tarasov[1]. In this generalized algebraic...
0708.3827v3
2008-12-11
Frequency-dependent Drude damping in Casimir force calculations
The Casimir force is calculated between Au thin films that are described by a Drude model with a frequency dependent damping function. The model parameters are obtained from available experimental data for Au thin films. Two cases are considered; annealed and nonannealed films that have a different damping function. Co...
0812.2209v1
2008-12-18
Dipole Oscillations of a Fermi Gas in a Disordered Trap: Damping and Localization
We theoretically study the dipole oscillations of an ideal Fermi gas in a disordered trap. We show that even weak disorder induces strong damping of the oscillations and we identify a metal-insulator crossover. For very weak disorder, we show that damping results from a dephasing effect related to weak random perturbat...
0812.3501v2
2009-03-11
Confronting the damping of the baryon acoustic oscillations with observation
We investigate the damping of the baryon acoustic oscillations in the matter power spectrum due to the quasinonlinear clustering and redshift-space distortions by confronting the models with the observations of the Sloan Digital Sky Survey luminous red galaxy sample. The chi-squared test suggests that the observed powe...
0903.1883v1
2009-04-10
Spectral deviations for the damped wave equation
We prove a Weyl-type fractal upper bound for the spectrum of the damped wave equation, on a negatively curved compact manifold. It is known that most of the eigenvalues have an imaginary part close to the average of the damping function. We count the number of eigenvalues in a given horizontal strip deviating from this...
0904.1736v1
2009-10-26
Pressure Fronts in 1D Damped Nonlinear Lattices
The propagation of pressure fronts (impact solutions) in 1D chains of atoms coupled by anharmonic potentials between nearest neighbor and submitted to damping forces preserving uniform motion, is investigated. Travelling fronts between two regions at different uniform pressures are found numerically and well approximat...
0910.4890v1
2009-11-05
Bloch oscillations in lattice potentials with controlled aperiodicity
We numerically investigate the damping of Bloch oscillations in a one-dimensional lattice potential whose translational symmetry is broken in a systematic manner, either by making the potential bichromatic or by introducing scatterers at distinct lattice sites. We find that the damping strongly depends on the ratio of ...
0911.1108v3
2010-01-12
Decoherence and damping in ideal gases
The particle and current densities are shown to display damping and undergo decoherence in ideal quantum gases. The damping is read off from the equations of motion reminiscent of the Navier-Stokes equations and shows some formal similarity with Landau damping. The decoherence leads to consistent density and current hi...
1001.1803v2
2010-05-14
The effect of spin magnetization in the damping of electron plasma oscillations
The effect of spin of particles in the propagation of plasma waves is studied using a semi-classical kinetic theory for a magnetized plasma. We focus in the simple damping effects for the electrostatic wave modes besides Landau damping. Without taking into account more quantum effects than spin contribution to Vlasov's...
1005.2573v1
2010-06-01
Recent Progress on a Manifold Damped and Detuned Structure for CLIC
A damped detuned structure for the main X-band linacs of CLIC is being investigated as an alternative design to the present baseline heavily damped structure. In our earlier designs we studied detuned structures, operating at 11.994 GHz, with a range of dipole bandwidths in order to ensure the structure satisfies beam ...
1006.0087v1
2010-07-21
Finite temperature damping of collective modes of a BCS-BEC crossover superfluid
A new mechanism is proposed to explain the puzzling damping of collective excitations, which was recently observed in the experiments of strongly interacting Fermi gases below the superfluid critical temperature on the fermionic (BCS) side of Feshbach resonance. Sound velocity, superfluid density and damping rate are c...
1007.3694v2
2010-08-04
Confinement induced by fermion damping in three-dimensional QED
The three-dimensional non-compact QED is known to exhibit weak confinement when fermions acquire a finite mass via the mechanism of dynamical chiral symmetry breaking. In this paper, we study the effect of fermion damping caused by elastic scattering on the classical potential between fermions. By calculating the vacuu...
1008.0736v2
2011-06-22
Highly Damped Quasinormal Modes and the Small Scale Structure of Quantum Corrected Black Hole Exteriors
Quasinormal modes provide valuable information about the structure of spacetime outside a black hole. There is also a conjectured relationship between the highly damped quasinormal modes and the semi-classical spectrum of the horizon area/entropy. In this paper, we show that for spacetimes characterized by more than on...
