publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2019-09-14 | Measurement-Based Wide-Area Damping of Inter-Area Oscillations based on MIMO Identification | Interconnected power grid exhibits oscillatory response after a disturbance
in the system. One such type of oscillations, the inter-area oscillations has
the oscillation frequency in the range of 0.1 to 1 Hz. The damping of
inter-area oscillations is difficult with local controllers, but it can be
achieved using a Wide... | 1909.06687v1 |
2020-02-07 | Engineering Co$_2$MnAl$_x$Si$_{1-x}$ Heusler compounds as a model system to correlate spin polarization, intrinsic Gilbert damping and ultrafast demagnetization | Engineering of magnetic materials for developing better spintronic
applications relies on the control of two key parameters: the spin polarization
and the Gilbert damping responsible for the spin angular momentum dissipation.
Both of them are expected to affect the ultrafast magnetization dynamics
occurring on the femt... | 2002.02686v1 |
2020-03-16 | Spin-orbit torques originating from bulk and interface in Pt-based structures | We investigated spin-orbit torques in prototypical Pt-based spintronic
devices. We found that, in Pt/Ni and Pt/Fe bilayers, the damping-like torque
efficiency depends on the thickness of the Pt layer. We also found that the
damping-like torque efficiency is almost identical in the Pt/Ni and Pt/Fe
bilayers despite the s... | 2003.07271v2 |
2020-03-23 | Heat-like and wave-like lifespan estimates for solutions of semilinear damped wave equations via a Kato's type lemma | In this paper we study several semilinear damped wave equations with
"subcritical" nonlinearities, focusing on demonstrating lifespan estimates for
energy solutions. Our main concern is on equations with scale-invariant damping
and mass. Under different assumptions imposed on the initial data, lifespan
estimates from a... | 2003.10578v1 |
2020-09-03 | Dynamics of magnetic collective modes in the square and triangular lattice Mott insulators at finite temperature | We study the equilibrium dynamics of magnetic moments in the Mott insulating
phase of the Hubbard model on the square and triangular lattice. We rewrite the
Hubbard interaction in terms of an auxiliary vector field and use a recently
developed Langevin scheme to study its dynamics. A thermal `noise', derivable
approxim... | 2009.01833v2 |
2020-09-15 | Classification of the mechanisms of wave energy dissipation in the nonlinear oscillations of coated and uncoated bubbles | Acoustic waves are dissipated when they pass through bubbly media.
Dissipation by bubbles takes place through thermal damping (Td), radiation
damping (Rd) and damping due to the friction of the liquid (Ld) and friction of
the coating (Cd). Knowledge of the contributions of the Td, Rd, Ld and Cd
during nonlinear bubble ... | 2009.07380v1 |
2020-11-18 | The effect of redshift degeneracy and the damping effect of viscous medium on the information extracted from gravitational wave signals | Considering the cosmological redshift $z_c$ , the mass of GW source extracted
from GW signal is $1+z_c$ times larger than its intrinsic value, and distance
between detector and GW source should be regarded as luminosity distance.
However, besides cosmological redshift, there are other kinds of redshifts
should be consi... | 2011.09169v2 |
2020-12-28 | On the Efficacy of Friction Damping in the Presence of Nonlinear Modal Interactions | This work addresses friction-induced modal interactions in jointed
structures, and their effects on the passive mitigation of vibrations by means
of friction damping. Under the condition of (nearly) commensurable natural
frequencies, the nonlinear character of friction can cause so-called nonlinear
modal interactions. ... | 2101.03232v1 |
2021-06-30 | Origin of Nonlinear Damping due to Mode Coupling in Auto-Oscillatory Modes Strongly Driven by Spin-Orbit Torque | We investigate the physical origin of nonlinear damping due to mode coupling
between several auto-oscillatory modes driven by spin-orbit torque in
constricted Py/Pt heterostructures by examining the dependence of
auto-oscillation on temperature and applied field orientation. We observe a
transition in the nonlinear dam... | 2107.00150v2 |
2021-07-15 | On the long-time behavior for a damped Navier-Stokes-Bardina model | In this paper, we consider a damped Navier-Stokes-Bardina model posed on the
whole three-dimensional. These equations have an important physical motivation
and they arise from some oceanic model. From the mathematical point of view,
they write down as the well-know Navier-Stokes equations with an additional
nonlocal op... | 2107.07070v2 |
2021-07-17 | Plasmon-Exciton Coupling Effect on Plasmon Damping | Plasmon decay via the surface or interface is a critical process for
practical energy conversion and plasmonic catalysis. However, the relationship
between plasmon damping and the coupling between the plasmon and 2D materials
is still unclear. The spectral splitting due to plasmon-exciton interaction
impedes the conven... | 2107.08230v1 |
2021-10-12 | Outflows in the presence of cosmic rays and waves with cooling | Plasma outflow from a gravitational potential well with cosmic rays and
self-excited Alfv\'en waves with cooling and wave damping is studied in the
hydrodynamics regime. We study outflows in the presence of cosmic ray and
Alfv\'en waves including the effect of cooling and wave damping. We seek
physically allowable stea... | 2110.06170v1 |
2021-11-19 | Finite time extinction for a class of damped Schr{ö}dinger equations with a singular saturated nonlinearity | We present some sharper finite extinction time results for solutions of a
class of damped nonlinear Schr{\"o}dinger equations when the nonlinear damping
term corresponds to the limit cases of some ``saturating non-Kerr law''
$F(|u|^2)u=\frac{a}{\varepsilon+(|u|^2)^\alpha}u,$ with $a\in\mathbb{C},$
$\varepsilon\geqslant... | 2111.10136v2 |
2022-01-26 | Effect of Chiral Damping on the dynamics of chiral domain walls and skyrmions | Friction plays an essential role in most physical processes that we
