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2014-02-26
Comparison of methods for numerical calculation of continuum damping
Continuum resonance damping is an important factor in determining the stability of certain global modes in fusion plasmas. A number of analytic and numerical approaches have been developed to compute this damping, particularly in the case of the toroidicity-induced shear Alfv\'en eigenmode. This paper compares results ...
1402.6389v1
2014-05-16
Quantum corrections to nonlinear ion acoustic wave with Landau damping
Quantum corrections to nonlinear ion acoustic wave with Landau damping have been computed using Wigner equation approach. The dynamical equation governing the time development of nonlinear ion acoustic wave with semiclassical quantum corrections is shown to have the form of higher KdV equation which has higher order no...
1405.4107v1
2014-05-19
Mesh Size and Damped Edge Effects in Micromagnetic Spin Wave Simulation
We have studied the dependence of spin wave dispersion on the characteristics of the mesh used in a finite element micromagnetic simulation. It is shown that the dispersion curve has a cut off at a frequency which is analytically predictable. The frequency depends on the average mesh length used for the simulation. Bas...
1405.4615v2
2014-07-08
Fourier-Hermite spectral representation for the Vlasov-Poisson system in the weakly collisional limit
We study Landau damping in the 1+1D Vlasov-Poisson system using a Fourier-Hermite spectral representation. We describe the propagation of free energy in phase space using forwards and backwards propagating Hermite modes recently developed for gyrokinetics [Schekochihin et al. (2014)]. The change in the electric field c...
1407.1932v1
2014-08-15
Linear hyperbolic equations with time-dependent propagation speed and strong damping
We consider a second order linear equation with a time-dependent coefficient c(t) in front of the "elastic" operator. For these equations it is well-known that a higher space-regularity of initial data compensates a lower time-regularity of c(t). In this paper we investigate the influence of a strong dissipation, nam...
1408.3499v1
2014-08-14
Particle Dynamics in Damped Nonlinear Quadrupole Ion Traps
We examine the motions of particles in quadrupole ion traps as a function of damping and trapping forces, including cases where nonlinear damping or nonlinearities in the electric field geometry play significant roles. In the absence of nonlinearities, particles are either damped to the trap center or ejected, while th...
1409.6262v1
2015-01-03
Finite-Parameters Feedback Control for Stabilizing Damped Nonlinear Wave Equations
In this paper we introduce a finite-parameters feedback control algorithm for stabilizing solutions of various classes of damped nonlinear wave equations. Specifically, stabilization the zero steady state solution of initial boundary value problems for nonlinear weakly and strongly damped wave equations, nonlinear wave...
1501.00556v1
2015-06-26
A Universal Damping Mechanism of Quantum Vibrations in Deep Sub-Barrier Fusion Reactions
We demonstrate the damping of quantum octupole vibrations near the touching point when two colliding nuclei approach each other in the mass-asymmetric $^{208}$Pb + $^{16}$O system, for which the strong fusion hindrance was clearly observed. We, for the first time, apply the random-phase approximation method to the heav...
1506.07963v1
2015-07-28
Phenomenology of chiral damping in noncentrosymmetric magnets
A phenomenology of magnetic chiral damping is proposed in the context of magnetic materials lacking inversion symmetry breaking. We show that the magnetic damping tensor adopts a general form that accounts for a component linear in magnetization gradient in the form of Lifshitz invariants. We propose different microsco...
1507.07762v1
2015-08-06
Phenomenological description of the nonlocal magnetization relaxation in magnonics, spintronics, and domain-wall dynamics
A phenomenological equation called Landau-Lifshitz-Baryakhtar (LLBar) equation, which could be viewed as the combination of Landau-Lifshitz (LL) equation and an extra "exchange damping" term, was derived by Baryakhtar using Onsager's relations. We interpret the origin of this "exchange damping" as nonlocal damping by l...
1508.01478v1
2016-01-05
Vlasov Simulations of Electron-Ion Collision Effects on Damping of Electron Plasma Waves
Collisional effects can play an essential role in the dynamics of plasma waves by setting a minimum damping rate and by interfering with wave-particle resonances. Kinetic simulations of the effects of electron-ion pitch angle scattering on Electron Plasma Waves (EPWs) are presented here. In particular, the effects of s...
1601.01002v1
2016-02-13
The effect of orbital damping during planet migration on the Inclination and Eccentricity Distributions of Neptune Trojans
We explore planetary migration scenarios for formation of high inclination Neptune Trojans (NTs) and how they are affected by the planetary migration of Neptune and Uranus. If Neptune and Uranus's eccentricity and inclination were damped during planetary migration, then their eccentricities and inclinations were higher...