1106.4357v1
2012-02-20
Simple Non-Markovian Microscopic Models for the Depolarizing Channel of a Single Qubit
The archetypal one-qubit noisy channels ---depolarizing, phase-damping and amplitude-damping channels--- describe both Markovian and non-Markovian evolution. Simple microscopic models for the depolarizing channel, both classical and quantum, are considered. Microscopic models which describe phase damping and amplitude ...
1202.4210v4
2012-05-11
On radiative damping in plasma-based accelerators
Radiative damping in plasma-based electron accelerators is analyzed. The electron dynamics under combined influence of the constant accelerating force and the classical radiation reaction force is studied. It is shown that electron acceleration cannot be limited by radiation reaction. If initially the accelerating forc...
1205.2436v1
2012-06-14
Damping of optomechanical disks resonators vibrating in air
We report on miniature GaAs disk optomechanical resonators vibrating in air in the radiofrequency range. The flexural modes of the disks are studied by scanning electron microscopy and optical interferometry, and correctly modeled with the elasticity theory for annular plates. The mechanical damping is systematically m...
1206.3032v1
2012-07-09
A Generalized Interpolation Inequality and its Application to the Stabilization of Damped Equations
In this paper, we establish a generalized H{\"o}lder's or interpolation inequality for weighted spaces in which the weights are non-necessarily homogeneous. We apply it to the stabilization of some damped wave-like evolution equations. This allows obtaining explicit decay rates for smooth solutions for more general cla...
1207.2030v2
2012-07-10
Conformation dependent damping and generalization of fluctuation-dissipation relation
Damping on an object generally depends on its conformation (shape size etc.). We consider the Langevin dynamics of a model system with a conformation dependent damping and generalize the fluctuation dissipation relation to fit in such a situation. We derive equilibrium distribution function for such a case which conver...
1207.2218v2
2012-10-30
On algebraic damping close to inhomogeneous Vlasov equilibria in multi-dimensional spaces
We investigate the asymptotic damping of a perturbation around inhomogeneous stable stationary states of the Vlasov equation in spatially multi-dimensional systems. We show that branch singularities of the Fourier-Laplace transform of the perturbation yield algebraic dampings. In two spatial dimensions, we classify the...
1210.8040v1
2013-04-07
Phenomenological model of anomalous magnon softening and damping in half-metallic manganites
To describe anomalous zone-boundary softening and damping of magnons in manganites we present a phenomenological two-fluid model containing ferromagnetic Fermi-liquid and non-Fermi-liquid components. The Fermi-liquid component accounts for softening of zone-boundary magnons and for the Landau damping of magnons in the ...
1304.1983v1
2013-04-25
Determination of Transverse Density Structuring from Propagating MHD Waves in the Solar Atmosphere
We present a Bayesian seismology inversion technique for propagating magnetohydrodynamic (MHD) transverse waves observed in coronal waveguides. The technique uses theoretical predictions for the spatial damping of propagating kink waves in transversely inhomogeneous coronal waveguides. It combines wave amplitude dampin...
1304.6869v1
2013-07-08
Optimal decay rate of the bipolar Euler-Poisson system with damping in $\mathbb{R}^3$
By rewriting a bipolar Euler-Poisson equations with damping into an Euler equation with damping coupled with an Euler-Poisson equation with damping, and using a new spectral analysis, we obtain the optimal decay results of the solutions in $L^2$-norm, which improve theose in \cite{Li3, Wu3}. More precisely, the velocit...
1307.2081v1
2013-07-27
Symmetry considerations on radiation damping
It is well known that a direct Lagrangian description of radiation damping is still missing. In this paper we will use a specific approach of this problem which is the standard way to treat the radiation damping problem. The objectives here are to construct: a N=2 supersymmetric extension for the model describing the r...
1307.7319v1
2014-02-10
Damping of a nanocantilever by paramagnetic spins
We compute damping of mechanical oscillations of a cantilever that contains flipping paramagnetic spins. This kind of damping is mandated by the dynamics of the total angular momentum, spin + mechanical. Rigorous expression for the damping rate is derived in terms of measurable parameters. The effect of spins on the qu...
