publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2009-08-19 | Quantum Energy Teleportation with Electromagnetic Field: Discrete vs. Continuous Variables | It is well known that usual quantum teleportation protocols cannot transport
energy. Recently, new protocols called quantum energy teleportation (QET) have
been proposed, which transport energy by local operations and classical
communication with the ground states of many-body quantum systems. In this
paper, we compare... | 0908.2674v2 |
2009-08-25 | Designing materials for plasmonic systems | We use electronic structure calculations based upon density functional theory
to search for ideal plasmonic materials among the alkali noble intermetallics.
Importantly, we use density functional perturbation theory to calculate the
electron-phonon interaction and from there use a first order solution to the
Boltzmann ... | 0908.3707v1 |
2009-09-15 | Quantum critical points of Helical Fermi Liquids | Following our previous work, we study the quantum phase transitions which
spontaneously develop ferromagnetic spin order in helical fermi liquids which
breaks continuous spin-space rotation symmetry, with application to the edge
states of 3d topological band insulators. With finite fermi surface, the
critical point has... | 0909.2647v3 |
2009-09-25 | Evidence for Landau's critical velocity in superfluid helium nanodroplets from wave packet dynamics of attached potassium dimers | Femtosecond pump-probe spectroscopy has been used to study vibrational
dynamics of potassium dimers attached to superfluid helium nanodroplets.
Comparing the measured data with theoretical results based on dissipative
quantum dynamics we propose that the most important effect of the helium
environment is a general damp... | 0909.4691v1 |
2009-10-23 | Fragmentation of the photoabsorption strength in neutral and charged metal microclusters | The line shape of the plasma resonance in both neutral and charged small
sodium clusters is calculated. The overall properties of the multipeak
structure observed in the photoabsorption cross section of spherical Na_8 and
Na_20 neutral clusters can be understood in terms of Landau damping. Quantal
configurations are sh... | 0910.4576v1 |
2009-10-28 | Quantum Decoherence of Two Qubits | It is commonly stated that decoherence in open quantum systems is due to
growing entanglement with an environment. In practice, however, surprisingly
often decoherence may equally well be described by random unitary dynamics
without invoking a quantum environment at all. For a single qubit, for
instance, pure decoheren... | 0910.5364v1 |
2009-10-29 | System-reservoir dynamics of quantum and classical correlations | We address the system-reservoir dynamics of classical and quantum
correlations in the decoherence phenomenon, regarding a two qubit composite
system interacting with two independent environments. The most common noise
channels (amplitude damping, phase damping, bit flip, bit-phase flip, and phase
flip) was studied. By ... | 0910.5711v3 |
2009-11-04 | Nonlinear damping in a micromechanical oscillator | Nonlinear elastic effects play an important role in the dynamics of
microelectromechanical systems (MEMS). Duffing oscillator is widely used as an
archetypical model of mechanical resonators with nonlinear elastic behavior. In
contrast, nonlinear dissipation effects in micromechanical oscillators are
often overlooked. ... | 0911.0833v2 |
2009-11-04 | Solar-like oscillations in massive main-sequence stars. I. Asteroseismic signatures of the driving and damping regions | Motivated by the recent detection of stochastically excited modes in the
massive star V1449 Aql (Belkacem et al., 2009b), already known to be a $\beta$
Cephei, we theoretically investigate the driving by turbulent convection. By
using a full non-adiabatic computation of the damping rates, together with a
computation of... | 0911.0908v1 |
2009-11-11 | Ginzburg-Landau equation for dynamical four-wave mixing in gain nonlinear media with relaxation | We consider the dynamical degenerate four-wave mixing (FWM) model in a cubic
nonlinear medium including both the time relaxation of the induced nonlinearity
and the nonlocal coupling. The initial ten-dimensional FWM system can be
rewritten as a three-variable intrinsic system (namely the intensity pattern,
the amplitud... | 0911.2129v1 |
2009-12-10 | Bipartite quantum channels using multipartite cluster-type entangled coherent states | We propose a particular encoding for bipartite entangled states derived from
multipartite cluster-type entangled coherent states (CTECSs). We investigate
the effects of amplitude damping on the entanglement content of this bipartite
state, as well as its usefulness as a quantum channel for teleportation. We
find intere... | 0912.1949v2 |
2009-12-18 | Oscillatory transient regime in the forced dynamics of a spin torque nano-oscillator | We demonstrate that the transient non-autonomous dynamics of a spin torque
nano-oscillator (STNO) under a radio-frequency (rf) driving signal is
qualitatively different from the dynamics described by the Adler model. If the
external rf current $I_{rf}$ is larger than a certain critical value $I_{cr}$
(determined by the... | 0912.3650v1 |
2009-12-19 | Study of sdO models: mode trapping | We present the first description of mode trapping for sdO models. Mode
trapping of gravity modes caused by the He/H chemical transition is found for a