1602.04303v1
2016-03-08
Damping of the Higgs and Nambu-Goldstone modes of superfluid Bose gases at finite temperatures
We study collective modes of superfluid Bose gases in optical lattices at commensurate fillings. We focus on the vicinity of the quantum phase transition to the Mott insulator, where there exists the Higgs amplitude mode in addition to the Nambu-Goldstone phase mode associated with the spontaneous U(1) symmetry breakin...
1603.02395v1
2016-04-12
Offline software for the DAMPE experiment
A software system has been developed for the DArk Matter Particle Explorer (DAMPE) mission, a satellite-based experiment. The DAMPE software is mainly written in C++ and steered using Python script. This article presents an overview of the DAMPE offline software, including the major architecture design and specific imp...
1604.03219v6
2016-04-18
Stabilization of Damped Waves on Spheres and Zoll Surfaces of Revolution
We study the strong stabilization of wave equations on some sphere-like manifolds, with rough damping terms which do not satisfy the geometric control condition posed by Rauch-Taylor and Bardos-Lebeau-Rauch. We begin with an unpublished result of G. Lebeau, which states that on S^d , the indicator function of the upper...
1604.05218v2
2016-07-25
Damping of parametrically excited magnons in the presence of the longitudinal spin Seebeck effect
The impact of the longitudinal spin Seebeck effect (LSSE) on the magnon damping in magnetic-insulator/nonmagnetic-metal bilayers was recently discussed in several reports. However, results of those experiments can be blurred by multimode excitation within the measured linewidth. In order to avoid possible intermodal in...
1607.07274v1
2016-07-27
Frequency dispersion of small-amplitude capillary waves in viscous fluids
This work presents a detailed study of the dispersion of capillary waves with small amplitude in viscous fluids using an analytically derived solution to the initial value problem of a small-amplitude capillary wave as well as direct numerical simulation. A rational parametrization for the dispersion of capillary waves...
1607.08266v1
2016-10-18
On the stability of the Bresse system with frictional damping
In this paper, we consider the Bresse system with frictional damping terms and prove some optimal decay results for the $L^2$-norm of the solution and its higher order derivatives. In fact, if we consider just one damping term acting on the second equation of the solution, we show that the solution does not decay at al...
1610.05500v2
2017-01-12
Blow-up for semilinear wave equations with the scale invariant damping and super-Fujita exponent
The blow-up for semilinear wave equations with the scale invariant damping has been well-studied for sub-Fujita exponent. However, for super-Fujita exponent, there is only one blow-up result which is obtained in 2014 by Wakasugi in the case of non-effective damping. In this paper we extend his result in two aspects by ...
1701.03232v3
2017-02-17
Transition of multi-diffusive states in a biased periodic potential
We study a frequency-dependent damping model of hyper-diffusion within the generalized Langevin equation. The model allows for the colored noise defined by its spectral density, assumed to be proportional to $\omega^{\delta-1}$ at low frequencies with $0<\delta<1$ (sub-Ohmic damping) or $1<\delta<2$ (super-Ohmic dampin...
1702.05370v1
2017-09-27
Wave turbulence in vibrating plates : the effect of damping
The effect of damping in the wave turbulence regime for thin vibrating plates is studied. An experimental method, allowing measurements of dissipation in the system at all scales, is first introduced. Practical experimental devices for increasing the dissipation are used. The main observable consequence of increasing t...
1709.09438v1
2017-11-02
Vibration Damping of Carbon Nanotube Assembly Materials
Vibration reduction is of great importance in various engineering applications, and a material that exhibits good vibration damping along with high strength and modulus has become more and more vital. Owing to the superior mechanical property of carbon nanotube (CNT), new types of vibration damping material can be deve...
1711.00623v1
2017-12-05
Dark Matter Annihilation from Nearby Ultra-compact Micro Halos to Explain the Tentative Excess at ~1.4 TeV in DAMPE data
The tentative 1.4 TeV excess in the $e^+e^-$ spectrum measured by The DArk Matter Particle Explorer (DAMPE) motivates the possible existence of one or more local dark matter concentrated regions. In particular, Ultra-compact Micro Halos (UCMHs) seeded by large density perturbations in the early universe, allocated with...
1712.01724v2
2017-12-21
A new charge reconstruction algorithm for the DAMPE silicon microstrip detector
The DArk Matter Particle Explorer (DAMPE) is one of the four satellites within the Strategic Pioneer Research Program in Space Science of the Chinese Academy of Science (CAS). The Silicon-Tungsten Tracker (STK), which is composed of 768 singled-sided silicon microstrip detectors, is one of the four subdetectors in DAMP...
1712.08011v1
2018-01-23
The dominancy of damping like torque for the current induced magnetization switching in Pt/Co/W multilayers
Two classes of spin-orbit coupling (SOC) mechanisms have been considered as candidate sources for the spin orbit torque (SOT): the spin Hall Effect (SHE) in heavy metals with strong SOC and the Rashba effect arising from broken inversion symmetry at material surfaces and interfaces. In this work, we have investigated t...