1402.2326v1
2014-02-20
Long-time behavior of solutions of a BBM equation with generalized damping
We study the long-time behavior of the solution of a damped BBM equation $u_t + u_x - u_{xxt} + uu_x + \mathscr{L}_{\gamma}(u) = 0$. The proposed dampings $\mathscr{L}_{\gamma}$ generalize standards ones, as parabolic ($\mathscr{L}_{\gamma}(u)=-\Delta u$) or weak damping ($\mathscr{L}_{\gamma}(u)=\gamma u$) and allows ...
1402.5009v1
2014-02-24
N=2 supersymmetric radiation damping problem on a noncommutative plane
It is well known that a direct Lagrangian description of radiation damping is still missing. In this paper a specific approach of this problem was used, which is the standard way to treat the radiation damping problem. A $N=2$ supersymmetric extension for the model describing the radiation damping on the noncommutative...
1402.6996v1
2014-11-03
Renormalized solutions to the continuity equation with an integrable damping term
We consider the continuity equation with a nonsmooth vector field and a damping term. In their fundamental paper, DiPerna and Lions proved that, when the damping term is bounded in space and time, the equation is well posed in the class of distributional solutions and the solution is transported by suitable characteris...
1411.0451v1
2015-02-07
Landau Damping in a Mixture of Bose and Fermi Superfluids
We study the Landau damping in Bose-Fermi superfluid mixture at finite temperature. We find that at low temperature, the Landau damping rate will be exponentially suppressed at both the BCS side and the BEC side of Fermi superfluid. The momentum dependence of the damping rate is obtained, and it is quite different from...
1502.02116v1
2015-03-20
Applying a formula for generator redispatch to damp interarea oscillations using synchrophasors
If an interarea oscillatory mode has insufficient damping, generator redispatch can be used to improve its damping. We explain and apply a new analytic formula for the modal sensitivity to rank the best pairs of generators to redispatch. The formula requires some dynamic power system data and we show how to obtain that...
1503.06144v2
2016-01-21
Codeword Stabilized Quantum Codes for Asymmetric Channels
We discuss a method to adapt the codeword stabilized (CWS) quantum code framework to the problem of finding asymmetric quantum codes. We focus on the corresponding Pauli error models for amplitude damping noise and phase damping noise. In particular, we look at codes for Pauli error models that correct one or two ampli...
1601.05763v1
2016-02-08
On Boundary Damped Inhomogeneous Timoshenko Beams and Related Problems
We consider the model equations for the Timoshenko beam as a first order system in the framework of evolutionary equations. The focus is on boundary damping, which is implemented as a dynamic boundary condition. A change of material laws allows to include a large class of cases of boundary damping. By choosing a partic...
1602.02521v1
2016-02-13
Diffusion phenomena for the wave equation with space-dependent damping in an exterior domain
In this paper, we consider the asymptotic behavior of solutions to the wave equation with space-dependent damping in an exterior domain. We prove that when the damping is effective, the solution is approximated by that of the corresponding heat equation as time tends to infinity. Our proof is based on semigroup estimat...
1602.04318v1
2016-02-29
Robust quantum state recovery from amplitude damping within a mixed states framework
Due to the interaction with the environment, a quantum state is subjected to decoherence which becomes one of the biggest problems for practical quantum computation. Amplitude damping is one of the most important decoherence processes. Here, we show that general two-qubit mixed states undergoing an amplitude damping ca...
1602.08865v1
2016-05-23
Large time behaivor of global solutions to nonlinear wave equations with frictional and viscoelastic damping terms
In this paper, we study the Cauchy problem for a nonlinear wave equation with frictional and viscoelastic damping terms. As is pointed out by [8], in this combination, the frictional damping term is dominant for the viscoelastic one for the global dynamics of the linear equation. In this note we observe that if the ini...
1605.07232v1
2016-07-21
Protecting and enhancing spin squeezing under decoherence using weak measurement
We propose an efficient method to protect spin squeezing under the action of amplitude-damping, depolarizing and phase-damping channels based on measurement reversal from weak measurement, and consider an ensemble of N independent spin-1/2 particles with exchange symmetry. We find that spin squeezing can be enhanced gr...
1607.06530v2
2016-09-05
Remarks on an elliptic problem arising in weighted energy estimates for wave equations with space-dependent damping term in an exterior domain
This paper is concerned with weighted energy estimates and diffusion phenomena for the initial-boundary problem of the wave equation with space-dependent damping term in an exterior domain. In this analysis, an elliptic problem was introduced by Todorova and Yordanov. This attempt was quite useful when the coefficient ...
