publicationDate
stringlengths
1
2.79k
title
stringlengths
1
36.5k
abstract
stringlengths
1
37.3k
id
stringlengths
9
47
2023-05-26
Sphaleron rate from a modified Backus-Gilbert inversion method
We compute the sphaleron rate in quenched QCD for a temperature $T \simeq 1.24~T_c$ from the inversion of the Euclidean lattice time correlator of the topological charge density. We explore and compare two different strategies: one follows a new approach proposed in this study and consists in extracting the rate from f...
2305.17120v2
2023-07-21
Visibility graph-based covariance functions for scalable spatial analysis in nonconvex domains
We present a new method for constructing valid covariance functions of Gaussian processes over irregular nonconvex spatial domains such as water bodies, where the geodesic distance agrees with the Euclidean distance only for some pairs of points. Standard covariance functions based on geodesic distances are not positiv...
2307.11941v2
2023-08-23
Consistency of common spatial estimators under spatial confounding
This paper addresses the asymptotic performance of popular spatial regression estimators on the task of estimating the effect of an exposure on an outcome in the presence of an unmeasured spatially-structured confounder. This setting is often referred to as "spatial confounding." We consider spline models, Gaussian pro...
2308.12181v1
2023-09-19
Stochastic control of the Landau-Lifshitz-Gilbert equation
We consider the stochastic Landau-Lifshitz-Gilbert equation in dimension 1. A control process is added to the effective field. We show the existence of a weak martingale solution for the resulting controlled equation. The proof uses the classical Faedo-Galerkin approximation, along with the Jakubowski version of the Sk...
2309.10260v1
2023-10-18
Parallel-in-Time Integration of the Landau-Lifshitz-Gilbert Equation with the Parallel Full Approximation Scheme in Space and Time
Speeding up computationally expensive problems, such as numerical simulations of large micromagnetic systems, requires efficient use of parallel computing infrastructures. While parallelism across space is commonly exploited in micromagnetics, this strategy performs poorly once a minimum number of degrees of freedom pe...
2310.11819v1
2023-12-29
Chebyshev and Backus-Gilbert reconstruction for inclusive semileptonic $B_{(s)}$-meson decays from Lattice QCD
We present a study on the nonperturbative calculation of observables for inclusive semileptonic decays of $B_{(s)}$ mesons using lattice QCD. We focus on the comparison of two different methods to analyse the lattice data of Euclidean correlation functions, specifically Chebyshev and Backus-Gilbert approaches. This typ...
2312.17401v1
2024-02-22
Gilbert-Varshamov Bound for Codes in $L_1$ Metric using Multivariate Analytic Combinatorics
Analytic combinatorics in several variables refers to a suite of tools that provide sharp asymptotic estimates for certain combinatorial quantities. In this paper, we apply these tools to determine the Gilbert--Varshamov lower bound on the rate of optimal codes in $L_1$ metric. Several different code spaces are analyze...
2402.14712v1
2024-02-28
Embodied Supervision: Haptic Display of Automation Command to Improve Supervisory Performance
A human operator using a manual control interface has ready access to their own command signal, both by efference copy and proprioception. In contrast, a human supervisor typically relies on visual information alone. We propose supplying a supervisor with a copy of the operators command signal, hypothesizing improved p...
2402.18707v1
2024-03-14
Quantum analog of Landau-Lifshitz-Gilbert dynamics
The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog of the LL dynamics has been proposed in [Phys. Rev. Lett. 110, 147201 (2013)], the corresponding quantum version of LLG remains unknown. Here, we pro...
2403.09255v1
2024-03-15
Identification and estimation of mediational effects of longitudinal modified treatment policies
We demonstrate a comprehensive semiparametric approach to causal mediation analysis, addressing the complexities inherent in settings with longitudinal and continuous treatments, confounders, and mediators. Our methodology utilizes a nonparametric structural equation model and a cross-fitted sequential regression techn...
2403.09928v1
2024-03-22
Two-scale Analysis for Multiscale Landau-Lifshitz-Gilbert Equation: Theory and Numerical Methods
This paper discusses the theory and numerical method of two-scale analysis for the multiscale Landau-Lifshitz-Gilbert equation in composite ferromagnetic materials. The novelty of this work can be summarized in three aspects: Firstly, the more realistic and complex model is considered, including the effects of the exch...
2403.14957v1
2020-11-30
Role of Compressive Viscosity and Thermal Conductivity on the Damping of Slow Waves in the Coronal Loops With and Without Heating-Cooling Imbalance
In the present paper, we derive a new dispersion relation for slow magnetoacoustic waves invoking the effect of thermal conductivity, compressive viscosity, radiation and unknown heating term along with the consideration of heating cooling imbalance from linearized MHD equations. We solve the general dispersion relatio...