1801.07408v1
2018-02-20
The damped wave equation with unbounded damping
We analyze new phenomena arising in linear damped wave equations on unbounded domains when the damping is allowed to become unbounded at infinity. We prove the generation of a contraction semigroup, study the relation between the spectra of the semigroup generator and the associated quadratic operator function, the con...
1802.07026v1
2018-04-06
Exponential Integrators Preserving Local Conservation Laws of PDEs with Time-Dependent Damping/Driving Forces
Structure-preserving algorithms for solving conservative PDEs with added linear dissipation are generalized to systems with time-dependent damping/driving terms. This study is motivated by several PDE models of physical phenomena, such as Korteweg-de Vries, Klein-Gordon, Schr\"{o}dinger, and Camassa-Holm equations, all...
1804.02266v1
2018-05-29
Enhancing precision of damping rate by PT symmetric Hamiltonian
We utilize quantum Fisher information to investigate the damping parameter precision of a dissipative qubit. PT symmetric non-Hermitian Hamiltonian is used to enhance the parameter precision in two models: one is direct PT symmetric quantum feedback; the other is that the damping rate is encoded into a effective PT sym...
1805.11216v1
2018-05-31
Damping Effect on PageRank Distribution
This work extends the personalized PageRank model invented by Brin and Page to a family of PageRank models with various damping schemes. The goal with increased model variety is to capture or recognize a larger number of types of network activities, phenomena and propagation patterns. The response in PageRank distribut...
1806.00127v1
2018-08-10
Relativistic charge solitons created due to nonlinear Landau damping: A candidate for explaining coherent radio emission in pulsars
A potential resolution for the generation of coherent radio emission in pulsar plasma is the existence of relativistic charge solitons, which are solutions of nonlinear Schr\"{o}dinger equation (NLSE). In an earlier study, Melikidze et al. (2000) investigated the nature of these charge solitons; however, their analysis...
1808.03657v1
2018-11-21
Super Damping of Mechanical Vibrations
We report the phenomenon of coherent super decay, where a linear sum of several damped oscillators can collectively decay much faster than the individual ones in the first stage, followed by stagnating ones after more than 90 percent of the energy has already been dissipated. The parameters of the damped oscillators fo...
1811.08621v2
2018-11-29
Flowing fibers as a proxy of turbulence statistics
The flapping states of a flexible fiber fully coupled to a three-dimensional turbulent flow are investigated via state-of-the-art numerical methods. Two distinct flapping regimes are predicted by the phenomenological theory recently proposed by Rosti et al. [Phys. Rev. Lett. 121, 044501, 2018]: the under-damped regime,...
1811.12023v2
2018-11-29
The Lugiato-Lefever equation with nonlinear damping caused by two photon absorption
In this paper we investigate the effect of nonlinear damping on the Lugiato-Lefever equation $$ \i \partial_t a = -(\i-\zeta) a - da_{xx} -(1+\i\kappa)|a|^2a +\i f $$ on the torus or the real line. For the case of the torus it is shown that for small nonlinear damping $\kappa>0$ stationary spatially periodic solutions ...
1811.12200v3
2018-11-26
Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality
The dynamics of electron-plasma waves are described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite-Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency, and eigenmode spectrum of electr...
1811.12855v2
2019-01-17
Influences of interfacial oxidization on surface magnetic energy, magnetic damping and spin-orbit-torques in Pt / ferromagnet / capping structures
We investigate the effect of capping layer (CAP) on the interfacial magnetic anisotropy energy density (K_S), magnetic damping ({\alpha}), and spin-orbit torques (SOTs) in heavy-metal (Pt) / ferromagnet (Co or Py) / CAP (MgO/Ta, HfOx, or TaN). At room temperature (RT) the CAP materials influence the effective magnitude...
1901.05777v1
2019-05-31
The amplitude of solar p-mode oscillations from three-dimensional convection simulations
The amplitude of solar p-mode oscillations is governed by stochastic excitation and mode damping, both of which take place in the surface convection zone. However, the time-dependent, turbulent nature of convection makes it difficult to self-consistently study excitation and damping processes through the use of traditi...
1905.13397v2
2019-10-03
Many-body collision contributions to electron momentum damping rates in a plasma influenced by electron strong coupling
Experimental studies of electron-ion collision rates in an ultracold neutral plasma (UNP) can be conducted through measuring the rate of electron plasma oscillation damping. For sufficiently cold and dense conditions where strong coupling influences are important, the measured damping rate was faster by 37\% than theor...