experience in our everyday life. Examples range from our ability to walk or
swim, to setting boundaries of speed and fuel efficiency of moving vehicles. In
magnetic systems, the displacement of chiral domain walls (DW) and skyrmions
(SK) by Spin Orbit ... | 2201.10742v1 |
2022-01-27 | A Study on Monte Carlo simulation of the radiation environment above GeV at the DAMPE orbit | The Dark Matter Particle Explorer (DAMPE) has been undergoing a stable
on-orbit operation for more than 6 years and acquired observation of over 11
billion events. And a better understanding of the overall radiation environment
on the DAMPE orbit is crucial for both simulation data production and flight
data analysis. ... | 2201.11364v1 |
2022-05-10 | Nonlinear damping quantification from phase-resonant tests under base excitation | The present work addresses the experimental identification of
amplitude-dependent modal parameters (modal frequency, damping ratio, Fourier
coefficients of periodic modal oscillation). Phase-resonant testing has emerged
as an important method for this task, as it substantially reduces the amount of
data required for th... | 2205.04735v1 |
2022-09-22 | Neutrino Fast Flavor Pendulum. Part 2: Collisional Damping | In compact astrophysical objects, the neutrino density can be so high that
neutrino-neutrino refraction can lead to fast flavor conversion of the kind
$\nu_e \bar\nu_e \leftrightarrow \nu_x \bar\nu_x$ with $x=\mu,\tau$, depending
on the neutrino angle distribution. Previously, we have shown that in a
homogeneous, axisy... | 2209.11235v3 |
2022-10-12 | Second order two-species systems with nonlocal interactions: existence and large damping limits | We study the mathematical theory of second order systems with two species,
arising in the dynamics of interacting particles subject to linear damping, to
nonlocal forces and to external ones, and resulting into a nonlocal version of
the compressible Euler system with linear damping. Our results are limited to
the $1$ s... | 2210.06162v1 |
2022-10-12 | Stability of the Néel quantum critical point in the presence of Dirac fermions | We investigate the stability of the N\'eel quantum critical point of
two-dimensional quantum antiferromagnets, described by a non-linear $\sigma$
model (NL$\sigma$M), in the presence of a Kondo coupling to $N_f$ flavours of
two-component Dirac fermion fields. The long-wavelength order parameter
fluctuations are subject... | 2210.06577v3 |
2022-11-13 | Damping analysis of Floating Offshore Wind Turbine (FOWT): a new control strategy reducing the platform vibrations | In this paper, the coupled dynamics of the floating platform and the WTG
rotor is analysed. In particular, the damping is explicitly derived from the
coupled equations of rotor and floating platform. The analysis of the damping
leads to the study of the instability phenomena and it derives the explicit
conditions that ... | 2211.10362v1 |
2022-11-22 | Universal Dynamics of Damped-Driven Systems: The Logistic Map as a Normal Form for Energy Balance | Damped-driven systems are ubiquitous in engineering and science. Despite the
diversity of physical processes observed in a broad range of applications, the
underlying instabilities observed in practice have a universal characterization
which is determined by the overall gain and loss curves of a given system. The
unive... | 2211.11748v1 |
2023-01-23 | Optimal Inter-area Oscillation Damping Control: A Transfer Deep Reinforcement Learning Approach with Switching Control Strategy | Wide-area damping control for inter-area oscillation (IAO) is critical to
modern power systems. The recent breakthroughs in deep learning and the broad
deployment of phasor measurement units (PMU) promote the development of
datadriven IAO damping controllers. In this paper, the damping control of IAOs
is modeled as a M... | 2301.09321v1 |
2023-03-15 | Blow-up and decay for a class of variable coefficient wave equation with nonlinear damping and logarithmic source | In this paper, we consider the long time behavior for the solution of a class
of variable coefficient wave equation with nonlinear damping and logarithmic
source. The existence and uniqueness of local weak solution can be obtained by
using the Galerkin method and contraction mapping principle. However, the long
time be... | 2303.08629v1 |
2023-04-13 | Centralised Multimode Power Oscillation Damping Controller for Photovoltaic Plants with Communication Delay Compensation | Low-frequency oscillations are an inherent phenomena in transmission networks
and renewable energy plants should be configured to damp them. Commonly, a
centralised controller is used in PV plants to coordinate PV generators via
communication channels. However, the communication systems of PV plants
introduce delays of... | 2304.06415v1 |
2023-05-09 | Glassy heat capacity from overdamped phasons and a hypothetical phason-induced superconductivity in incommensurate structures | Phasons are collective low-energy modes that appear in disparate condensed
matter systems such as quasicrystals, incommensurate structures, fluctuating
charge density waves, and Moir\'e superlattices. They share several
similarities with acoustic phonon modes, but they are not protected by any
exact translational symme... | 2305.05407v2 |
2023-08-03 | Flavor-wave theory with quasiparticle damping at finite temperatures: Application to chiral edge modes in the Kitaev model | We propose a theoretical framework to investigate elementary excitations at
finite temperatures within a localized electron model that describes the
interactions between multiple degrees of freedom, such as quantum spin models
and Kugel-Khomskii models. Thus far, their excitation structures have been
mainly examined us... | 2308.01711v1 |
2024-02-13 | Investigating the Effect of Noise on the Training Performance of Hybrid Quantum Neural Networks | In this paper, we conduct a comprehensively analyze the influence of
different quantum noise gates, including Phase Flip, Bit Flip, Phase Damping,
Amplitude Damping, and the Depolarizing Channel, on the performance of HyQNNs.