particular model, providing a selection effect for high radial order trapped
modes. Low- and intermediate-radial order {\em p}-modes (mixed modes with a
majority of node... | 0912.3911v1 |
2009-12-20 | Optimal Design of Fuzzy Based Power System Stabilizer Self Tuned by Robust Search Algorithm | In the interconnected power system network, instability problems are caused
mainly by the low frequency oscillations of 0.2 to 2.5 Hz. The supplementary
control signal in addition with AVR and high gain excitation systems are
provided by means of Power System Stabilizer (PSS). Conventional power system
stabilizers prov... | 0912.3960v2 |
2009-12-23 | Decoherence and Entanglement Dynamics in Fluctuating Fields | We study pure phase damping of two qubits due to fluctuating fields. As
frequently employed, decoherence is thus described in terms of random unitary
(RU) dynamics, i.e., a convex mixture of unitary transformations. Based on a
separation of the dynamics into an average Hamiltonian and a noise channel, we
are able to an... | 0912.4654v2 |
2010-01-02 | Distinguishing quantum channels via magic squares game | We study the effect of quantum memory in magic squares game when played in
quantum domain. We consider different noisy quantum channels and analyze their
influence on the magic squares quantum pseudo-telepathy game. We show that the
probability of success can be used to distinguish the quantum channels. It is
seen that... | 1001.0295v1 |
2010-01-06 | Freezing of spin dynamics and omega/T scaling in underdoped cuprates | The memory function approach to spin dynamics in doped antiferromagnetic
insulator combined with the assumption of temperature independent static spin
correlations and constant collective mode damping leads to omega/T scaling in a
broad range. The theory involving a non universal scaling parameter is used to
analyze re... | 1001.0837v1 |
2010-01-15 | Calculating Green Functions from Finite Systems | In calculating Green functions for interacting quantum systems numerically
one often has to resort to finite systems which introduces a finite size level
spacing. In order to describe the limit of system size going to infinity
correctly, one has to introduce an artificial broadening larger than the finite
size level di... | 1001.2750v1 |
2010-02-02 | Inertial Oscillations of Pinned Dislocations | Dislocation pinning plays a vital role in the plastic behaviour of a
crystalline solid. Here we report the first observation of the damped
oscillations of a mobile dislocation after it gets pinned at an obstacle in the
presence of a constant static shear load. These oscillations are found to be
inertial, instead of for... | 1002.0422v1 |
2010-02-03 | Nonlinear stability of viscous roll waves | Extending results of Oh--Zumbrun and Johnson--Zumbrun for parabolic
conservation laws, we show that spectral stability implies nonlinear stability
for spatially periodic viscous roll wave solutions of the one-dimensional St.
Venant equations for shallow water flow down an inclined ramp. The main new
issues to be overco... | 1002.0788v2 |
2010-02-05 | Damped-driven KdV and effective equation for long-time behaviour of its solutions | For the damped-driven KdV equation $$ \dot
u-\nu{u_{xx}}+u_{xxx}-6uu_x=\sqrt\nu \eta(t,x), x\in S^1, \int u dx\equiv
\int\eta dx\equiv0, $$ with $0<\nu\le1$ and smooth in $x$ white in $t$ random
force $\eta$, we study the limiting long-time behaviour of the KdV integrals of
motions $(I_1,I_2,...)$, evaluated along a so... | 1002.1294v1 |
2010-02-09 | Fate of non-Fermi liquid behavior in QED$_{3}$ at finite chemical potential | The damping rate of two-dimensional massless Dirac fermions exhibit non-Fermi
liquid behavior, $\propto \epsilon^{1/2}$, due to gauge field at zero
temperature and zero chemical potential. We study the fate of this behavior at
finite chemical potential. We fist calculate explicitly the temporal and
spatial components o... | 1002.1760v3 |
2010-02-18 | Direct Evidence for Two-Fluid Effects in Molecular Clouds | We present a combination of theoretical and simulation-based examinations of
the role of two-fluid ambipolar drift on molecular line widths. The dissipation
provided by ion-neutral interactions can produce a significant difference
between the widths of neutral molecules and the widths of ionic species,
comparable to th... | 1002.3443v1 |
2010-03-08 | Potential mechanical loss mechanisms in bulk materials for future gravitational wave detectors | Low mechanical loss materials are needed to further decrease thermal noise in
upcoming gravitational wave detectors. We present an analysis of the
contribution of Akhieser and thermoelastic damping on the experimental results
of resonant mechanical loss measurements. The combination of both processes
allows the fit of ... | 1003.1613v1 |
2010-03-31 | Non-Markovian master equation for a damped oscillator with time-varying parameters | We derive an exact non-Markovian master equation that generalizes the
previous work [Hu, Paz and Zhang, Phys. Rev. D {\bf 45}, 2843 (1992)] to damped
harmonic oscillators with time-varying parameters. This is achieved by
exploiting the linearity of the system and operator solution in Heisenberg
picture. Our equation go... | 1003.5975v1 |
2010-04-08 | Doppler cooling a microsphere | Doppler cooling the center-of-mass motion of an optically levitated
microsphere via the velocity dependent scattering force from narrow whispering
gallery mode (WGM) resonances is described. Light that is red detuned from the