1910.01707v1
2019-10-18
Escape of a forced-damped particle from weakly nonlinear truncated potential well
Escape from a potential well is an extreme example of transient behavior. We consider the escape of the harmonically forced particle under viscous damping from the benchmark truncated weakly nonlinear potential well. Main attention is paid to most interesting case of primary 1:1 resonance. The treatment is based on mul...
1910.08545v1
2019-10-24
Topological damping Rashba spin orbit torque in ballistic magnetic domain walls
Rashba spin orbit torque derived from the broken inversion symmetry at ferromagnet/heavy metal interfaces has potential application in spintronic devices. In conventional description of the precessional and damping components of the Rashba spin orbit torque in magnetization textures, the decomposition coefficients are ...
1910.10977v2
2019-11-13
Dipole oscillations of fermionic superfluids along the BEC-BCS crossover in disordered potentials
We investigate dipole oscillations of ultracold Fermi gases along the BEC-BCS crossover through disordered potentials. We observe a disorder-induced damping of oscillations as well as a change of the fundamental Kohn-mode frequency. The measurement results are compared to numerical density matrix renormalization group ...
1911.05638v1
2020-02-07
Model of damping and anisotropy at elevated temperatures: application to granular FePt films
Understanding the damping mechanism in finite size systems and its dependence on temperature is a critical step in the development of magnetic nanotechnologies. In this work, nano-sized materials are modeled via atomistic spin dynamics, the damping parameter being extracted from Ferromagnetic Resonance (FMR) simulation...
2002.02865v1
2020-04-06
Damping-like Torque in Monolayer 1T-TaS$_2$
A damping-like spin orbit torque (SOT) is a prerequisite for ultralow power spin logic devices. Here, we report on the damping-like SOT in just one monolayer of the conducting transition metal dichalcogenide (TMD) TaS$_2$ interfaced with a NiFe (Py) ferromagnetic layer. The charge-spin conversion efficiency is found to...
2004.02649v1
2020-05-15
Calibration and performance of the neutron detector onboard of the DAMPE mission
The DArk Matter Particle Explorer (DAMPE), one of the four space-based scientific missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, has been successfully launched on Dec. 17th 2015 from Jiuquan launch center. One of the most important scientific goals of...
2005.07828v1
2020-05-16
Simultaneous observation of anti-damping and inverse spin Hall effect in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$/Pt bilayer system
Manganites have shown potential in spintronics because they exhibit high spin polarization. Here, by ferromagnetic resonance we have studied the damping properties of La$_{0.67}$Sr$_{0.33}$MnO$_{3}$/Pt bilayers which are prepared by oxide molecular beam epitaxy. The damping coefficient ($\alpha$) of La$_{0.67}$Sr$_{0.3...
2005.07848v3
2020-07-16
Linearized wave-damping structure of Vlasov-Poisson in $\mathbb R^3$
In this paper we study the linearized Vlasov-Poisson equation for localized disturbances of an infinite, homogeneous Maxwellian background distribution in $\mathbb R^3_x \times \mathbb R^3_v$. In contrast with the confined case $\mathbb T^d _x \times \mathbb R_v ^d$, or the unconfined case $\mathbb R^d_x \times \mathbb...
2007.08580v1
2020-07-25
Using a Lindbladian approach to model decoherence in two coupled nuclear spins via correlated phase-damping and amplitude damping noise channels
In this work, we studied the relaxation dynamics of coherences of different order present in a system of two coupled nuclear spins. We used a previously designed model for intrinsic noise present in such systems which considers the Lindblad master equation for Markovian relaxation. We experimentally created zero-, sing...
2007.12972v1
2020-09-29
The effects of nonlinear damping on degenerate parametric amplification
This paper considers the dynamic response of a single degree of freedom system with nonlinear stiffness and nonlinear damping that is subjected to both resonant direct excitation and resonant parametric excitation, with a general phase between the two. This generalizes and expands on previous studies of nonlinear effec...
2009.14284v2
2020-11-10
Damped oscillators within the general theory of Casimir and van der Waals forces
It is demonstrated that the general theory of Casimir and van der Waals forces describes the interaction-induced equilibrium thermodynamic potentials of the damped harmonic oscillator bilinearly coupled to the environment. An extended model for a damped oscillator is suggested along the lines of the general theory of C...
2011.04960v2
2020-11-16
Technology to Counter Online Flaming Based on the Frequency-Dependent Damping Coefficient in the Oscillation Model
Online social networks, which are remarkably active, often experience explosive user dynamics such as online flaming, which can significantly impact the real world. However, countermeasures based on social analyses of the individuals causing flaming are too slow to be effective because of the rapidity with which the in...