2011.14519v2
1999-08-20
The ac-Driven Motion of Dislocations in a Weakly Damped Frenkel-Kontorova Lattice
By means of numerical simulations, we demonstrate that ac field can support stably moving collective nonlinear excitations in the form of dislocations (topological solitons, or kinks) in the Frenkel-Kontorova (FK) lattice with weak friction, which was qualitatively predicted by Bonilla and Malomed [Phys. Rev. B{\bf 43}...
9908292v1
2003-06-19
Quantum model of phonon transport and heat conductivity in carbon nanoclusters and nanotubes
A complex approach phonon quantum discrete model (PQDM) was developed to describe dynamics, kinetics and statistics of phonons in carbon nanostructures with zero-chirality of both zig-zag and armchair geometry. The model allows include into the pure phonon problem existing interaction with others subsystems: electrons,...
0306503v1
2005-02-11
A Weakly Nonlinear Analysis of Impulsively-Forced Faraday Waves
Parametrically-excited surface waves, forced by a periodic sequence of delta-function impulses, are considered within the framework of the Zhang-Vi\~nals model (J. Fluid Mech. 1997). The exact impulsive-forcing results, in the linear and weakly nonlinear regimes, are compared with numerical results for sinusoidal and m...
0502025v1
2007-06-25
Toward faithful templates for non-spinning binary black holes using the effective-one-body approach
We present an accurate approximation of the full gravitational radiation waveforms generated in the merger of non-eccentric systems of two non-spinning black holes. Utilizing information from recent numerical relativity simulations and the natural flexibility of the effective-one-body (EOB) model, we extend the latter ...
0706.3732v3
2011-08-21
Time-Dependent Behavior of Lyman$α$ Photon Transfer in High Redshift Optically Thick Medium
With Monte Carlo simulation method, we investigate the time dependent behavior of Ly$\alpha$ photon transfer in optically thick medium of the concordance $\Lambda$CDM universe. At high redshift, the Ly$\alpha$ photon escaping from optically thick medium has a time scale as long as the age of the luminous object, or eve...
1108.4162v1
2011-09-03
Magnetic Fields Effects on the Electronic Conduction Properties of Molecular Ring Structures
While mesoscopic conducting loops are sensitive to external magnetic fields, as seen by observations of the Aharonov-Bohm (AB) effect in such structures, the field needed to observe the AB periodicity in small molecular rings is unrealistically large. The present study aims to identify conditions under which magnetic f...
1109.0619v1
2012-04-01
Resonance Broadening and Heating of Charged Particles in Magnetohydrodynamic Turbulence
The heating, acceleration, and pitch-angle scattering of charged particles by MHD turbulence are important in a wide range of astrophysical environments, including the solar wind, accreting black holes, and galaxy clusters. We simulate the interaction of high-gyrofrequency test particles with fully dynamical simulation...
1204.0155v2
2012-07-18
Quasinormal-mode spectrum of Kerr black holes and its geometric interpretation
There is a well-known, intuitive geometric correspondence between high-frequency QNMs of Schwarzschild black holes and null geodesics that reside on the light-ring : the real part of the mode's frequency relates to the geodesic's orbital frequency, and the imaginary part of the frequency corresponds to the Lyapunov exp...
1207.4253v1
2013-03-18
Sensitivity analysis of a time-delayed thermo-acoustic system via an adjoint-based approach
We apply adjoint-based sensitivity analysis to a time-delayed thermo-acoustic system: a Rijke tube containing a hot wire. We calculate how the growth rate and frequency of small oscillations about a base state are affected either by a generic passive control element in the system (the structural sensitivity analysis) o...
1303.4267v2
2013-07-12
Detection of Lyβauto-correlations and Lyα-Lyβ cross-correlations in BOSS Data Release 9
The Lyman-$\beta$ forest refers to a region in the spectra of distant quasars that lies between the rest-frame Lyman-$\beta$ and Lyman-$\gamma$ emissions. The forest in this region is dominated by a combination of absorption due to resonant Ly$\alpha$ and Ly$\beta$ scattering. When considering the 1D Ly$\beta$ forest i...
1307.3403v4
2013-12-20
Stability Boundaries for Resonant Migrating Planet Pairs
Convergent migration allows pairs of planet to become trapped into mean motion resonances. Once in resonance, the planets' eccentricities grow to an equilibrium value that depends on the ratio of migration time scale to the eccentricity damping timescale, $K=\tau_a/\tau_e$, with higher values of equilibrium eccentricit...
1312.6099v1
2014-04-10
Electromagnetic effects in the pion dispersion relation at finite temperature
We investigate the charged-neutral pion self-energy difference at finite temperature. Within Chiral Perturbation Theory we extend previous analysis in the chiral and soft pion limits. Our analysis with physical masses leads to additional contributions for temperatures typical of a meson gas, including a momentum-depend...
1404.2746v3
2014-11-10
Nonlinear Dynamics of Particles Excited by an Electric Curtain
The use of the electric curtain (EC) has been proposed for manipulation and control of particles in various applications. The EC studied in this paper is called the 2-phase EC, which consists of a series of long parallel electrodes embedded in a thin dielectric surface. The EC is driven by an oscillating electric poten...