WGM resonance can be used to damp the center-of-mass motion in a process
analogous to the Dopp... | 1004.1443v1 |
2010-05-17 | Concerning the statistics of cosmic magnetism | Magnetic fields appear to be a generic feature of the early universe and are
a natural source of secondary CMB non-Gaussianity. In recent years the
statistical nature of the stresses of a primordial magnetic field has been well
studied. In this paper we confirm and extend these studies at one- and
two-point level, and ... | 1005.2982v1 |
2010-05-20 | Line Solutions for the Euler and Euler-Poisson Equations with Multiple Gamma Law | In this paper, we study the Euler and Euler-Poisson equations in $R^{N}$,
with multiple $\gamma$-law for pressure function: \begin{equation}
P(\rho)=e^{s}\sum_{j=1}^{m}\rho^{\gamma_{j}}, \end{equation} where all
$\gamma_{i+1}>\gamma_{i}\geq1$, is the constants. The analytical line solutions
are constructed for the syst... | 1005.3651v1 |
2010-06-12 | Mechanical filtering in forced-oscillation of two coupled pendulums | Forced oscillation of a system composed of two pendulums coupled by a spring
in the presence of damping is investigated. In the steady state and within the
small angle approximation we solve the system equations of motion and obtain
the amplitudes and phases of in terms of the frequency of the sinusoidal
driving force.... | 1006.2475v1 |
2010-07-12 | Ferromagnetic Excitations in La$_{0.82}$Sr$_{0.18}$CoO$_{3}$ Observed Using Neutron Inelastic Scattering | Polarized neutron inelastic scattering has been used to measure spin
excitations in ferromagnetic La$_{0.82}$Sr$_{0.18}$CoO$_{3}$. The magnon
spectrum of these spin excitations is well defined at low energies but becomes
heavily damped at higher energies, and can be modeled using a quadratic
dispersion. We determined a... | 1007.1919v1 |
2010-07-28 | Minimization of phonon-tunneling dissipation in mechanical resonators | Micro- and nanoscale mechanical resonators have recently emerged as
ubiquitous devices for use in advanced technological applications, for example
in mobile communications and inertial sensors, and as novel tools for
fundamental scientific endeavors. Their performance is in many cases limited by
the deleterious effects... | 1007.4948v1 |
2010-08-05 | Linear and Non-Linear Landau Resonance of Kinetic Alfvén Waves: Consequences for Electron Distribution and Wave Spectrum in the Solar Wind | Kinetic Alfven wave turbulence in solar wind is considered and it is shown
that non-Maxwellian electron distribution function has a significant effect on
the dynamics of the solar wind plasmas. Linear Landau damping leads to the
formation of a plateau in the parallel electron distribution function which
diminishes the ... | 1008.0993v1 |
2010-08-11 | Theory for a dissipative droplet soliton excited by a spin torque nanocontact | A novel type of solitary wave is predicted to form in spin torque oscillators
when the free layer has a sufficiently large perpendicular anisotropy. In this
structure, which is a dissipative version of the conservative droplet soliton
originally studied in 1977 by Ivanov and Kosevich, spin torque counteracts the
dampin... | 1008.1898v1 |
2010-08-18 | Modulation stabilization of Bloch oscillations of two-component Bose-Einstein condensates in optical lattices | We study the Bloch oscillations (BOs) of two-component Bose-Einstein
condensates (BECs) trapped in spin-dependent optical lattices. Based on the
derived equations of motion of the wave packet in the basis of localized wave
functions of the lattice sites, the damping effect induced by the
intercomponent and intracompone... | 1008.3004v1 |
2010-08-19 | Josephson Coupling and Fiske Dynamics in Ferromagnetic Tunnel Junctions | We report on the fabrication of Nb/AlO_x/Pd_{0.82}Ni_{0.18}/Nb
superconductor/insulator/ferromagnetic metal/superconductor (SIFS) Josephson
junctions with high critical current densities, large normal resistance times
area products, high quality factors, and very good spatial uniformity. For
these junctions a transitio... | 1008.3341v1 |
2010-09-03 | A Simple Numerical Absorbing Layer Method in Elastodynamics | The numerical analysis of elastic wave propagation in unbounded media may be
difficult to handle due to spurious waves reflected at the model artificial
boundaries. Several sophisticated techniques such as nonreflecting boundary
conditions, infinite elements or absorbing layers (e.g. Perfectly Matched
Layers) lead to a... | 1009.0592v1 |
2010-09-09 | Modulation of waves due to charge-exchange collisions in magnetized partially ionized space plasma | A nonlinear time dependent fluid simulation model is developed that describes
the evolution of magnetohydrodynamic waves in the presence of collisional and
charge exchange interactions of a partially ionized plasma. The partially
ionized plasma consists of electrons, ions and a significant number of neutral
atoms. In o... | 1009.1859v1 |
2010-09-15 | A discontinuous Galerkin method for the Vlasov-Poisson system | A discontinuous Galerkin method for approximating the Vlasov-Poisson system
of equations describing the time evolution of a collisionless plasma is
proposed. The method is mass conservative and, in the case that piecewise
constant functions are used as a basis, the method preserves the positivity of
the electron distri... | 1009.3046v2 |