1609.01063v2
2016-11-16
Finite-orbit-width effects on the geodesic acoustic mode in the toroidally rotating tokamak plasma
The Landau damping of geodesic acoustic mode (GAM) in a torodial rotating tokamak plasma is analytically investigated by taking into account the finite-orbit-width (FOW) resonance effect to the 3rd order. The analytical result is shown to agree well with the numerical solution. The dependence of the damping rate on the...
1611.05168v1
2017-03-09
Long-time dynamics of the strongly damped semilinear plate equation in $\mathbb{R}^{n}$
We investigate the initial-value problem for the semilinear plate equation containing localized strong damping, localized weak damping and nonlocal nonlinearity. We prove that if nonnegative damping coefficients are strictly positive almost everywhere in the exterior of some ball and the sum of these coefficients is po...
1703.03485v2
2017-04-21
The Effects of Rolling Deformation and Annealing Treatment on Damping Capacity of 1200 Aluminium Alloy
Annealing treatment is an important step of rolling deformation that contributes to microstructural evolution and leads to the significant changes in damping capacity. Damping capacities were analyzed in the parallel to rolling direction at 1 and 10 Hz respectively. It was found that severe plastic deformation at 40 pe...
1704.07362v1
2017-07-12
Isolated resonances and nonlinear damping
We analyze isolated resonance curves (IRCs) in a single-degree-of-freedom system with nonlinear damping. The adopted procedure exploits singularity theory in conjunction with the harmonic balance method. The analysis unveils a geometrical connection between the topology of the damping force and IRCs. Specifically, we d...
1707.03561v2
2017-07-25
Best exponential decay rate of energy for the vectorial damped wave equation
The energy of solutions of the scalar damped wave equation decays uniformly exponentially fast when the geometric control condition is satisfied. A theorem of Lebeau [leb93] gives an expression of this exponential decay rate in terms of the average value of the damping terms along geodesics and of the spectrum of the i...
1707.07893v1
2017-08-20
Radiation Damping of a Polarizable Particle
A polarizable body moving in an external electromagnetic field will slow down. This effect is referred to as radiation damping and is analogous to Doppler cooling in atomic physics. Using the principles of special relativity we derive an expression for the radiation damping force and find that it solely depends on the ...
1708.06628v1
2017-09-13
Energy decay for the Klein-Gordon equation with highly oscillating damping
We consider the free Klein-Gordon equation with periodic damping. We show on this simple model that if the usual geometric condition holds then the decay of the energy is uniform with respect to the oscillations of the damping, and in particular the size of the derivatives do not play any role. We also show that withou...
1709.04197v1
2017-11-01
Analysis of A Splitting Scheme for Damped Stochastic Nonlinear Schrödinger Equation with Multiplicative Noise
In this paper, we investigate the damped stochastic nonlinear Schr\"odinger(NLS) equation with multiplicative noise and its splitting-based approximation. When the damped effect is large enough, we prove that the solutions of the damped stochastic NLS equation and the splitting scheme are exponential stable and possess...
1711.00516v2
2017-12-31
Stabilization of the weakly coupled wave-plate system with one internal damping
This paper is addressed to a stabilization problem of a system coupled by a wave and a Euler-Bernoulli plate equation. Only one equation is supposed to be damped. Under some assumption about the damping and the coupling terms, it is shown that sufficiently smooth solutions of the system decay logarithmically at infinit...
1801.00232v1
2018-05-10
Dynamics of coherence-induced state ordering under Markovian channels
We study the dynamics of coherence-induced state ordering under incoherent channels, particularly four specific Markovian channels: $-$ amplitude damping channel, phase damping channel, depolarizing channel and bit flit channel for single-qubit states. We show that the amplitude damping channel, phase damping channel, ...
1805.03898v1
2018-08-19
Sharp lifespan estimates of blowup solutions to semilinear wave equations with time-dependent effective damping
We consider the initial value problem for the semilinear wave equation with time-dependent effective damping. The interest is the behavior of lifespan of solutions in view of the asymptotic profile of the damping as $t\to \infty$. The result of this paper is the sharp lifespan estimates of blowup solutions for general ...
1808.06189v2
2018-09-05
Damping estimates for oscillatory integral operators with real-analytic phases and its applications
In this paper, we investigate sharp damping estimates for a class of one dimensional oscillatory integral operators with real-analytic phases. By establishing endpoint estimates for suitably damped oscillatory integral operators, we are able to give a new proof of the sharp $L^p$ estimates which have been proved by Xia...