Our results reveal distinct and significant effects on HyQNNs training and
validation accuraci... | 2402.08523v1 |
2024-03-03 | Magnonic $\varphi$ Josephson Junctions and Synchronized Precession | There has been a growing interest in non-Hermitian physics. One of its main
goals is to engineer dissipation and to explore ensuing functionality. In
magnonics, the effect of dissipation due to local damping on magnon transport
has been explored. However, the effects of non-local damping on the magnonic
analog of the J... | 2403.01625v1 |
2024-04-09 | A Frequency-Domain Beamforming Procedure for Extracting Rayleigh Wave Attenuation Coefficients and Small-Strain Damping Ratio from 2D Ambient Noise Array Measurements | The small-strain damping ratio plays a crucial role in assessing the response
of soil deposits to earthquake-induced ground motions and general dynamic
loading. The damping ratio can theoretically be inverted for after extracting
frequency-dependent Rayleigh wave attenuation coefficients from wavefields
collected durin... | 2404.06650v1 |
1997-01-17 | Evidence for Rotation in the Galaxy at z=3.15 Responsible for a Damped Lyman-alpha Absorption System in the Spectrum of Q2233+1310 | Proof of the existence of a significant population of normal disk galaxies at
redshift z>2 would have profound implications for theories of structure
formation and evolution. We present evidence based on Keck HIRES observations
that the damped Lyman-alpha absorber at z=3.15 toward the quasar Q2233+1310 may
well be such... | 9701116v2 |
1997-04-11 | The Metallicity of High Redshift Galaxies: The Abundance of Zinc in 34 Damped Lyman Alpha Systems from z = 0.7 to 3.4 | We report new observations of ZnII and CrII absorption lines in 10 damped
\lya systems (DLAs), mostly at redshift $z_{abs} \simgt 2.5$ . By combining
these results with those from our earlier survey (Pettini et al. 1994) and
other recent data, we construct a sample of 34 measurements (or upper limits)
of the Zn abundan... | 9704102v1 |
1997-04-17 | On the Kinematics of the Damped Lyman Alpha Protogalaxies | We present the first results of an ongoing program to investigate the
kinematic characteristics of high redshift damped lya systems. Because damped
lya systems are widely believed to be the progenitors of current massive
galaxies, an analysis of their kinematic history allows a direct test of galaxy
formation scenarios... | 9704169v2 |
2000-11-20 | H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6 | Despite previous intensive ground-based imaging and spectroscopic campaigns
and wide-band HST imaging of the z=0.927 QSO 3C336 field, the galaxy that hosts
the damped Ly-alpha system along this line-of-sight has eluded detection. We
present a deep narrow-band H-alpha image of the field of this z=0.656 damped
Ly-alpha a... | 0011374v2 |
2005-08-17 | The SDSS Damped Lya Survey: Data Release 3 | We present the results from a damped Lya survey of the Sloan Digital Sky
Survey, Data Release 3 based on over 500 new damped Lya systems at z>2.2. We
measure the HI column density distribution f(N) and its zeroth and first
moments (the incidence l(X) and gas mass-density O_dla of damped Lya systems,
respectively) as a ... | 0508361v1 |
2010-03-11 | Damping of MHD turbulence in partially ionized gas and the observed difference of velocities of neutrals and ions | Theoretical and observational studies on the turbulence of the interstellar
medium developed fast in the past decades. The theory of supersonic magnetized
turbulence, as well as the understanding of projection effects of observed
quantities, are still in progress. In this work we explore the characterization
of the tur... | 1003.2346v1 |
2011-09-07 | Weakly collisional Landau damping and three-dimensional Bernstein-Greene-Kruskal modes: New results on old problems | Landau damping and Bernstein-Greene-Kruskal (BGK) modes are among the most
fundamental concepts in plasma physics. While the former describes the
surprising damping of linear plasma waves in a collisionless plasma, the latter
describes exact undamped nonlinear solutions of the Vlasov equation. There does
exist a relati... | 1109.1353v1 |
2012-11-06 | Torsional Alfvén waves in solar partially ionized plasma: effects of neutral helium and stratification | Ion-neutral collisions may lead to the damping of Alfven waves in
chromospheric and prominence plasmas. Neutral helium atoms enhance the damping
in certain temperature interval, where the ratio of neutral helium and neutral
hydrogen atoms is increased. Therefore, the height-dependence of ionization
degrees of hydrogen ... | 1211.1348v2 |
2013-05-16 | Application of vibration-transit theory to distinct dynamic response for a monatomic liquid | We examine the distinct part of the density autocorrelation function Fd(q,t),
also called the intermediate scattering function, from the point of view of the