1411.2492v1
2015-04-20
On the Riesz basis property of root vectors system for $2 \times 2$ Dirac type operators
The paper is concerned with the Riesz basis property of a boundary value problem associated in $L^2[0,1] \otimes \mathbb{C}^2$ with the following $2 \times 2$ Dirac type equation $$ L y = -i B^{-1} y' + Q(x) y = \lambda y, \quad B = \begin{pmatrix} b_1 & 0 \\ 0 & b_2 \end{pmatrix}, \quad y = \begin{pmatrix} y_1 \\ y_2 ...
1504.04954v2
2015-10-14
Fermi surface versus Fermi sea contributions to intrinsic anomalous and spin Hall effects of multiorbital metals in the presence of Coulomb interaction and spin-Coulomb drag
Anomalous Hall effect (AHE) and spin Hall effect (SHE) are fundamental phenomena, and their potential for application is great. However, we understand the interaction effects unsatisfactorily, and should have clarified issues about the roles of the Fermi sea term and Fermi surface term of the conductivity of the intrin...
1510.03988v5
2016-05-02
Cosmic Galaxy-IGM HI Relation at ${\it{z}}\sim 2-3$ Probed in the COSMOS/UltraVISTA $1.6$ deg$^2$ Field
We present spatial correlations of galaxies and IGM HI in the COSMOS/UltraVISTA 1.62 deg$^2$ field. Our data consist of 13,415 photo-$z$ galaxies at $z\sim2-3$ with $K_s<23.4$ and the Ly$\alpha$ forest absorptions in the background quasar spectra selected from SDSS data with no signature of damped Ly$\alpha$ system con...
1605.00379v3
2016-10-19
New scenario of turbulence theory and wall-bounded turbulence: Theoretical significance
General scenario of turbulence theory is proposed and applied to streaky wall-bounded turbulence. This scenario introduces a new field of transverse waves. Significance of the theory rests on a mathematical theorem associated with the conservation law of current flux, expressed in a form of 4d physical space-time repre...
1610.05975v2
2016-11-22
The cross-correlation between 21cm intensity mapping maps and the Lyman-alpha forest in the post-reionization era
We investigate the cross-correlation signal between 21cm intensity mapping maps and the Lyman-alpha forest in the fully non-linear regime using state-of-the-art hydrodynamic simulations. The cross-correlation signal between these fields can provide a coherent and comprehensive picture of the neutral hydrogen (HI) conte...
1611.07527v2
2017-02-02
Bouncing on Titan: Motion of the Huygens Probe in the Seconds After Landing
While landing on Titan, several instruments onboard Huygens acquired measurements that indicate the probe did not immediately come to rest. Detailed knowledge of the probe's motion can provide insight into the nature of Titan's surface. Combining accelerometer data from the Huygens Atmospheric Structure Instrument (HAS...
1702.00667v1
2017-06-26
Parsing spatiotemporal dynamical stability in ECoG during seizure onset, propagation, and termination
Understanding brain dynamics in epilepsy is critical for establishing rigorous control objectives that enable new therapeutic methods to mitigate seizure occurrence. In multichannel electrocorticography (ECoG) recordings acquired in 21 subjects during a total of 94 seizures, we apply dynamical systems stability analysi...
1706.08202v1
2017-10-05
Cross section alignment of polycyclic aromatic hydrocarbons by anisotropic radiation
We study the effect of anisotropic radiation illumination on the alignment of polycyclic aromatic hydrocarbons (PAHs) and report that cross-sectional mechanism of alignment earlier considered in terms of gas-grain interactions can also be efficient for the photon-grain interaction. We demonstrate this by first calculat...
1710.01835v2
2018-06-01
Kinetic Model for Stochastic Heating in the INCA Discharge
A novel electron heating mechanism based on periodically structured vortex fields induced in a plane was first proposed in 2014 [U. Czarnetzki and Kh. Tarnev, Physics of Plasmas 21, 123508 (2014)]. This theoretical concept has now been realized in an experiment which confirms efficient collisionless heating in such arr...
1806.00505v2
2019-01-09
Wave heating in gravitationally stratified coronal loops in the presence of resistivity and viscosity
In recent years, coronal loops have been the focus of studies related to the damping of different magnetohydrodynamic (MHD) surface waves and their connection with coronal seismology and wave heating. For a better understanding of wave heating, we need to take into account the effects of different dissipation coefficie...
1901.02676v2
2019-01-31
Analysis and active control of geometrically nonlinear responses of smart FG porous plates with graphene nanoplatelets reinforcement based on Bézier extraction of NURBS
In this paper, we propose an effective computational approach to analyze and active control of geometrically nonlinear responses of functionally graded (FG) porous plates with graphene nanoplatelets (GPLs) reinforcement integrated with piezoelectric layers. The key concept behind this work is to utilize isogeometric an...