1809.01298v2
2018-09-26
Global Attractor For Weakly Damped, Forced Mkdv Equation Below Energy Space
We prove the existence of the global attractor in $ \dot H^s$, $s > 11/12$ for the weakly damped and forced mKdV on the one dimensional torus. The existence of global attractor below the energy space has not been known, though the global well-posedness below the energy space is established. We directly apply the I-meth...
1809.09787v1
2018-10-03
Damped Oscillator with delta-kicked frequency in probability representation of quantum mechanic
We obtain the tomogram of squeezed correlated states of a quantum parametric damped oscillator in an explicit form. We study the damping within the framework of the Caldirola--Kanai model and chose the parametric excitation in the form of a very short pulse simulated by a delta-kick of frequency; the squeezing phenomen...
1810.01672v1
2018-10-26
Drastic Reduction of Plasmon Damping in Two-Dimensional Electron Disks
The plasmon damping has been investigated using resonant microwave absorption of two-dimensional electrons in disks with different diameters. We have found an unexpected drastic reduction of the plasmon damping in the regime of strong retardation. This finding implies large delocalization of retarded plasmon field outs...
1811.01040v1
2019-01-05
Cauchy problem for thermoelastic plate equations with different damping mechanisms
In this paper we study Cauchy problem for thermoelastic plate equations with friction or structural damping in $\mathbb{R}^n$, $n\geq1$, where the heat conduction is modeled by Fourier's law. We explain some qualitative properties of solutions influenced by different damping mechanisms. We show which damping in the mod...
1901.01423v2
2019-03-04
Damping of cosmological tensor modes in Horndeski theories after GW170817
This paper investigates the propagation of cosmological gravitational waves interacting with free-streaming neutrinos within the context of Horndeski theories of gravity constrained by the detection of GW170817. We apply the theory of cosmological perturbations to explicitly derive the Einstein-Boltzmann equation for t...
1903.01502v2
2019-04-24
On the Energy Decay Rate of the Fractional Wave Equation on $\mathbb{R}$ with Relatively Dense Damping
We establish upper bounds for the decay rate of the energy of the damped fractional wave equation when the averages of the damping coefficient on all intervals of a fixed length are bounded below. If the power of the fractional Laplacian, $s$, is between 0 and 2, the decay is polynomial. For $s \ge 2$, the decay is exp...
1904.10946v3
2019-08-22
Damping of the Anderson-Bogolyubov mode by spin and mass imbalance in Fermi mixtures
We study the temporally nonlocal contributions to the gradient expansion of the pair fluctuation propagator for spin- and mass-imbalanced Fermi mixtures. These terms are related to damping processes of sound-like (Anderson-Bogolyubov) collective modes and are relevant for the structure of the complex pole of the pair f...
1908.08559v2
2019-11-05
On the Smallness Condition in Linear Inviscid Damping: Monotonicity and Resonance Chains
We consider the linearized Euler equations around a smooth, bilipschitz shear profile $U(y)$ on $\mathbb{T}_L \times \mathbb{R}$. We construct an explicit flow which exhibits linear inviscid damping for $L$ sufficiently small, but for which damping fails if $L$ is large. In particular, similar to the instability result...
1911.02066v1
2020-01-02
On Echo Chains in Landau damping: Self-similar Solutions and Gevrey 3 as a Linear Stability Threshold
We show that the linearized Vlasov-Poisson equations around self-similar non-homogeneous states near zero contain the full plasma echo mechanism, yielding Gevrey 3 as a critical stability class. Moreover, here Landau damping may persist despite blow-up: We construct a critical Gevrey regularity class in which the force...
2001.00513v1
2020-01-21
Pseudospectra of the damped wave equation with unbounded damping
We analyze pseudospectra of the generator of the damped wave equation with unbounded damping. We show that the resolvent norm diverges as $\Re z \to - \infty$. The highly non-normal character of the operator is a robust effect preserved even when a strong potential is added. Consequently, spectral instabilities and oth...
2001.07767v1
2020-02-09
The damped wave equation with singular damping
We analyze the spectral properties and peculiar behavior of solutions of a damped wave equation on a finite interval with a singular damping of the form $\alpha/x$, $\alpha>0$. We establish the exponential stability of the semigroup for all positive $\alpha$, and determine conditions for the spectrum to consist of a fi...