2011.08117v1
2021-01-03
The effect of flow on resonant absorption of slow MHD waves in magnetic flux tubes
In this paper, we study kink and sausage oscillations in the presence of longitudinal background flow. We study resonant absorption of the kink and sausage modes in the slow continuum under magnetic pore conditions in the presence of flow. we determine the dispersion relation then solve it numerically, and find the fre...
2101.02064v1
2021-02-01
Blow-up and lifespan estimates for a damped wave equation in the Einstein-de Sitter spacetime with nonlinearity of derivative type
In this article, we investigate the blow-up for local solutions to a semilinear wave equation in the generalized Einstein - de Sitter spacetime with nonlinearity of derivative type. More precisely, we consider a semilinear damped wave equation with a time-dependent and not summable speed of propagation and with a time-...
2102.01137v2
2021-02-02
Analysis of Lower Hybrid Drift Waves in Kappa Distributions over Solar Atmosphere
Kappa distributions and with loss cone features have been frequently observed with flares emissions with the signatures of Lower hybrid waves. We have analysed the plasma with Kappa distributions and with loss cone features for the drift wave instabilities in perpendicular propagation for Large flare and Normal flare a...
2102.01323v1
2021-02-25
Regularity and stability of the semigroup associated with some interacting elastic systems I: A degenerate damping case
In this paper, we examine regularity and stability issues for two damped abstract elastic systems. The damping involves the average velocity and a fractional power $\theta$, with $\theta$ in $[-1,1]$, of the principal operator. The matrix operator defining the damping mechanism for the coupled system is degenerate. Fir...
2102.13217v4
2021-03-05
Existence and congruence of global attractors for damped and forced integrable and nonintegrable discrete nonlinear Schrödinger equations
We study two damped and forced discrete nonlinear Schr\"odinger equations on the one-dimensional infinite lattice. Without damping and forcing they are represented by the integrable Ablowitz-Ladik equation (AL) featuring non-local cubic nonlinear terms, and its standard (nonintegrable) counterpart with local cubic nonl...
2103.03533v1
2021-05-17
Dissipation of Oscillation Energy and Distribution of Damping Power in a Multimachine Power System: A Small-signal Analysis
This paper revisits the concept of damping torque in a multimachine power system and its relation to the dissipation of oscillation energy in synchronous machine windings. As a multimachine extension of an existing result on a single-machine-infinite-bus (SMIB) system, we show that the total damping power for a mode st...
2105.07618v2
2021-06-04
Imaging spin-wave damping underneath metals using electron spins in diamond
Spin waves in magnetic insulators are low-damping signal carriers that could enable a new generation of spintronic devices. The excitation, control, and detection of spin waves by metal electrodes is crucial for interfacing these devices to electrical circuits. It is therefore important to understand metal-induced damp...
2106.02508v2
2021-06-04
Inherent Non-Linear Damping in Resonators with Inertia Amplification
Inertia amplification is a mechanism coupling degrees of freedom within a vibrating structure. Its goal is to achieve an apparent high dynamic mass and, accordingly, a low resonance frequency. Such structures have been described for use in locally resonant metamaterials and phononic crystals to lower the starting frequ...
2106.02576v2
2021-06-30
On the effect of perturbations in first-order optimization methods with inertia and Hessian driven damping
Second-order continuous-time dissipative dynamical systems with viscous and Hessian driven damping have inspired effective first-order algorithms for solving convex optimization problems. While preserving the fast convergence properties of the Nesterov-type acceleration, the Hessian driven damping makes it possible to ...
2106.16159v2
2021-07-13
A new approach to the quantization of the damped harmonic oscillator
In this paper, a new approach for constructing Lagrangians for driven and undriven linearly damped systems is proposed, by introducing a redefined time coordinate and an associated coordinate transformation to ensure that the resulting Lagrangian satisfies the Helmholtz conditions. The approach is applied to canonicall...
2107.05827v3
2021-10-26
Theory of sound attenuation in amorphous solids from nonaffine motions
We present a theoretical derivation of acoustic phonon damping in amorphous solids based on the nonaffine response formalism for the viscoelasticity of amorphous solids. The analytical theory takes into account the nonaffine displacements in transverse waves and is able to predict both the ubiquitous low-energy diffusi...
2110.13446v2
2021-11-21
Energy Transport in 1-Dimensional Oscillator Arrays With Hysteretic Damping
Energy transport in 1-dimensional oscillator arrays has been extensively studied to date in the conservative case, as well as under weak viscous damping. When driven at one end by a sinusoidal force, such arrays are known to exhibit the phenomenon of supratransmission, i.e. a sudden energy surge above a critical drivin...
2111.10816v3
2021-12-15
An Innovative Transverse Emittance Cooling Technique using a Laser-Plasma Wiggler
We propose an innovative beam cooling scheme based on laser driven plasma wakefields to address the challenge of high luminosity generation for a future linear collider. For linear colliders, beam cooling is realised by means of damping rings equipped with wiggler magnets and accelerating cavities. This scheme ensures ...