2010-10-03 | Measurement of damping and temperature: Precision bounds in Gaussian dissipative channels | We present a comprehensive analysis of the performance of different classes
of Gaussian states in the estimation of Gaussian phase-insensitive dissipative
channels. In particular, we investigate the optimal estimation of the damping
constant and reservoir temperature. We show that, for two-mode squeezed vacuum
probe st... | 1010.0442v1 |
2010-10-12 | Movers and shakers: Granular damping in microgravity | The response of an oscillating granular damper to an initial perturbation is
studied using experiments performed in microgravity and granular dynamics
mulations. High-speed video and image processing techniques are used to extract
experimental data. An inelastic hard sphere model is developed to perform
simulations and... | 1010.2343v1 |
2010-10-18 | K-shell photoionization of Na-like to Cl-like ions of Mg, Si, S, Ar, and Ca | We present $R$-matrix calculations of photoabsorption and photoionization
cross sections across the K-edge of Mg, Si, S, Ar, and Ca ions with more than
10 electrons. The calculations include the effects of radiative and Auger
damping by means of an optical potential. The wave functions are constructed
from single-elect... | 1010.3734v1 |
2010-10-19 | A possible signature of cosmic neutrino decoupling in the nHz region of the spectrum of primordial gravitational waves | In this paper we study the effect of cosmic neutrino decoupling on the
spectrum of cosmological gravitational waves (GWs). At temperatures T>>1 MeV,
neutrinos constitute a perfect fluid and do not hinder GW propagation, while
for T<<1 MeV they free-stream and have an effective viscosity that damps
cosmological GWs by a... | 1010.3849v2 |
2010-10-20 | Modified Landau levels, damped harmonic oscillator and two-dimensional pseudo-bosons | In a series of recent papers one of us has analyzed in some details a class
of elementary excitations called {\em pseudo-bosons}. They arise from a special
deformation of the canonical commutation relation $[a,a^\dagger]=\1$, which is
replaced by $[a,b]=\1$, with $b$ not necessarily equal to $a^\dagger$. Here,
after a ... | 1010.4221v1 |
2010-11-16 | Forcibly driven coherent soft phonons in GeTe with intense THz-rate pump fields | We propose an experimental technique to generate large amplitude coherent
phonons with irradiation of THz-rate pump pulses and to study the dynamics of
phase transition in GeTe ferroelectrics. When a single pump pulse irradiates
the sample at various pump power densities, the frequency of the soft phonon
decreases sub-... | 1011.3624v2 |
2010-11-21 | Regular and chaotic transport of discrete solitons in asymmetric potentials | Ratchet dynamics of topological solitons of the forced and damped discrete
double sine-Gordon system are studied. Directed transport occurring both in
regular and in chaotic regions of the phase space and its dependence on
damping, amplitude and frequency of the driving, asymmetry parameter, coupling
constant, has been... | 1011.4707v1 |
2010-11-26 | Dependence of entanglement on initial states under amplitude damping channel in non-inertial frames | Under amplitude damping channel, the dependence of the entanglement on the
initial states $|\Theta>_{1}$ and $|\Theta>_{2}$, which reduce to four
orthogonal Bell states if we take the parameter of states $\alpha=\pm
1/\sqrt{2}$ are investigated. We find that the entanglements for different
initial states will decay alo... | 1011.5700v3 |
2010-12-21 | Characterization of Decoherence from an Environmental Perspective | For the case of phase damping (pure decoherence) we investigate the extent to
which environmental traits are imprinted on an open quantum system. The
dynamics is described using the quantum channel approach. We study what the
knowledge of the channel may reveal about the nature of its underlying dynamics
and, conversel... | 1012.4685v1 |
2010-12-28 | Quantum Leptogenesis I | Thermal leptogenesis explains the observed matter-antimatter asymmetry of the
universe in terms of neutrino masses, consistent with neutrino oscillation
experiments. We present a full quantum mechanical calculation of the generated
lepton asymmetry based on Kadanoff-Baym equations. Origin of the asymmetry is
the depart... | 1012.5821v3 |
2011-01-06 | Chemical Enrichment in the Carbon-enhanced Damped Lyman $α$ System | We show that the recently observed elemental abundance pattern of the
carbon-rich metal-poor Damped Lyman $\alpha$ (DLA) system is in excellent
agreement with the nucleosynthesis yields of faint core-collapse supernovae of
primordial stars. The observed abundance pattern is not consistent with the
nucleosynthesis yield... | 1101.1227v2 |
2011-02-08 | Quantization of Damping Particle Based On New Variational Principles | In this paper a new approach is proposed to quantize mechanical systems whose
equations of motion can not be put into Hamiltonian form. This approach is
based on a new type of variational principle, which is adopted to a describe a
relation: a damping particle may shares a common phase curve with a free
particle, whose... | 1102.1573v2 |
2011-02-15 | Spin dynamics in the strong spin-orbit coupling regime | We study the spin dynamics in a high-mobility two dimensional electron gas
(2DEG) with generic spin-orbit interactions (SOIs). We derive a set of spin
dynamic equations which capture the purely exponential to the damped
oscillatory spin evolution modes observed in different regimes of SOI strength.