2002.03440v1
2020-03-12
Optimal nonlinear damping control of second-order systems
Novel nonlinear damping control is proposed for the second-order systems. The proportional output feedback is combined with the damping term which is quadratic to the output derivative and inverse to the set-point distance. The global stability, passivity property, and convergence time and accuracy are demonstrated. Al...
2003.05670v3
2020-06-24
Stability of a star-shaped network with local Kelvin-Voigt damping and non-smooth coefficient at interface
In this paper, we study the stability problem of a star-shaped network of elastic strings with a local Kelvin-Voigt damping. Under the assumption that the damping coefficients have some singularities near the transmission point, we prove that the semigroup corresponding to the system is polynomially stable and the deca...
2006.14949v1
2020-11-06
A generalized finite element method for the strongly damped wave equation with rapidly varying data
We propose a generalized finite element method for the strongly damped wave equation with highly varying coefficients. The proposed method is based on the localized orthogonal decomposition introduced and is designed to handle independent variations in both the damping and the wave propagation speed respectively. The m...
2011.03311v1
2020-11-11
Reduction of back switching by large damping ferromagnetic material
Recent studies on magnetization dynamics induced by spin-orbit torque have revealed a weak dependence of the critical current for magnetization switching on the damping constant of a ferromagnetic free layer. This study, however, reveals that the damping constant nevertheless plays a key role in magnetization switching...
2011.05566v1
2020-12-28
Nonlinear modal analysis of nonconservative systems: Extension of the periodic motion concept
As the motions of nonconservative autonomous systems are typically not periodic, the definition of nonlinear modes as periodic motions cannot be applied in the classical sense. In this paper, it is proposed 'make the motions periodic' by introducing an additional damping term of appropriate sign and magnitude. It is sh...
2101.00949v1
2021-02-28
Stability for an inverse source problem of the damped biharmonic plate equation
This paper is concerned with the stability of the inverse source problem for the damped biharmonic plate equation in three dimensions. The stability estimate consists of the Lipschitz type data discrepancy and the high frequency tail of the source function, where the latter decreases as the upper bound of the frequency...
2103.00461v1
2021-04-12
Lp-asymptotic stability of 1D damped wave equations with localized and linear damping
In this paper, we study the $L^p$-asymptotic stability of the one-dimensional linear damped wave equation with Dirichlet boundary conditions in $[0,1]$, with $p\in (1,\infty)$. The damping term is assumed to be linear and localized to an arbitrary open sub-interval of $[0,1]$. We prove that the semi-group $(S_p(t))_{t\...
2104.05679v1
2021-05-13
Sharp Polynomial Decay for Waves Damped from the Boundary in Cylindrical Waveguides
We study the decay of global energy for the wave equation with H\"older continuous damping placed on the $C^{1,1}$-boundary of compact and non-compact waveguides with star-shaped cross-sections. We show there is sharp $t^{-1/2}$-decay when the damping is uniformly bounded from below on the cylindrical wall of product c...
2105.06566v1
2021-06-02
Stabilisation of the generalised Rao-Nakra beam by partial viscous damping
In this paper, we consider the stabilization of the generalized Rao-Nakra beam equation, which consists of four wave equations for the longitudinal displacements and the shear angle of the top and bottom layers and one Euler-Bernoulli beam equation for the transversal displacement. Dissipative mechanism are provided th...
2106.01189v1
2021-09-01
Vibration damping platform for cavity quantum-electrodynamics experiments
We present a mechanical platform with enhanced vibration damping properties for cavity quantum-electrodynamics experiments. It is based on a composite design that combines a soft, vibration-damping core with a rigid shell maintaining optical alignment. It passively damps the vibrations generated by piezoelectric actuat...
2109.00439v1
2021-09-05
Existence of a generalized polynomial attractor for the wave equation with nonlocal weak damping, anti-damping and critical nonlinearity
In this paper, we first establish a criterion based on contractive function for the existence of polynomial attractors. This criterion only involves some rather weak compactness associated with the repeated limit inferior and requires no compactness, which makes it suitable for critical cases. Then by this abstract the...
2109.01967v2
2021-11-29
Stabilization of coupled wave equations with viscous damping on cylindrical and non-regular domains: Cases without the geometric control condition
In this paper, we investigate the direct and indirect stability of locally coupled wave equations with local viscous damping on cylindrical and non-regular domains without any geometric control condition. If only one equation is damped, we prove that the energy of our system decays polynomially with the rate $t^{-\frac...