1902.10806v2
2019-04-18
Cosmic-ray transport from AMS-02 B/C data: benchmark models and interpretation
This article aims at establishing new benchmark scenarios for Galactic cosmic-ray propagation in the GV-TV rigidity range, based on fits to the AMS-02 B/C data with the USINE v3.5 propagation code. We employ a new fitting procedure, cautiously taking into account data systematic error correlations in different rigidity...
1904.08917v2
2019-05-06
Formation and decay of eddy currents generated by crossed surface waves
The mass-transport induced by crossed surface waves consists of the Stokes and Euler contributions which are very different in nature. The first contribution is a generalization of Stokes drift for a plane wave in ideal fluid and the second contribution arises due to the fluid viscosity and it is excited by a force app...
1905.01875v2
2019-10-30
A priori bounds for the $Φ^4$ equation in the full sub-critical regime
We derive a priori bounds for the $\Phi^4$ equation in the full sub-critical regime using Hairer's theory of regularity structures. The equation is formally given by \begin{equation} \label{e}(\partial_t-\Delta)\phi = -\phi^3 + \infty \phi +\xi, \tag{$\star$} \end{equation} where the term $+\infty \phi$ represents infi...
1910.13854v2
2019-11-18
Wave measurements from ship mounted sensors in the Arctic marginal ice zone
Increased research interest and economic activity in the Arctic raise the need for new observations of sea ice dynamics. Remote sensing as well as mathematical and numerical models of wave propagation in sea ice would benefit from more in situ data for validation. This study presents wave measurements in the marginal i...
1911.07612v2
2020-08-02
Phase Diagram, Stability and Magnetic Properties of Nonlinear Excitations in Spinor Bose-Einstein Condensates
We present the phase diagram, the underlying stability and magnetic properties as well as the dynamics of nonlinear solitary wave excitations arising in the distinct phases of a harmonically confined spinor $F=1$ Bose-Einstein condensate. Particularly, it is found that nonlinear excitations in the form of dark-dark-bri...
2008.00475v3
2021-02-18
On stochastic heating and its phase-space signatures in low-$β$ kinetic turbulence
We revisit the theory of stochastic heating of ions and investigate its phase-space signatures in kinetic turbulence of relevance to low-$\beta$ portions of the solar wind. We retain a full scale-dependent approach in our treatment, and consider the case in which electric-field fluctuations can be described by a genera...
2102.09654v2
2021-06-16
Accurate and efficient hydrodynamic analysis of structures with sharp edges by the Extended Finite Element Method (XFEM): 2D studies
Achieving accurate numerical results of hydrodynamic loads based on the potential-flow theory is very challenging for structures with sharp edges, due to the singular behavior of the local-flow velocities. In this paper, we introduce the Extended Finite Element Method (XFEM) to solve fluid-structure interaction problem...
2106.08620v2
2021-06-25
Validity of point-mass model in off-resonance dynamic atomic force microscopy
The quantitative measurement of viscoelasticity of nano-scaleentities is an important goal of nanotechnology research and there is considerable progress with advent of dynamic Atomic Force Microscopy. The hydrodynamics of cantilever, the force sensor in AFM measurements, plays a pivotal role in quantitative estimates o...
2106.13631v1
2021-11-20
Current noise and Keldysh vertex function of an Anderson impurity in the Fermi liquid regime
We present a complete microscopic Fermi-liquid description for next-to-leading order transport through an Anderson impurity under a finite bias voltage $V$. It is applicable to multilevel quantum dots without particle-hole or time-reversal symmetry, and is constructed based on the nonequilibrium Keldysh formalism, taki...
2111.10483v2
2021-12-01
Numerical Study of Cosmic Ray Confinement through Dust Resonant Drag Instabilities
We investigate the possibility of cosmic ray (CR) confinement by charged dust grains through resonant drag instabilities (RDIs). We perform magnetohydrodynamic particle-in-cell simulations of magnetized gas mixed with charged dust and cosmic rays, with the gyro-radii of dust and GeV CRs on $\sim\mathrm{AU}$ scales full...
2112.00752v2
2022-03-09
A comparison of variational upwinding schemes for geophysical fluids, and their application to potential enstrophy conserving discretisations
Methods for upwinding the potential vorticity in a compatible finite element discretisation of the rotating shallow water equations are studied. These include the well-known anticipated potential vorticity method (APVM), streamwise upwind Petrov-Galerkin (SUPG) method, and a recent approach where the trial functions ar...
2203.04629v3
2022-03-26
Ion Alfvén velocity fluctuations and implications for the diffusion of streaming cosmic rays
The interstellar medium (ISM) of star-forming galaxies is magnetized and turbulent. Cosmic rays (CRs) propagate through it, and those with energies from $\sim\,\rm{GeV} - \rm{TeV}$ are likely subject to the streaming instability, whereby the wave damping processes balances excitation of resonant ionic Alfv\'en waves by...