Hence we provide a f... | 1102.3170v1 |
2011-03-03 | Collective modes and the speed of sound in the Fulde-Ferrell-Larkin-Ovchinnikov state | We consider the density response of a spin-imbalanced ultracold Fermi gas in
an optical lattice in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We
calculate the collective mode spectrum of the system in the generalised random
phase approximation and find that though the collective modes are damped even
at zero te... | 1103.0696v2 |
2011-03-10 | Shocks in financial markets, price expectation, and damped harmonic oscillators | Using a modified damped harmonic oscillator model equivalent to a model of
market dynamics with price expectations, we analyze the reaction of financial
markets to shocks. In order to do this, we gather data from indices of a
variety of financial markets for the 1987 Black Monday, the Russian crisis of
1998, the crash ... | 1103.1992v2 |
2011-03-22 | Inductive determination of the optimum tunnel barrier thickness in magnetic tunnelling junction stacks for spin torque memory applications | We use pulsed inductive microwave magnetometry to study the precessional
magnetization dynamics of the free layer in CoFeB/MgO/CoFeB based magnetic
tunnelling junction stacks with varying MgO barrier thickness. From the field
dependence of the precession frequency we are able to derive the uniaxial
anisotropy energy an... | 1103.4248v1 |
2011-04-11 | Algebraic damping in the one-dimensional Vlasov equation | We investigate the asymptotic behavior of a perturbation around a spatially
non homogeneous stable stationary state of a one-dimensional Vlasov equation.
Under general hypotheses, after transient exponential Landau damping, a
perturbation evolving according to the linearized Vlasov equation decays
algebraically with th... | 1104.1890v2 |
2011-04-25 | Exactly Solvable Nonhomogeneous Burgers Equations with Variable Coefficients | We consider a nonhomogeneous Burgers equation with time variable
coefficients, and obtain an explicit solution of the general initial value
problem in terms of solution to a corresponding linear ODE. Special exact
solutions such as generalized shock and multi-shock solitary waves, triangular
wave, N-wave and rational t... | 1104.4717v1 |
2011-05-06 | System-environment dynamics of X-type states in noninertial frames | The system-environment dynamics of noninertial systems is investigated. It is
shown that for the amplitude damping channel: (i) the biggest difference
between the decoherence effect and the Unruh radiation on the dynamics of the
entanglement is the former only leads to entanglement transfer in the whole
system, but the... | 1105.1216v2 |
2011-05-10 | Spontaneous magnon decays in planar ferromagnet | We predict that spin-waves in an easy-plane ferromagnet have a finite
lifetime at zero temperature due to spontaneous decays. In zero field the
damping is determined by three-magnon decay processes, whereas decays in the
two-particle channel dominate in a transverse magnetic field. Explicit
calculations of the magnon d... | 1105.1893v1 |
2011-05-19 | Scaling of the higher-order flow harmonics: implications for initial-eccentricity models and the "viscous horizon" | The scaling properties of the flow harmonics for charged hadrons $v_{n}$ and
their ratios $[ v_n/(v_2)^{n/2}]_{n\geq 3}$, are studied for a broad range of
transverse momenta ($p_T$) and centrality selections in Au+Au and Pb+Pb
collisions at $\sqrt{s_{NN}}=0.2 \text{and} 2.76$ TeV respectively. At
relatively low $p_T$, ... | 1105.3782v2 |
2011-05-26 | Dynamics in the production of superheavy nuclei in low-energy heavy-ion collisions | We present a review of the recent progress of theoretical models on the
description of the formation of superheavy nuclei in collisions of heavy
systems. Two sorts of reactions that are the fusion-evaporation mechanism and
the massive damped collisions to produce superheavy nuclei are discussed.