vibration-transit (V-T) theory of monatomic liquid dynamics. A similar study
has been reported for the self part, and we study the self and distinct parts
separat... | 1305.3954v2 |
2013-09-16 | Two-atom system as a nano-antenna for mode switching and light routing | We determine how a system composed of two nonidentical two-level atoms with
different resonance frequencies and different damping rates could work as a
nano-antenna for controlled mode switching and light routing. We calculate the
angular distribution of the emitted field detected in a far-field zone of the
system incl... | 1309.3924v1 |
2015-04-01 | Landau damping of Gardner solitons in a dusty bi-ion plasma | The effects of linear Landau damping on the nonlinear propagation of
dust-acoustic solitary waves (DASWs) are studied in a collisionless
unmagnetized dusty plasma with two species of positive ions. The extremely
massive, micron-seized, cold and negatively charged dust particles are
described by fluid equations, whereas... | 1504.00089v2 |
2017-03-09 | Material developments and domain wall based nanosecond-scale switching process in perpendicularly magnetized STT-MRAM cells | We investigate the Gilbert damping and the magnetization switching of
perpendicularly magnetized FeCoB-based free layers embedded in tunnel junctions
adequate for spin-torque operated memories. We study the influence of the boron
content in MgO / FeCoB /Ta systems alloys on their Gilbert damping after
crystallization a... | 1703.03198v3 |
2017-07-18 | Explanations of the DAMPE high energy electron/positron spectrum in the dark matter annihilation and pulsar scenarios | Many studies have shown that either the nearby astrophysical source or dark
matter (DM) annihilation/decay is required to explain the origin of high energy
cosmic ray (CR) $e^\pm$, which are measured by many experiments, such as PAMELA
and AMS-02. Recently, the Dark Matter Particle Explorer (DAMPE) collaboration
has re... | 1707.05664v2 |
2018-06-27 | In-flight performance of the DAMPE silicon tracker | DAMPE (DArk Matter Particle Explorer) is a spaceborne high-energy cosmic ray
and gamma-ray detector, successfully launched in December 2015. It is designed
to probe astroparticle physics in the broad energy range from few GeV to 100
TeV. The scientific goals of DAMPE include the identification of possible
signatures of... | 1806.10355v1 |
2018-10-30 | Effect of Landau damping on ion acoustic solitary waves in a multi-species collisionless unmagnetized plasma consisting of nonthermal and isothermal electrons | A Korteweg-de Vries (KdV) equation including the effect of Landau damping is
derived to study the propagation of weakly nonlinear and weakly dispersive ion
acoustic waves in a collisionless unmagnetized plasma consisting of warm
adiabatic ions and two different species of electrons at different
temperatures. The hotter... | 1810.12739v1 |
2019-03-28 | Improving convergence of volume penalised fluid-solid interactions | We analyse and improve the volume-penalty method, a simple and versatile way
to model objects in fluid flows. The volume-penalty method is a kind of
fictitious-domain method that approximates no-slip boundary conditions with
rapid linear damping inside the object. The method can then simulate complex,
moving objects in... | 1903.11914v4 |
2019-06-12 | Study of Alfven Eigenmodes stability in plasma with multiple NBI driven energetic particle specie | The aim of this study is to analyze the destabilization of Alfven Eigenmodes
(AE) by multiple energetic particles (EP) species in DIII-D and LHD discharges.
We use the reduced MHD equations to describe the linear evolution of the
poloidal flux and the toroidal component of the vorticity in a full 3D system,
coupled wit... | 1906.05701v1 |
2020-06-08 | Stochastic re-acceleration and magnetic-field damping in Tycho's supernova remnant | A number of studies suggest that shock acceleration with particle feedback
and very efficient magnetic-field amplification combined with Alfv\'{e}nic
drift are needed to explain the rather soft radio spectrum and the narrow rims
observed for Tycho's SNR. We show that the broadband spectrum of Tycho's SNR
can alternativ... | 2006.04832v1 |
2021-02-23 | Influence of Ion-Neutral Damping on the Cosmic-Ray Streaming Instability: Magnetohydrodynamic Particle-in-cell Simulations | We explore the physics of the gyro-resonant cosmic ray streaming instability
(CRSI) including the effects of ion-neutral (IN) damping. This is the main
damping mechanism in (partially-ionized) atomic and molecular gas, which are
the primary components of the interstellar medium (ISM) by mass. Limitation of
CRSI by IN d... | 2102.11878v3 |
2022-06-17 | Quantum Dynamics of Magnetic Skyrmions: Consistent Path Integral Formulation | We present a path integral formalism for the intrinsic quantum dynamics of
magnetic skyrmions coupled to a thermal background of magnetic fluctuations.