2112.08163v1
2021-12-21
ISS-Based Robustness to Various Neglected Damping Mechanisms for the 1-D Wave PDE
This paper is devoted to the study of the robustness properties of the 1-D wave equation for an elastic vibrating string under four different damping mechanisms that are usually neglected in the study of the wave equation: (i) friction with the surrounding medium of the string (or viscous damping), (ii) thermoelastic p...
2112.11287v1
2022-01-20
Derivation of the linear Boltzmann equation from the damped quantum Lorentz gas with a general scatterer configuration
It is a fundamental problem in mathematical physics to derive macroscopic transport equations from microscopic models. In this paper we derive the linear Boltzmann equation in the low-density limit of a damped quantum Lorentz gas for a large class of deterministic and random scatterer configurations. Previously this re...
2201.08229v2
2022-01-22
Effect of MagneticField on the Damping Behavior of a Ferrofluid based Damper
This paper is an extension of our earlier work where we had reported a proof of concept for a ferrofluid based damper. The damper used ferrofluid as damping medium and it was seen that damping efficiency of the damper changes on application of magnetic field. The present paper deals with a systematic study of the effec...
2201.09027v1
2022-01-28
Machine learning-based method of calorimeter saturation correction for helium flux analysis with DAMPE experiment
DAMPE is a space-borne experiment for the measurement of the cosmic-ray fluxes at energies up to around 100 TeV per nucleon. At energies above several tens of TeV, the electronics of DAMPE calorimeter would saturate, leaving certain bars with no energy recorded. In the present work we discuss the application of machine...
2201.12185v3
2022-03-10
Accelerated gradient methods combining Tikhonov regularization with geometric damping driven by the Hessian
In a Hilbert setting, for convex differentiable optimization, we consider accelerated gradient dynamics combining Tikhonov regularization with Hessian-driven damping. The Tikhonov regularization parameter is assumed to tend to zero as time tends to infinity, which preserves equilibria. The presence of the Tikhonov regu...
2203.05457v2
2022-04-01
On the Importance of High-Frequency Damping in High-Order Conservative Finite-Difference Schemes for Viscous Fluxes
This paper discusses the importance of high-frequency damping in high-order conservative finite-difference schemes for viscous terms in the Navier-Stokes equations. Investigating nonlinear instability encountered in a high-resolution viscous shock-tube simulation, we have discovered that a modification to the viscous s...
2204.00393v1
2022-06-20
Stability and Damping in the Disks of Massive Galaxies
After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation. However, it is also known that despite this damping, there must be a degree of random l...
2206.09671v2
2022-08-25
The Effect of Frequency Droop Damping on System Parameters and Battery Sizing During Load Change Condition
Inverter-based resources (IBR) have been widely studied for their advantages on the current power systems. This increase in the penetration of renewable energy has raised some concerns about the stability of the existing grid. Historically, power systems are dominated by synchronous generators that can easily react to ...
2208.12291v1
2022-09-15
Superfluid $^4$He as a rigorous test bench for different damping models in nanoelectromechanical resonators
We have used nanoelectromechanical resonators to probe superfluid $^4$He at different temperature regimes, spanning over four orders of magnitude in damping. These regimes are characterized by the mechanisms which provide the dominant contributions to damping and the shift of the resonance frequency: tunneling two leve...
2209.07229v2
2022-11-08
On the injection scale of the turbulence in the partially ionized very local interstellar medium
The cascade of magnetohydrodynamic (MHD) turbulence is subject to ion-neutral collisional damping and neutral viscous damping in the partially ionized interstellar medium. By examining the damping effects in the warm and partially ionized local interstellar medium, we find that the interstellar turbulence is damped by ...
2211.04496v1
2022-12-11
The overtone level spacing of a black hole quasinormal frequencies: a fingerprint of a local $SL(2,\mathbb{R})$ symmetry
The imaginary part of the quasinormal frequencies spectrum for a static and spherically symmetric black hole is analytically known to be equally spaced, both for the highly damped and the weakly damped families of quasinormal modes. Some interesting attempts have been made in the last twenty years to understand in simp...
2212.05538v1
2022-12-15
Formation of shifted shock for the 3D compressible Euler equations with time-dependent damping
In this paper, we show the shock formation to the compressible Euler equations with time-dependent damping $\frac{a\p u}{(1+t)^{\lam}}$ in three spatial dimensions without any symmetry conditions. It's well-known that for $\lam>1$, the damping is too weak to prevent the shock formation for suitably large data. However,...