2111.14554v1
2022-01-25
Linear pair creation damping of high frequency plasma oscillation
We have studied the linear dispersion relation for Langmuir waves in plasmas of very high density, based on the Dirac-Heisenberg-Wigner formalism. The vacuum contribution to the physical observables leads to ultra-violet divergences, that are removed by a charge renormalization. The remaining vacuum contribution is sma...
2201.10370v1
2022-03-13
Continuum damping of topologically-protected edge modes at the boundary of a magnetized plasma
Recent extension of the topological ideas to continuous systems with broken time-reversal symmetry, such as magnetized plasmas, provides new insights into the nature of scattering-free topologically-protected surface plasma waves (TSPWs). We demonstrate a unique characteristic of TSPWs propagating above the electron cy...
2203.06693v2
2022-04-21
On scattering and damping of Toroidal Alfven eigenmode by drift wave turbulence
We demonstrate analytically that, in toroidal plasmas, scattering by drift wave turbulence could lead to appreciable damping of toroidal Alfven eigenmodes via generation of short-wavelength electron Landau damped kinetic Alfven waves. A corresponding analytic expression of the damping rate is derived, and found to be, ...
2204.09876v1
2022-10-30
Intrinsic polynomial squeezing for Balakrishnan-Taylor beam models
We explore the energy decay properties related to a model in extensible beams with the so-called energy damping. We investigate the influence of the nonloncal damping coefficient in the stability of the model. We prove, for the first time, that the corresponding energy functional is squeezed by polynomial-like function...
2210.16931v1
2023-02-13
Damping of gravitational waves in f(R) gravity
We study the damping of $f(R)$ gravitational waves by matter in flat spacetime and in expanding universe. In the former case, we find that the Landau damping of scalar mode in $f(R)$ theory exists, while that of the tensor mode in general relativity does not; we also present the viscosity coefficients and dispersion re...
2302.06402v2
2023-07-11
Global smooth solution for the 3D generalized tropical climate model with partial viscosity and damping
The three-dimensional generalized tropical climate model with partial viscosity and damping is considered in this paper. Global well-posedness of solutions of the three-dimensional generalized tropical climate model with partial viscosity and damping is proved for $\alpha\geq\frac{3}{2}$ and $\beta\geq4$. Global smooth...
2307.05145v3
2023-08-07
Reconstruction of the initial data from the solutions of damped wave equations
In this paper, we consider two types of damped wave equations: the weakly damped equation and the strongly damped equation and show that the initial velocity from the solution on the unit sphere. This inverse problem is related to Photoacoustic Tomography (PAT), a hybrid medical imaging technique. PAT is based on gener...
2308.03362v1
2023-09-26
Sharp conditions for exponential and non-exponential uniform stabilization of the time dependent damped wave equation
It is classical that uniform stabilization of solutions to the damped wave equation is equivalent to the geometric control condition The author previously showed that, when the damping depends on time, a generalization of the geometric control condition implies uniform stabilization at an exponential rate. In this pape...
2309.15005v1
2023-10-19
The damped focusing cubic wave equation on a bounded domain
For the focusing cubic wave equation on a compact Riemannian manifold of dimension $3$, the dichotomy between global existence and blow-up for solutions starting below the energy of the ground state is known since the work of Payne and Sattinger. In the case of a damped equation, we prove that the dichotomy between glo...
2310.12644v2
2024-04-03
Damping Reveals Hidden Dimensions in Elastic Metastructures Through Induced Transparency
Damping typically results in attenuation of vibrations and elastic wave propagation in mechanical systems. Contrary to this conventional understanding, we demonstrate experimentally and explain theoretically the revival of an elastic wave transmitted through a periodic metastructure when a weak non-Hermitian defect (da...
2404.02979v1
1997-06-30
Damped Lyman Alpha Systems at High Redshift and Models of Protogalactic Disks
We employ observationally determined intrinsic velocity widths and column densities of damped Lyman-alpha systems at high redshift to investigate the distribution of baryons in protogalaxies within the context of a standard cold dark matter model. We proceed under the assumption that damped Lyman alpha systems represen...
9706290v1
2000-03-16
Non-existence of radiation damping of gravitational motions
A rigorous, non-perturbative proof that there is no radiation damping of gravitational motions.
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