Upon promoting the skyrmion's collective coordinate $\boldsymbol{R}$ to a
dynamic variable and integrating out the magnonic heat bath, we derive the
generalized equatio... | 2206.08532v2 |
2024-02-05 | Revisiting the role of cosmic-ray driven Alfvén waves in pre-existing magnetohydrodynamic turbulence. I. Turbulent damping rates and feedback on background fluctuations | Alfv\'en waves (AWs) excited by the cosmic-ray (CR) streaming instability
(CRSI) are a fundamental ingredient for CR confinement. The effectiveness of
self-confinement relies on a balance between CRSI growth rate and damping
mechanisms acting on quasi-parallel AWs excited by CRs. One relevant mechanism
is the so-called... | 2402.02901v1 |
2006-10-24 | Logical contradictions of Landau damping | Landau damping/growing at boundary condition of excitation of a harmonic wave
in collisionless ion-electron-neutrals plasma contradicts to the law of energy
conservation of a wave damping/growing in space. There is also no criterion of
a choice either damping or growing solution in difference from always
non-damping in... | 0610220v67 |
2000-05-31 | The afterglow of the short/intermediate-duration gamma-ray burst GRB 000301C: A jet at z=2.04 | We present Ulysses and NEAR data from the detection of the short or
intermediate duration (2 s) gamma-ray burst GRB000301C (2000 March 1.41 UT).
The gamma-ray burst (GRB) was localised by the Inter Planetary Network (IPN)
and RXTE to an area of 50 arcmin^2. A fading optical counterpart was
subsequently discovered with ... | 0005609v2 |
2011-05-16 | A Measurement of the Damping Tail of the Cosmic Microwave Background Power Spectrum with the South Pole Telescope | We present a measurement of the angular power spectrum of the cosmic
microwave background (CMB) using data from the South Pole Telescope (SPT). The
data consist of 790 square degrees of sky observed at 150 GHz during 2008 and
2009. Here we present the power spectrum over the multipole range 650 < ell <
3000, where it i... | 1105.3182v2 |
2016-10-07 | The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters | We present the temperature and polarization angular power spectra measured by
the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time
data collected during 2013-14 using two detector arrays at 149 GHz, from 548
deg$^2$ of sky on the celestial equator. We use these spectra, and the spectra
measured w... | 1610.02360v1 |
1995-02-16 | Lyman alpha Emission from High-Redshift Galaxies | We summarise the results of a deep search for Lyman alpha emission from
star-forming regions associated with damped Lyman alpha absorption systems and
conclude that the Lyman alpha luminosity of high redshift galaxies is generally
less than 10^(42) erg/s . We also present a newly discovered case, in the field
of the QS... | 9502076v1 |
1995-10-12 | Limits on diffusive shock acceleration in dense and incompletely ionised media | The limits imposed on diffusive shock acceleration by upstream ion-neutral
Alfven wave damping, and by ionisation and Coulomb losses of low energy
particles, are calculated. Analytic solutions are given for the steady upstream
wave excitation problem with ion-neutral damping and the resulting escaping
upstream flux cal... | 9510066v2 |
1995-11-28 | Damping of GRR instability by direct URCA reactions | The role of direct URCA reactions in damping of the gravitational radiation
driven instability is discussed. The temperature at which bulk viscosity
suppresses completely this instability is calculated.
The results are obtained analytically using recent calculations performed in
the case of bulk viscosity due to the ... | 9511136v1 |
1997-10-31 | Abundances in Damped Lyman-alpha Systems and Chemical Evolution of High Redshift Galaxies | Recent abundance measurements in damped Lyman-alpha galaxies, supplemented
with unpublished Keck observations, are discussed. The metallicity distribution
with cosmic time is examined for clues about the degree of enrichment, the
onset of initial star formation, and the nature of the galxies. The relative
abundances of... | 9710370v1 |
1998-05-08 | Exploring the Damped Lyman-alpha Clouds with AXAF | The High Energy Transmission Grating (HETG) Spectrometer on the Advanced
X-ray Astrophysics Facility (AXAF) (scheduled for launch in August, 1998) will
provide a new tool for the study of absorption in the X-ray spectra of high
redshift quasars due to the material along the line of sight. In this paper we
try to explor... | 9805110v1 |
1998-05-28 | Photon Damping of Waves in Accretion Disks | MHD turbulence is generally believed to have two important functions in
accretion disks: it transports angular momentum outward, and the energy in its
shortest wavelength modes is dissipated into the heat that the disks radiate.