2203.13952v3
2022-06-24
Data-driven reduced order models using invariant foliations, manifolds and autoencoders
This paper explores how to identify a reduced order model (ROM) from a physical system. A ROM captures an invariant subset of the observed dynamics. We find that there are four ways a physical system can be related to a mathematical model: invariant foliations, invariant manifolds, autoencoders and equation-free models...
2206.12269v3
2022-10-23
Tidally excited gravity waves in the cores of solar-type stars: resonances and critical-layer formation
We simulate the propagation and dissipation of tidally induced nonlinear gravity waves in the cores of solar-type stars. We perform hydrodynamical simulations of a previously developed Boussinesq model using a spectral-element code to study the stellar core as a wave cavity that is periodically forced at the outer boun...
2210.12880v2
1993-06-22
Weakly Damped Modes in Star Clusters and Galaxies
A perturber may excite a coherent mode in a star cluster or galaxy. If the stellar system is stable, it is commonly assumed that such a mode will be strongly damped and therefore of little practical consequence other than redistributing momentum and energy deposited by the perturber. This paper demonstrates that this a...
9306020v1
1997-12-03
On the Evolution of Damped Lyman Alpha Systems to Galactic Disks
The mean metallicity of the thick disk of the Galaxy is 0.5 dex higher than that of the damped Lyman alpha systems. This has been interpreted to argue that stars in the former do not arise out of gas in the latter. Using new metallicity and H I column-density data we show the metal-rich damped systems do contain suffic...
9712050v1
1998-10-23
Chemical Abundances of the Damped Lya Systems at z>1.5
We present chemical abundance measurements for 19 damped lya systems observed with HIRES on the 10m W.M. Keck Telescope. Our principal goal is to investigate the abundance patterns of the damped systems and thereby determine the underlying physical processes which dominate their chemical evolution. We place particular ...
9810381v1
2002-04-03
The role of damped Alfven waves on magnetospheric accretion models of young stars
We examine the role of Alfven wave damping in heating the plasma in the magnetic funnels of magnetospheric accretion models of young stars. We study four different damping mechanisms of the Alfven waves: nonlinear, turbulent, viscous-resistive and collisional. Two different possible origins for the Alfven waves are dis...
0204056v1
2009-09-19
Resonantly Damped Kink Magnetohydrodynamic Waves in a Partially Ionized Filament Thread
Transverse oscillations of solar filament and prominence threads have been frequently reported. These oscillations have the common features of being of short period (2-10 min) and being damped after a few periods. Kink magnetohydrodynamic (MHD) wave modes have been proposed as responsible for the observed oscillations,...
0909.3599v1
2009-10-15
Time damping of non-adiabatic magnetohydrodynamic waves in a partially ionized prominence plasma: Effect of helium
Prominences are partially ionized, magnetized plasmas embedded in the solar corona. Damped oscillations and propagating waves are commonly observed. These oscillations have been interpreted in terms of magnetohydrodynamic (MHD) waves. Ion-neutral collisions and non-adiabatic effects (radiation losses and thermal conduc...
0910.2883v1
2009-12-21
The effect of longitudinal flow on resonantly damped kink oscillations
The most promising mechanism acting towards damping the kink oscillations of coronal loops is resonant absorption. In this context most of previous studies neglected the effect of the obvious equilibrium flow along magnetic field lines. The flows are in general sub-Alfv\'enic and hence comparatively slow. Here we inves...
0912.4136v1
2010-07-12
Seismology of Standing Kink Oscillations of Solar Prominence Fine Structures
We investigate standing kink magnetohydrodynamic (MHD) oscillations in a prominence fine structure modeled as a straight and cylindrical magnetic tube only partially filled with the prominence material, and with its ends fixed at two rigid walls representing the solar photosphere. The prominence plasma is partially ion...
1007.1959v2
2012-10-30
Mode- and size-dependent Landau-Lifshitz damping in magnetic nanostructures: Evidence for non-local damping
We demonstrate a strong dependence of the effective damping on the nanomagnet size and the particular spin-wave mode that can be explained by the theory of intralayer transverse-spin-pumping. The effective Landau-Lifshitz damping is measured optically in individual, isolated nanomagnets as small as 100 nm. The measurem...
1210.8118v3
2012-11-21
Kinetic theory of surface plasmon polariton in semiconductor nanowires
Based on the semiclassical model Hamiltonian of the surface plasmon polariton and the nonequilibrium Green-function approach, we present a microscopic kinetic theory to study the influence of the electron scattering on the dynamics of the surface plasmon polariton in semiconductor nanowires. The damping of the surface ...
1211.5055v2
2013-11-12
Damping filter method for obtaining spatially localized solutions
Spatially localized structures are key components of turbulence and other spatio-temporally chaotic systems. From a dynamical systems viewpoint, it is desirable to obtain corresponding exact solutions, though their existence is not guaranteed. A damping filter method is introduced to obtain variously localized solution...