2212.07828v1
2023-01-15
Damped-driven system of bouncing droplets leading to deterministic diffusive behavior
Damped-driven systems are ubiquitous in science, however the damping and driving mechanisms are often quite convoluted. This manuscript presents an experimental and theoretical investigation of a fluidic droplet on a vertically vibrating fluid bath as a damped-driven system. We study a fluidic droplet in an annular cav...
2301.06041v2
2023-03-01
Generation of intraparticle quantum correlations in amplitude damping channel and its robustness
Quantum correlations between two or more different degrees of freedom of the same particle is sometimes referred to as intraparticle entanglement. In this work, we study these intra-particle correlations between two different degrees of freedom under various decoherence channels viz. amplitude damping, depolarising and...
2303.01238v1
2023-03-16
Quantum Brownian Motion in the Caldeira-Leggett Model with a Damped Environment
We model a quantum system coupled to an environment of damped harmonic oscillators by following the approach of Caldeira-Leggett and adopting the Caldirola-Kanai Lagrangian for the bath oscillators. In deriving the master equation of the quantum system of interest (a particle in a general potential), we show that the p...
2303.09516v1
2023-03-22
A Numerical Study of Landau Damping with PETSc-PIC
We present a study of the standard plasma physics test, Landau damping, using the Particle-In-Cell (PIC) algorithm. The Landau damping phenomenon consists of the damping of small oscillations in plasmas without collisions. In the PIC method, a hybrid discretization is constructed with a grid of finitely supported basis...
2303.12620v1
2023-04-07
Shifted shock formation for the 3D compressible Euler equations with damping and variation of the vorticity
In this paper, we consider the shock formation problem for the 3-dimensional(3D) compressible Euler equations with damping inspired by the work \cite{BSV3Dfulleuler}. It will be shown that for a class of large data, the damping can not prevent the formation of point shock, and the damping effect shifts the shock time a...
2304.03506v2
2023-07-05
Bayesian evidence for two slow-wave damping models in hot coronal loops
We compute the evidence in favour of two models, one based on field-aligned thermal conduction alone and another that includes thermal misbalance as well, in explaining the damping of slow magneto-acoustic waves in hot coronal loops. Our analysis is based on the computation of the marginal likelihood and the Bayes fact...
2307.02439v1
2023-07-24
From characteristic functions to multivariate distribution functions and European option prices by the damped COS method
We provide a unified framework for the computation of the distribution function and the computation of prices of financial options from the characteristic function of some density by the COS method. The classical COS method is numerically very efficient in one-dimension but cannot deal very well with certain financial ...
2307.12843v6
2023-07-26
A Nonlinear Damped Metamaterial: Wideband Attenuation with Nonlinear Bandgap and Modal Dissipation
In this paper, we incorporate the effect of nonlinear damping with the concept of locally resonant metamaterials to enable vibration attenuation beyond the conventional bandgap range. The proposed design combines a linear host cantilever beam and periodically distributed inertia amplifiers as nonlinear local resonators...
2307.14165v2
2023-07-28
Premature jump-down mimicks nonlinear damping in nanoresonators
Recent experiments on nano-resonators in a bistable regime use the `jump-down' point between states to infer mechanical properties of the membrane or a load, but often suggest the presence of some nonlinear damping. Motivated by such experiments, we develop a mechanical model of a membrane subject to a uniform, oscilla...
2307.15656v1
2023-09-22
Long time energy averages and a lower resolvent estimate for damped waves
We consider the damped wave equation on a compact manifold. We propose different ways of measuring decay of the energy (time averages of lower energy levels, decay for frequency localized data...) and exhibit links with resolvent estimates on the imaginary axis. As an application we prove a universal logarithmic lower ...
2309.12709v1
2023-10-11
Damping Density of an Absorptive Shoebox Room Derived from the Image-Source Method
The image-source method is widely applied to compute room impulse responses (RIRs) of shoebox rooms with arbitrary absorption. However, with increasing RIR lengths, the number of image sources grows rapidly, leading to slow computation. In this paper, we derive a closed-form expression for the damping density, which ch...
2310.07363v1
2023-10-14
Exploring Damping Effect of Inner Control Loops for Grid-Forming VSCs
This paper presents an analytical approach to explore the damping effect of inner loops on grid-forming converters. First, an impedance model is proposed to characterize the behaviors of inner loops, thereby illustrating their influence on output impedance shaping. Then, based on the impedance representation, the compl...
2310.09660v1
2023-10-24
Frictional weakening of a granular sheared layer due to viscous rolling revealed by Discrete Element Modeling
Considering a 3D sheared granular layer modeled with discrete elements, it is well known the rolling resistance significantly influences the mechanical behavior. Even if the rolling resistance role has been deeply investigated as it is commonly used to represent the the roughness of the grains and the interparticle loc...