In this paper we examine a pair of mechanisms which may play an important role
in regulatin... | 9805358v1 |
1998-06-11 | Damping of differential rotation in neutron stars | We derive the transport relaxation times for quasiparticle-vortex scattering
processes via nuclear force, relevant for the damping of differential rotation
of superfluids in the quantum liquid core of a neutron star. The proton
scattering off the neutron vortices provides the dominant resistive force on
the vortex latt... | 9806156v1 |
1999-03-10 | Elemental abundances at early times: the nature of Damped Lyman-alpha systems | The distribution of element abundances with redshift in Damped Ly-alpha (DLA)
systems can be adequately reproduced by the same model reproducing the halo and
disk components of the Milky Way Galaxy at different galactocentric distances:
DLA systems are well represented by normal spiral galaxies in their early
evolution... | 9903150v1 |
1999-07-26 | Are Damped Ly-alpha Systems Large, Galactic Disks ? | The hypothesis that the Damped Ly-alpha systems (DLAs) are large, galactic
disks (Milky Way sized) is tested by confronting predictions of models of the
formation and evolution of (large) disk galaxies with observations, in
particular the Zinc abundance distribution with neutral hydrogen column density
found for DLAs. ... | 9907349v1 |
1999-11-25 | Probing Solar Convection | In the solar convection zone acoustic waves are scattered by turbulent sound
speed fluctuations. In this paper the scattering of waves by convective cells
is treated using Rytov's technique. Particular care is taken to include
diffraction effects which are important especially for high-degree modes that
are confined to... | 9911469v1 |
1999-12-14 | The Gas Reservoir for present day Galaxies : Damped Ly-alpha Absorption Systems | We present results from an ongoing search for galaxy counterparts of a
subgroup of Quasar Absorption Line Systems called Damped Ly-alpha Absorbers
(DLAs). DLAs have several characteristics that make them essential in the
process of understanding how galaxies formed in the early universe and evolved
to the galaxies we s... | 9912268v1 |
2000-06-22 | Nuclear Reaction Rates in a Plasma: The Effect of Highly Damped Modes | The fluctuation-dissipation theorem is used to evaluate the screening factor
of nuclear reactions due to the electromagnetic fluctuations in a plasma. We
show that the commonly used Saltpeter factor is obtained if only fluctuations
near the plasma eigenfrequency are assumed to be important (\omega \sim
\omega_{pe}\ll T... | 0006326v1 |
2001-01-13 | Measuring Feedback in Damped Lyman Alpha Systems | We measure feedback (heating rates) in damped Lyman alpha systems from the
cooling rate of the neutral gas. Since cooling occurs through [C II] 158 micron
emission, we infer cooling from C II^{*} 1335.7 absorption lines detected with
HIRES on the Keck I telescope. The inferred heating rates are about 30 times
lower tha... | 0101218v1 |
2001-04-18 | The First Detection of Cobalt in a Damped Lyman Alpha System | We present the first ever detection of Cobalt in a Damped Lyman Alpha system
(DLA) at z = 1.92. In addition to providing important clues to the star
formation history of these high redshift galaxies, we discuss how studying the
Co abundance in DLAs may also help to constrain models of stellar
nucleosynthesis in a regim... | 0104301v1 |
2001-05-09 | Nuclear reaction rates and energy in stellar plasmas : The effect of highly damped modes | The effects of the highly damped modes in the energy and reaction rates in a
plasma are discussed. These modes, with wavenumbers $k \gg k_{D}$, even being
only weakly excited, with less than $k_{B}T$ per mode, make a significant
contribution to the energy and screening in a plasma. When the de Broglie
wavelength is muc... | 0105153v1 |
2001-07-03 | The HI Content and Extent of Low Surface Brightness Galaxies - Could LSB Galaxies be Responsible for Damped Ly-alpha Absorption? | Low surface brightness galaxies, those galaxies with a central surface
brightness at least one magnitude fainter than the night sky, are often not
included in discussions of extragalactic gas at z < 0.1. In this paper we
review many of the properties of low surface brightness galaxies, including
recent studies which in... | 0107064v1 |
2001-09-10 | H_2 molecules in damped systems | Damped Lyman alpha systems seen in the spectra of high-z QSOs arise in
high-density neutral gas in which molecular hydrogen (H_2) should be
conspicuous. Systematic searches to detect the H_2 lines redshifted into the
Lyman alpha forest at <3400\AA are now possible thanks to the unique
capabilities of UVES on the VLT. H... | 0109155v1 |
2001-10-23 | A scaling law of interstellar depletions as a tool for abundance studies of Damped Ly alpha systems | An analytical expression is presented that allows dust depletions to be
estimated in different types of interstellar environments, including Damped Ly
alpha systems. The expression is a scaling law of a reference depletion pattern
and takes into account the possibility that the dust chemical composition may
vary as a f... | 0110499v1 |
2002-09-23 | Outflows in Galaxies and Damped Ly-alpha System | Although quasar absorbers, and in particular Damped Lyman-alpha systems
(DLAs) have proven a valuable tool to study the early Universe, their exact
nature is so far poorly constrained. It has been suggested that outflows in
galaxies might account for at least part of the DLA population. Observational
evidences and mode... | 0209463v1 |
2004-03-15 | The Damping Wing of the Gunn-Peterson Absorption and Lyman-Alpha Emitters in the Pre-Reionization Era | We use a numerical simulation of cosmological reionization to estimate the