Problems and further im... | 1105.5224v2 |
2011-06-01 | Effect of detuning on the phonon induced dephasing of optically driven InGaAs/GaAs quantum dots | Recently, longitudinal acoustic phonons have been identified as the main
source of the intensity damping observed in Rabi rotation measurements of the
ground-state exciton of a single InAs/GaAs quantum dot. Here we report
experiments of intensity damped Rabi rotations in the case of detuned laser
pulses, the results ha... | 1106.0142v1 |
2011-06-03 | Shear viscous effects on the primordial power spectrum from warm inflation | We compute the primordial curvature spectrum generated during warm inflation,
including shear viscous effects. The primordial spectrum is dominated by the
thermal fluctuations of the radiation bath, sourced by the dissipative term of
the inflaton field. The dissipative coefficient \Upsilon, computed from first
principl... | 1106.0701v1 |
2011-06-06 | Weakly nonlinear stochastic CGL equations | We consider the linear Schr\"odinger equation under periodic boundary
condition, driven by a random force and damped by a quasilinear damping: $$
\frac{d}{dt}u+i\big(-\Delta+V(x)\big) u=\nu \Big(\Delta u-\gr |u|^{2p}u-i\gi
|u|^{2q}u \Big) +\sqrt\nu\, \eta(t,x).\qquad (*) $$ The force $\eta$ is white
in time and smooth ... | 1106.1158v1 |
2011-06-09 | Investigating viscous damping using a webcam | We describe an experiment involving a mass oscillating in a viscous fluid and
analyze viscous damping of harmonic motion. The mechanical oscillator is
tracked using a simple webcam and an image processing algorithm records the
position of the geometrical center as a function of time. Interesting
information can be extr... | 1106.1823v1 |
2011-06-11 | Conformal and covariant formulation of the Z4 system with constraint-violation damping | We present a new formulation of the Einstein equations based on a conformal
and traceless decomposition of the covariant form of the Z4 system. This
formulation combines the advantages of a conformal decomposition, such as the
one used in the BSSNOK formulation (i.e. well-tested hyperbolic gauges, no need
for excision,... | 1106.2254v2 |
2011-06-14 | Oscillations of hot, young neutron stars: Gravitational wave frequencies and damping times | We study how the frequencies and damping times of oscillations of a newly
born, hot proto-neutron star depend on the physical quantities which
characterize the star quasi-stationary evolution which follows the bounce.
Stellar configurations are modeled using a microscopic equation of state
obtained within the Brueckner... | 1106.2736v1 |
2011-06-22 | Samll BGK waves and nonlinear Landau damping (higher dimensions) | Consider Vlasov-Poisson system with a fixed ion background and periodic
condition on the space variables, in any dimension d\geq2. First, we show that
for general homogeneous equilibrium and any periodic x-box, within any small
neighborhood in the Sobolev space W_{x,v}^{s,p} (p>1,s<1+(1/p)) of the steady
distribution f... | 1106.4368v1 |
2011-07-13 | q-damped Oscillator and degenerate roots of constant coefficients q-difference ODE | The classical model of q-damped oscillator is introduced and solved in terms
of Jackson q-exponential function for three different cases, under-damped,
over-damped and the critical one. It is shown that in all three cases solution
is oscillating in time but is unbounded and non-periodic. By q-periodic
function modulati... | 1107.2518v1 |
2011-07-13 | Increased Brownian force noise from molecular impacts in a constrained volume | We report on residual gas damping of the motion of a macroscopic test mass
enclosed in a nearby housing in the molecular flow regime. The damping
coefficient, and thus the associated thermal force noise, is found to increase
significantly when the distance between test mass and surrounding walls is
smaller than the tes... | 1107.2520v1 |
2011-07-13 | Dimension of attractors and invariant sets of damped wave equations in unbounded domains | Under fairly general assumptions, we prove that every compact invariant set
$\mathcal I$ of the semiflow generated by the semilinear damped wave equation
u_{tt}+\alpha u_t+\beta(x)u-\Deltau = f(x,u), (t,x)\in[0,+\infty[\times\Omega,
u = 0, (t,x)\in[0,+\infty[\times\partial\Omega in $H^1_0(\Omega)\times
L^2(\Omega) has ... | 1107.2589v1 |
2011-07-15 | K-shell photoionization of Nickel ions using R-matrix | We present R-matrix calculations of photoabsorption and photoionization cross
sections across the K edge of the Li-like to Ca-like ions stages of Ni.
Level-resolved, Breit-Pauli calculations were performed for the Li-like to
Na-like stages. Term-resolved calculations, which include the mass-velocity and
Darwin relativi... | 1107.3146v1 |
2011-07-20 | Bayesian Magnetohydrodynamic Seismology of Coronal Loops | We perform a Bayesian parameter inference in the context of resonantly damped
transverse coronal loop oscillations. The forward problem is solved in terms of
parametric results for kink waves in one-dimensional flux tubes in the thin
tube and thin boundary approximations. For the inverse problem, we adopt a
Bayesian ap... | 1107.3943v1 |
2011-07-31 | Evolution of cat states in a dissipative parametric amplifier: decoherence and entanglement | The evolution of the Schr\"{o}dinger-cat states in a dissipative parametric
amplifier is examined. The main tool in the analysis is the normally ordered
characteristic function. Squeezing, photon-number distribution and reduced
factorial moments are discussed for the single- and compound-mode cases. Also
the single-mod... | 1108.0127v1 |
2011-07-31 | Second-Order, Dissipative Tâtonnement: Economic Interpretation and 2-Point Limit Cycles | This paper proposes an alternative to the classical price-adjustment
mechanism (called "t\^{a}tonnement" after Walras) that is second-order in time.