2310.15945v1
2023-12-12
Coordination of Damping Controllers: A Data-Informed Approach for Adaptability
This work proposes a data-informed approach for an adaptable coordination of damping controllers. The novel concept of coordination is based on minimizing the Total Action, a single metric that measures the system's dynamic response post-disturbance. This is a performance measure based on the physics of the power syste...
2312.07739v1
2024-01-26
Efficient Control of Magnetization Dynamics Via W/CuO$_\text{x}$ Interface
Magnetization dynamics, which determine the speed of magnetization switching and spin information propagation, play a central role in modern spintronics. Gaining its control will satisfy the different needs of various spintronic devices. In this work, we demonstrate that the surface oxidized Cu (CuO$_\text{x}$) can be ...
2401.14708v1
2024-02-08
The stability analysis based on viscous theory of Faraday waves in Hele-Shaw cells
The linear instability of Faraday waves in Hele-Shaw cells is investigated with consideration of the viscosity of fluids after gap-averaging the governing equations due to the damping from two lateral walls and the dynamic behavior of contact angle. A new hydrodynamic model is thus derived and solved semi-analytically....
2402.05505v2
2024-02-09
Damping of density oscillations from bulk viscosity in quark matter
We study the damping of density oscillations in the quark matter phase that might occur in compact stars. To this end we compute the bulk viscosity and the associated damping time in three-flavor quark matter, considering both nonleptonic and semileptonic electroweak processes. We use two different equations of state o...
2402.06595v1
2003-08-05
Reliability of Calderbank-Shor-Steane Codes and Security of Quantum Key Distribution
After Mayers (1996, 2001) gave a proof of the security of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol, Shor and Preskill (2000) made a remarkable observation that a Calderbank-Shor-Steane (CSS) code had been implicitly used in the BB84 protocol, and suggested its security could be proven by bound...
0308029v6
2011-07-13
(In-)Stability of Singular Equivariant Solutions to the Landau-Lifshitz-Gilbert Equation
In this paper we use formal asymptotic arguments to understand the stability proper- ties of equivariant solutions to the Landau-Lifshitz-Gilbert model for ferromagnets. We also analyze both the harmonic map heatflow and Schrodinger map flow limit cases. All asymptotic results are verified by detailed numerical experim...
1107.2620v1
1996-09-10
The Damping Tail of CMB Anisotropies
By decomposing the damping tail of CMB anisotropies into a series of transfer functions representing individual physical effects, we provide ingredients that will aid in the reconstruction of the cosmological model from small-scale CMB anisotropy data. We accurately calibrate the model-independent effects of diffusion ...
9609079v1
1997-09-16
Lyman-alpha emission as a tool to study high redshift damped systems
We report a quantitative study of the escape of Lyman-alpha photons from an inhomogeneous optically thick medium that mimics the structure of damped Lyman-alpha absorbers. Modeling the optically thick disk with 3 components (massive stars and HII regions, dust, and neutral hydrogen), we study the resulting emission lin...
9709150v1
1997-10-17
The chemical evolution of galaxies causing damped Ly$α$ absorption
We have compiled all available data on chemical abundances in damped Lyman alpha absorption systems for comparison with results from our combined chemical and spectrophotometric galaxy evolution models. Preliminary results from chemically consistent calculations are in agreement with observations of damped Ly$\alpha$ s...
9710193v1
1998-01-26
Are Damped Lyman alpha Systems Rotating Disks ?
We report on high spectral resolution observations of five damped Lyman alpha systems whose line velocity profiles and abundances are analyzed. By combining these data with information from the literature, we study the kinematics of the low and high ionization phases of damped systems and discuss the possibility that p...
9801243v1
2001-10-29
Damping of inhomogeneities in neutralino dark matter
The lightest supersymmetric particle, most likely the neutralino, might account for a large fraction of dark matter in the Universe. We show that the primordial spectrum of density fluctuations in neutralino cold dark matter (CDM) has a sharp cut-off due to two damping mechanisms: collisional damping during the kinetic...
0110601v1
2002-08-03
Adiabatic Index of Dense Matter and Damping of Neutron Star Pulsations
The adiabatic index Gamma_1 for perturbations of dense matter is studied under various physical conditions which can prevail in neutron star cores. The dependence of Gamma_1 on the composition of matter (in particular, on the presence of hyperons), on the stellar pulsation amplitude, and on the baryon superfluidity is ...
0208078v1
2003-01-07
Damping of Neutron Star Shear Modes by Superfluid Friction
The forced motion of superfluid vortices in shear oscillations of rotating solid neutron star matter produces damping of the mode. A simple model of the unpinning and repinning processes is described, with numerical calculations of the consequent energy decay times. These are of the order of 1 s or more for typical ano...
0301112v1