likelihood of detecting Lyman-alpha emitting galaxies during the
pre-reionization era. We show that it is possible to find galaxies even at z~9
that are barely affected by the dumping wing of the Gunn-Peterson absorption
from the neutral IGM out... | 0403345v1 |
2005-05-28 | Cosmic ray transport in MHD turbulence | Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call
for revisions in the picture of cosmic ray transport. In this paper we use
recently obtained scaling laws for MHD modes to obtain the scattering frequency
for cosmic rays. We account for the turbulence cutoff arising from both
collisional and... | 0505575v1 |
2005-06-22 | A Damped Ly-alpha Absorption-line System in an Apparent Void at Redshift 2.38 | We study the contents of an apparent void in the distribution of Ly-alpha
emitting galaxies at redshift 2.38. We show that this void is not empty, but
contains a damped Ly-alpha absorption-line system, seen in absorption against
background QSO 2138-4427. Imaging does not reveal any galaxy associated with
this absorptio... | 0506525v1 |
2005-08-08 | Fluorescence in damp air and comments on the radiative life time | Photon yields in damp air excited by an electron using a Sr90 $\beta$ source
are compared withthose in dry air. Water vapors considerably reduce the yields,
however, a further study is needed to evaluate the effects on the energy
estimation of ultrahigh-energy cosmic rays. The relation of fluorescence
efficiency to the... | 0508183v1 |
2006-08-17 | Electron thermal conductivity owing to collisions between degenerate electrons | We calculate the thermal conductivity of electrons produced by
electron-electron Coulomb scattering in a strongly degenerate electron gas
taking into account the Landau damping of transverse plasmons. The Landau
damping strongly reduces this conductivity in the domain of ultrarelativistic
electrons at temperatures belo... | 0608371v1 |
2006-09-19 | Dust, Metals and Diffuse Interstellar Bands in Damped Lyman Alpha Systems | Although damped Lyman alpha (DLA) systems are usually considered metal-poor,
it has been suggested that this could be due to observational bias against
metal-enriched absorbers. I review recent surveys to quantify the particular
issue of dust obscuration bias and demonstrate that there is currently no
compelling observ... | 0609530v1 |
2006-11-08 | Comments on Viscous Damping of Non-Adiabatic MHD Waves in an Unbounded Solar Coronal Plasma by Kumar and Kumar | Considering thermal conduction, compressive viscosity and optically thin
radiation as damping mechanisms for MHD waves, we derive a six-order general
dispersion relation. We point out a fundamental flaw in the derivation of
five-order dispersion relation by Kumar and Kumar (2006) who adopt as a basis
vector. The correc... | 0611252v2 |
2007-01-10 | Non-gaussianity in fluctuations from warm inflation | The scalar mode density perturbations in a the warm inflationary scenario are
analysed with a view to predicting the amount of non-gaussianity produced by
this scenario. The analysis assumes that the inflaton evolution is strongly
damped by the radiation, with damping terms that are temperature independent.
Entropy flu... | 0701302v2 |
1998-05-22 | WKB for a damped spin | The master equation for a damped spin well known from the theory of
superradiance, is written as a finite-difference equation and solved by a
WKB-like method. The propagator thus obtained looks like the van Vleck
propagator of a certain classical Hamiltonian system with one degree of
freedom. A new interpretation is pr... | 9805018v1 |
1998-11-04 | Cascades of energy and helicity in the GOY shell model of turbulence | The effect of extreme hyperviscous damping, $\nu k_n^p, p=\infty$ is studied
numerically in the GOY shell model of turbulence. It has resently been
demonstrated [Leveque and She, Phys. Rev. Lett, 75,2690 (1995)] that the
inertial range scaling in the GOY model is non-universal and depending on the
viscous damping. The ... | 9811009v1 |
1994-02-04 | Effects of Disorder in a Dilute Bose Gas | We discuss the effects of a weak random external potential on the properties
of the dilute Bose gas at zero temperature. The results recently obtained by
Huang and Meng for the depletion of the condensate and of the superfluid
density are recovered. Results for the shift of the velocity of sound as well
as for its damp... | 9402015v1 |
1997-02-13 | Comment on "Collective Excitations of a Bose-Einstein Condensate in a Magnetic Trap" | We calculate the damping rate of collective excitations for a nearly pure
Bose-Einstein condensate regarding the recent experiments in MIT [M.-O. Mews et
al, Phys. Rev. Lett. 77, 988 (1996)]. The decay time of collective excitations
obtained in our theoretical calculations agrees well with their experimental
result. We... | 9702122v1 |
1997-08-14 | Landau damping in dilute Bose gases | Landau damping in weakly interacting Bose gases is investigated by means of
perturbation theory. Our approach points out the crucial role played by
Bose-Einstein condensation and yields an explicit expression for the decay rate
of elementary excitations in both uniform and non uniform gases. Systematic
results are deri... | 9708104v1 |
1997-11-07 | Coulomb suppression of NMR coherence peak in fullerene superconductors | The suppressed NMR coherence peak in the fullerene superconductors is
explained in terms of the dampings in the superconducting state induced by the
Coulomb interaction between conduction electrons. The Coulomb interaction,
modelled in terms of the onsite Hubbard repulsion, is incorporated into the