The proposed mechanism, an analogue to the damped harmonic oscillator, provides
a dynamic equilibration process that depends only on local information. We show
how such a ... | 1108.0188v3 |
2011-08-02 | PHENIX Measurements of Higher-order Flow Harmonics in Au+Au collisions at Root_s = 200 GeV | Flow coefficients $v_n$ for $n$ = 2, 3, 4, characterizing the anisotropic
collective flow in Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV, are
presented. They indicate the expected growth of viscous damping for sound
propagation in the quark gluon plasma (QGP) produced in these collisions.
Hydrodynamical model compari... | 1108.0457v1 |
2011-08-10 | Critical exponents of steady-state phase transitions in fermionic lattice models | We discuss reservoir induced phase transitions of lattice fermions in the
non-equilibrium steady state (NESS) of an open system with local reservoirs.
These systems may become critical in the sense of a diverging correlation
length upon changing the reservoir coupling. We here show that the transition
to a critical sta... | 1108.2263v5 |
2011-09-09 | Observation of Spontaneous Brillouin Cooling | While radiation-pressure cooling is well known, the Brillouin scattering of
light from sound is considered an acousto-optical amplification-only process.
It was suggested that cooling could be possible in multi-resonance Brillouin
systems when phonons experience lower damping than light. However, this regime
was not ac... | 1109.2084v2 |
2011-09-14 | Oscillations of simple networks | To describe the flow of a miscible quantity on a network, we introduce the
graph wave equation where the standard continuous Laplacian is replaced by the
graph Laplacian. This is a natural description of an array of inductances and
capacities, of fluid flow in a network of ducts and of a system of masses and
springs. T... | 1109.3071v2 |
2011-09-21 | High-order explicit local time-stepping methods for damped wave equations | Locally refined meshes impose severe stability constraints on explicit
time-stepping methods for the numerical simulation of time dependent wave
phenomena. Local time-stepping methods overcome that bottleneck by using
smaller time-steps precisely where the smallest elements in the mesh are
located. Starting from classi... | 1109.4480v2 |
2011-09-21 | Anisotropic critical magnetic fluctuations in the ferromagnetic superconductor UCoGe | We report neutron scattering measurements of critical magnetic excitations in
the weakly ferromagnetic superconductor UCoGe. The strong non-Landau damping of
the excitations we observe, although unusual has been found in another related
ferromagnet, UGe2 at zero pressure. However, we also find there is a
significant an... | 1109.4541v1 |
2011-09-30 | PT-symmetry, indefinite damping and dissipation-induced instabilities | With perfectly balanced gain and loss, dynamical systems with indefinite
damping can obey the exact PT-symmetry being marginally stable with a pure
imaginary spectrum. At an exceptional point where the symmetry is spontaneously
broken, the stability is lost via passing through a non-semisimple 1:1
resonance. In the par... | 1110.0018v2 |
2011-10-01 | Electrical measurement of antivortex wall eigenfrequency | The dynamics of a ferromagnetic antivortex wall has been experimentally
studied in a magnetic nanostructure. Two different techniques have been used to
independently measure the eigenfrequency of an antivortex wall such as the
resonance excitation by sinusoidal microwave and the damped resonance
excitation induced by s... | 1110.0113v1 |
2011-10-06 | Comparative Wakefield Analysis of a First Prototype of a DDS Structure for CLIC Main Linac | A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an
alternative to the present baseline design which is based on heavy damping. A
first prototype, CLIC_DDS_A, for high power tests has been already designed and
is under construction. It is also foreseen to design a further prototype,
CLIC_DDS_B,... | 1110.1207v1 |
2011-10-12 | Nonlinear dynamic analysis of an optimal particle damper | We study the dynamical behavior of a single degree of freedom mechanical
system with a particle damper. The particle (granular) damping was optimized
for the primary system operating condition by using an appropriate gap size for
a prismatic enclosure. The particles absorb the kinetic energy of the vibrating
structure ... | 1110.2800v1 |
2011-10-14 | Effect of Compton Scattering on the Electron Beam Dynamics at the ATF Damping Ring | Compton scattering provides one of the most promising scheme to obtain
polarized positrons for the next generation of $e^-$ -- $e^+$ colliders.