1311.2792v2
2014-09-19
Highly confined low-loss plasmons in graphene-boron nitride heterostructures
Graphene plasmons were predicted to possess ultra-strong field confinement and very low damping at the same time, enabling new classes of devices for deep subwavelength metamaterials, single-photon nonlinearities, extraordinarily strong light-matter interactions and nano-optoelectronic switches. While all of these grea...
1409.5674v1
2015-09-02
Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant
Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce sim...
1509.00877v1
2016-02-02
Forward Modelling of Propagating Slow Waves in Coronal Loops and Their Frequency-Dependent Damping
Propagating slow waves in coronal loops exhibit a damping which depends upon the frequency of the waves. In this study we aim to investigate the relationship of the damping length (L$_d$) with the frequency of the propagating wave. We present a 3-D coronal loop model with uniform density and temperature and investigate...
1602.00787v1
2016-05-11
Damping of prominence longitudinal oscillations due to mass accretion
We study the damping of longitudinal oscillations of a prominence thread caused by the mass accretion. In this model we considered a thin curved magnetic tube filled with the plasma. The parts of the tube at the two sides of the thread are filled with hot rarefied plasma. We assume that there are flows of rarefied plas...
1605.03376v1
2016-11-17
Inductive detection of field-like and damping-like AC inverse spin-orbit torques in ferromagnet/normal metal bilayers
Functional spintronic devices rely on spin-charge interconversion effects, such as the reciprocal processes of electric field-driven spin torque and magnetization dynamics-driven spin and charge flow. Both damping-like and field-like spin-orbit torques have been observed in the forward process of current-driven spin to...
1611.05798v2
2016-12-30
Spectroscopic evidence of Alfvén wave damping in the off-limb solar corona
We investigate off-limb active region and quiet Sun corona using spectroscopic data. Active region is clearly visible in several spectral lines formed in the temperature range of 1.1--2.8 MK. We derive electron number density using line ratio method, and non-thermal velocity in the off-limb region up to the distance of...
1612.09551v2
2017-01-04
Controlling plasmon modes and damping in buckled two-dimensional material open systems
Full ranges of both hybrid plasmon-mode dispersions and their damping are studied systematically by our recently developed mean-field theory in open systems involving a conducting substrate and a two-dimensional (2D) material with a buckled honeycomb lattice, such as silicene, germanene, and a group \rom{4} dichalcogen...
1701.01084v1
2017-04-05
Stimulated Brillouin scattering behaviors in different species ignition hohlraum plasmas in high-temperature and high-density region
The presence of multiple ion species can add additional branches to the IAW dispersion relation and change the Landau damping significantly. Different IAW modes excited by stimulated Brillouin scattering (SBS) and different SBS behaviors in several typical ignition hohlraum plasmas in the high-temperature and high-dens...
1704.02317v1
2017-06-29
Resonant Absorption of Axisymmetric Modes in Twisted Magnetic Flux Tubes
It has been shown recently that magnetic twist and axisymmetric MHD modes are ubiquitous in the solar atmosphere and therefore, the study of resonant absorption for these modes have become a pressing issue as it can have important consequences for heating magnetic flux tubes in the solar atmosphere and the observed dam...
1706.09665v1
2017-08-16
Damping of an oscillating scalar field indirectly coupled to a thermal bath
The damping process of a homogeneous oscillating scalar field that indirectly interacts with a thermal bath through a mediator field is investigated over a wide range of model parameters. We consider two types of mediator fields, those that can decay to the thermal bath and those that are individually stable but pair a...
1708.04865v2
2018-09-14
Continuous and discrete damping reduction for systems with quadratic interaction
We study the connection between Lagrangian and Hamiltonian descriptions of closed/open dynamics, for a collection of particles with quadratic interaction (closed system) and a sub-collection of particles with linear damping (open system). We consider both continuous and discrete versions of mechanics. We define the Dam...
1809.05532v1
2019-03-02
Complex Stiffness Model of Physical Human-Robot Interaction: Implications for Control of Performance Augmentation Exoskeletons
Human joint dynamic stiffness plays an important role in the stability of performance augmentation exoskeletons. In this paper, we consider a new frequency domain model of the human joint dynamics which features a complex value stiffness. This complex stiffness consists of a real stiffness and a hysteretic damping. We ...
1903.00704v4
2020-05-31
Optimal decay rates of the compressible Euler equations with time-dependent damping in $\mathbb R^n$: (II) over-damping case
This paper is concerned with the multi-dimensional compressible Euler equations with time-dependent over-damping of the form $-\frac{\mu}{(1+t)^\lambda}\rho\boldsymbol u$ in $\mathbb R^n$, where $n\ge2$, $\mu>0$, and $\lambda\in[-1,0)$. This continues our previous work dealing with the under-damping case for $\lambda\i...
2006.00403v1
2020-07-07
Nonlinear viscoelastic isolation for seismic vibration mitigation
The aim of this paper is to assess the effectiveness of nonlinear viscoelastic damping in controlling base-excited vibrations. Specifically, the focus is on investigating the robustness of the nonlinear base isolation performance in controlling the system response due to a wide set of possible excitation spectra. The d...