Eliashberg theory of... | 9711060v2 |
1997-12-09 | The Sound of Sonoluminescence | We consider an air bubble in water under conditions of single bubble
sonoluminescence (SBSL) and evaluate the emitted sound field nonperturbatively
for subsonic gas-liquid interface motion. Sound emission being the dominant
damping mechanism, we also implement the nonperturbative sound damping in the
Rayleigh-Plesset e... | 9712097v1 |
1998-12-02 | Vortex lattice melting and the damping of the dHvA oscillations in the mixed state | Phase fluctuations in the superconducting order parameter, which are
responsible for the melting of the Abrikosov vortex lattice below the mean
field $H_{c2}$, are shown to dramatically enhance the scattering of
quasi-particles by the fluctuating pair potential, thus leading to enhanced
damping of the dHvA oscillations... | 9812040v1 |
1999-06-15 | Temperature-induced resonances and Landau damping of collective modes in Bose-Einstein condensed gases in spherical traps | Interaction between collective monopole oscillations of a trapped
Bose-Einstein condensate and thermal excitations is investigated by means of
perturbation theory. We assume spherical symmetry to calculate the matrix
elements by solving the linearized Gross-Pitaevskii equations. We use them to
study the resonances of t... | 9906214v1 |
1999-08-03 | Kinetic Theory of Collective Modes in Atomic Clouds above the Bose-Einstein Transition Temperature | We calculate frequencies and damping rates of the lowest collective modes of
a dilute Bose gas confined in an anisotropic trapping potential above the
Bose-Einstein transition temperature. From the Boltzmann equation with a
simplified collision integral we derive a general dispersion relation that
interpolates between ... | 9908043v1 |
1999-09-01 | Normal Fermi Liquid Behavior of Quasiholes in the Spin-Polaron Model for Copper Oxides | Based on the t-J model and the self-consistent Born approximation, the
damping of quasiparticle hole states near the Fermi surface is calculated in a
low doping regime. Renormalization of spin-wave excitations due to hole doping
is taken into account. The damping is shown to be described by a familiar form
$\text{Im}\S... | 9909020v1 |
1999-12-01 | Impurity relaxation mechanism for dynamic magnetization reversal in a single domain grain | The interaction of coherent magnetization rotation with a system of two-level
impurities is studied. Two different, but not contradictory mechanisms, the
`slow-relaxing ion' and the `fast-relaxing ion' are utilized to derive a system
of integro-differential equations for the magnetization. In the case that the
impurity... | 9912014v1 |
2000-02-16 | Dissipative dynamics of Bose condensates in optical cavities | We study the zero temperature dynamics of Bose-Einstein condensates in driven
high-quality optical cavities in the limit of large atom-field detuning. We
calculate the stationary ground state and the spectrum of coupled atom and
field mode excitations for standing wave cavities as well as for travelling
wave cavities. ... | 0002247v1 |
2000-09-13 | Oscillations of the superconducting order parameter in a ferromagnet | Planar tunneling spectroscopy reveals damped oscillations of the
superconducting order parameter induced into a ferromagnetic thin film by the
proximity effect. The oscillations are due to the finite momentum transfer
provided to Cooper pairs by the splitting of the spin up and down bands in the
ferromagnet. As a conse... | 0009192v1 |
2000-09-29 | Damping and revivals of collective oscillations in a finite-temperature model of trapped Bose-Einstein condensation | We utilize a two-gas model to simulate collective oscillations of a
Bose-Einstein condensate at finite temperatures. The condensate is described
using a generalized Gross-Pitaevskii equation, which is coupled to a thermal
cloud modelled by a Monte Carlo algorithm. This allows us to include the
collective dynamics of bo... | 0009468v1 |
2001-04-18 | Effective rate equations for the over-damped motion in fluctuating potentials | We discuss physical and mathematical aspects of the over-damped motion of a
Brownian particle in fluctuating potentials. It is shown that such a system can
be described quantitatively by fluctuating rates if the potential fluctuations
are slow compared to relaxation within the minima of the potential, and if the
positi... | 0104330v1 |
2001-09-05 | Spin Excitations in a Fermi Gas of Atoms | We have experimentally investigated a spin excitation in a quantum degenerate
Fermi gas of atoms. In the hydrodynamic regime the damping time of the
collective excitation is used to probe the quantum behavior of the gas. At
temperatures below the Fermi temperature we measure up to a factor of 2
reduction in the excitat... | 0109098v2 |
2001-10-09 | Freezing of a Stripe Liquid | The existence of a stripe-liquid phase in a layered nickelate,
La(1.725)Sr(0.275)NiO(4), is demonstrated through neutron scattering
measurements. We show that incommensurate magnetic fluctuations evolve
continuously through the charge-ordering temperature, although an abrupt
decrease in the effective damping energy is ... | 0110191v2 |
2001-12-13 | Magnon softening and damping in the ferromagnetic manganites due to orbital correlations | We present a theory for spin excitations in ferromagnetic metallic manganites
and demonstrate that orbital fluctuations have strong effects on the magnon
dynamics in the case these compounds are close to a transition to an orbital
ordered state. In particular we show that the scattering of the spin
excitations by low-l... | 0112252v2 |
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