2007.04378v1
2021-01-20
Damped perturbations in stellar systems: Genuine modes and Landau-damped waves
This research was stimulated by the recent studies of damping solutions in dynamically stable spherical stellar systems. Using the simplest model of the homogeneous stellar medium, we discuss nontrivial features of stellar systems. Taking them into account will make it possible to correctly interpret the results obtain...
2101.08287v2
2021-03-10
Dynamical Pose Estimation
We study the problem of aligning two sets of 3D geometric primitives given known correspondences. Our first contribution is to show that this primitive alignment framework unifies five perception problems including point cloud registration, primitive (mesh) registration, category-level 3D registration, absolution pose ...
2103.06182v3
2021-04-13
Apparent nonlinear damping triggered by quantum fluctuations
Nonlinear damping, the change in damping rate with the amplitude of oscillations plays an important role in many electrical, mechanical and even biological oscillators. In novel technologies such as carbon nanotubes, graphene membranes or superconducting resonators, the origin of nonlinear damping is sometimes unclear....
2104.06464v2
2023-07-26
Improving frequency response with synthetic damping available from fleets of distributed energy resources
With the increasing use of renewable generation in power systems, responsive resources will be necessary to support primary frequency control in future low-inertia/under-damped power systems. Flexible loads can provide fast-frequency response services if coordinated effectively. However, practical implementations of su...
2307.14498v1
2023-12-11
Possible Contamination of the Intergalactic Medium Damping Wing in ULAS J1342+0928 by Proximate Damped Ly$α$ Absorption
The red damping wing from neutral hydrogen in the intergalactic medium is a smoking-gun signal of ongoing reionization. One potential contaminant of the intergalactic damping wing signal is dense gas associated with foreground galaxies, which can give rise to proximate damped Ly$\alpha$ absorbers. The Ly$\alpha$ imprin...
2312.06747v1
2024-02-13
Forecasts for Constraining Lorentz-violating Damping of Gravitational Waves from Compact Binary Inspirals
Violation of Lorentz symmetry can result in two distinct effects in the propagation of the gravitational waves (GWs). One is a modified dispersion relation and another is a frequency-dependent damping of GWs. While the former has been extensively studied in the literature, in this paper we concentrate on the frequency-...
2402.08240v1
2024-03-13
Thermal Hall effect incorporating magnon damping in localized spin systems
We propose a theory for thermal Hall transport mediated by magnons to address the impact of their damping resulting from magnon-magnon interactions in insulating magnets. This phenomenon is anticipated to be particularly significant in systems characterized by strong quantum fluctuations, exemplified by spin-1/2 system...
2403.08478v1
2024-04-02
A recipe for eccentricity and inclination damping for partial gap opening planets in 3D disks
In a previous paper we showed that, like the migration speed, the eccentricity damping efficiency is modulated linearly by the depth of the partial gap a planet carves in the disk surface density profile, resulting in less efficient $e$-damping compared to the prescription commonly used in population synthesis works. H...
2404.02247v1
2009-08-21
Surface Alfven Wave Damping in a 3D Simulation of the Solar Wind
Here we investigate the contribution of surface Alfven wave damping to the heating of the solar wind in minima conditions. These waves are present in regions of strong inhomogeneities in density or magnetic field (e. g., the border between open and closed magnetic field lines). Using a 3-dimensional Magnetohydrodynamic...
0908.3146v1
2017-11-21
Determination of spin Hall effect and spin diffusion length of Pt from self-consistent fitting of damping enhancement and inverse spin-orbit torque measurements
Understanding the evolution of spin-orbit torque (SOT) with increasing heavy-metal thickness in ferromagnet/normal metal (FM/NM) bilayers is critical for the development of magnetic memory based on SOT. However, several experiments have revealed an apparent discrepancy between damping enhancement and damping-like SOT r...
1711.07654v2
2019-09-19
Nonlinear energy loss in the oscillations of coated and uncoated bubbles: Role of thermal, radiation damping and encapsulating shell at various excitation pressures
A simple generalized model (GM) for coated bubbles accounting for the effect of compressibility of the liquid is presented. The GM was then coupled with nonlinear ODEs that account for the thermal effects. Starting with mass and momentum conservation equations for a bubbly liquid and using the GM, nonlinear pressure de...
1909.08793v1
2020-11-20
The effect of magnetic field on the damping of slow waves in the solar corona
Slow magnetoacoustic waves are routinely observed in astrophysical plasma systems such as the solar corona. As a slow wave propagates through a plasma, it modifies the equilibrium quantities of density, temperature, and magnetic field. In the corona and other plasma systems, the thermal equilibrium is comprised of a ba...
2011.10437v1
1997-11-25
Abundances of Heavy Elements and CO Molecules in High Redshift Damped Lyman-alpha Galaxies
Damped Lyman-alpha systems seen in spectra of background quasars are generally thought to represent high redshift counterparts of present-day galaxies. We summarize observations of heavy element abundances in damped Lyman-alpha systems. The results of a systematic search for CO and C II* absorption in 17 damped Lyman-a...
9711298v1
1997-12-05
Magnetohydrodynamics in the Early Universe and the Damping of Non-linear Alfven Waves
The evolution and viscous damping of cosmic magnetic fields in the early universe, is analysed. Using the fact that the fluid, electromagnetic, and shear viscous energy-momentum tensors are all conformally invariant, the evolution is transformed from the expanding universe setting into that in flat spacetime. Particula...
9712083v1
2001-08-09
Are Simulations of CDM Consistent with Galactic-Scale Observations at High Redshift?
We compare new observations on the kinematic characteristics of the damped Lya systems against results from numerical SPH simulations to test the predictions of hierarchical galaxy formation. This exercise is particularly motivated by recent numerical results on the cross-section of damped Lya systems. Our analysis foc...
0108154v1
2003-03-19
Distinct Abundance Patterns in Multiple Damped Ly-alpha Galaxies: Evidence for Truncated Star Formation?
(abridged) Following our previous work on metal abundances of a double damped Ly-alpha system with a line-of-sight separation ~2000 km/s (Ellison & Lopez 2001), we present VLT UVES abundances of 3 new systems spanning a total of \~6000 km/s at z~2.5 toward the southern QSO CTQ247. These abundances are supplemented with...
0303441v1
2003-05-16
New Damped Lya Metallicities from ESI Spectroscopy of Five Palomar Sky Survey Quasars
This paper presents chemical abundance measurements for 12 new z>3 damped Lya systems discovered toward five quasars from the Palomar Sky Survey. We determine HI column densities from profile fits to the observed damped Lya profiles and measure ionic column densities and limits for all observed metal-line transitions. ...
0305313v1
2006-07-06
Ekman layer damping of r-modes revisited
We investigate the damping of neutron star r-modes due to the presence of a viscous boundary (Ekman) layer at the interface between the crust and the core. Our study is motivated by the possibility that the gravitational-wave driven instability of the inertial r-modes may become active in rapidly spinning neutron stars...
0607105v2
1997-11-05
Hydrodynamic damping in trapped Bose gases
Griffin, Wu and Stringari have derived the hydrodynamic equations of a trapped dilute Bose gas above the Bose-Einstein transition temperature. We give the extension which includes hydrodynamic damping, following the classic work of Uehling and Uhlenbeck based on the Chapman-Enskog procedure. Our final result is a close...
9711036v4
1998-05-01
Finite Temperature Perturbation Theory for a Spatially Inhomogeneous Bose-condensed Gas
We develop a finite temperature perturbation theory (beyond the mean field) for a Bose-condensed gas and calculate temperature-dependent damping rates and energy shifts for Bogolyubov excitations of any energy. The theory is generalized for the case of excitations in a spatially inhomogeneous (trapped) Bose-condensed g...
9805015v2
2003-10-18
Experiment and Dynamic Simulations of Radiation Damping of Laser-polarized liquid 129Xe at low magnetic field in a flow system
Radiation damping is generally observed when the sample with high spin concentration and high gyro-magnetic ratio is placed in a high magnetic field. However, we firstly observed liquid state 129Xe radiation damping using laser-enhanced nuclear polarization at low magnetic field in a flow system in which the polarizati...
0310435v1
2004-03-25
XMCD characterization of rare-earth dopants in Ni$_{81}$Fe$_{19}$(50nm): microscopic basis of engineered damping
We present direct evidence for the contribution of local orbital moments to the damping of magnetization precession in magnetic thin films. Using x-ray magnetic circular dichroism (XMCD) characterization of rare-earth (RE) M$_{4,5}$ edges in Ni$_{81}$Fe$_{19}$ doped with $<$ 2% Gd and Tb, we show that the enhancement o...
0403627v1
2005-02-08
Landau Damping of Spin Waves in Trapped Boltzmann Gases
A semiclassical method is used to study Landau damping of transverse pseudo-spin waves in harmonically trapped ultracold gases in the collisionless Boltzmann limit. In this approach, the time evolution of a spin is calculated numerically as it travels in a classical orbit through a spatially dependent mean field. This ...
0502189v1
2005-06-01
Landau damping of Bogoliubov excitations in optical lattices at finite temperature
We study the damping of Bogoliubov excitations in an optical lattice at finite temperatures. For simplicity, we consider a Bose-Hubbard tight-binding model and limit our analysis to the lowest excitation band. We use the Popov approximation to calculate the temperature dependence of the number of condensate atoms $n^{\...
0506016v1
2006-06-15
Landau damping: instability mechanism of superfluid Bose gases moving in optical lattices
We investigate Landau damping of Bogoliubov excitations in a dilute Bose gas moving in an optical lattice at finite temperatures. Using a 1D tight-binding model, we explicitly obtain the Landau damping rate, the sign of which determines the stability of the condensate. We find that the sign changes at a certain condens...
0606398v2