Moreover it is an attractive method to produce monochromatic high energy
polarized gammas for nuclear applications and X-rays for compact light sources.
In this framework a fou... | 1110.3241v1 |
2011-10-28 | Stability of linear and non-linear lambda and tripod systems in the presence of amplitude damping | We present the stability analysis of the dark states in the adiabatic passage
for the linear and non-linear lambda and tripod systems in the presence of
amplitude damping (losses). We perform an analytic evaluation of the real parts
of eigenvalues of the corresponding Jacobians, the non-zero eigenvalues of
which are fo... | 1110.6379v2 |
2011-11-07 | Control of Material Damping in High-Q Membrane Microresonators | We study the mechanical quality factors of bilayer aluminum/silicon-nitride
membranes. By coating ultrahigh-Q Si3N4 membranes with a more lossy metal, we
can precisely measure the effect of material loss on Q's of tensioned resonator
modes over a large range of frequencies. We develop a theoretical model that
interpret... | 1111.1703v2 |
2011-11-15 | Thermodynamic anomaly of the free damped quantum particle: the bath perspective | A possible definition of the specific heat of open quantum systems is based
on the reduced partition function of the system. For a free damped quantum
particle, it has been found that under certain conditions, this specific heat
can become negative at low temperatures. In contrast to the conventional
approaches focusin... | 1111.3594v2 |
2011-12-02 | On the propagation of binary signals in damped mechanical systems of oscillators | In the present work, we explore efficient ways to transmit binary information
in discrete, semi-infinite chains of coupled oscillators using the process of
nonlinear supratransmission. A previous work showed that such transmission is
possible and, indeed, reliable under the idealistic condition when weak or no
damping ... | 1112.0585v1 |
2011-12-02 | On the simulation of the energy transmission in the forbidden band-gap of a spatially discrete double sine-Gordon system | In this work, we present a numerical method to consistently approximate
solutions of a spatially discrete, double sine-Gordon chain which considers the
presence of external damping. In addition to the finite-difference scheme
employed to approximate the solution of the difference-differential equations
of the model und... | 1112.0595v1 |
2011-12-11 | Spin-polarized current effect on antiferromagnet magnetization in a ferromagnet - antiferromagnet nanojunction: Theory and simulation | Spin-polarized current effect is studied on the static and dynamic
magnetization of the antiferromagnet in a ferromagnet - antiferromagnet
nanojunction. The macrospin approximation is generalized to antiferromagnets.
Canted antiferromagnetic configuration and resulting magnetic moment are
induced by an external magneti... | 1112.2362v1 |
2011-12-15 | Analytic gas orbits in an arbitrary rotating galactic potential using the linear epicyclic approximation | A code, Epic5, has been developed which computes, in the two-dimensional
case, the initially circular orbits of guiding centra in an arbitrary
axisymmetric potential with an arbitrary, weak perturbing potential in solid
body rotation. This perturbing potential is given by its Fourier expansion. The
analytic solution so... | 1112.3658v1 |
2011-12-21 | A numerical method for computing radially symmetric solutions of a dissipative nonlinear modified Klein-Gordon equation | In this paper we develop a finite-difference scheme to approximate radially
symmetric solutions of the initial-value problem with smooth initial conditions
in an open sphere around the origin, where the internal and external damping
coefficients are constant, and the nonlinear term follows a power law. We prove
that ou... | 1112.4921v1 |
2011-12-23 | Temperature gradient assisted magnetodynamics in a ferromagnetic nanowire | The dynamics of the low energy excitations in a ferromagnet is studied in
case a temperature gradient is coupled to the local magnetization. Due to the
different time scales of changing temperature and magnetization it is argued
that only the coupling between the spatially varying part of the temperature
field and the ... | 1112.5562v1 |
2012-01-04 | A new candidate for probing Population III nucleosynthesis with carbon-enhanced damped Lyman-alpha systems | We report the identification of a very metal-poor damped Lyman-alpha system
(DLA) at z_abs = 3.067295 that is modestly carbon-enhanced, with an iron
abundance of ~1/700 solar ([Fe/H] = -2.84) and [C,O/Fe] ~ +0.6. Such an
abundance pattern is likely to be the result of nucleosynthesis by massive
stars. On the basis of 1... | 1201.1004v2 |
2012-01-06 | Magnetic field decay with Hall drift in neutron star crusts | The dynamics of magnetic field decay with Hall drift is investigated.
Assuming that axisymmetric magnetic fields are located in a spherical crust
with uniform conductivity and electron number density, long-term evolution is
calculated up to Ohmic dissipation. The nonlinear coupling between poloidal and
toroidal compone... | 1201.1346v1 |
2012-01-06 | Reversible Dissipative Processes, Conformal Motions and Landau Damping | The existence of a dissipative flux vector is known to be compatible with
reversible processes, provided a timelike conformal Killing vector (CKV)
$\chi^\alpha=\frac{V^\alpha}{T}$ (where $V^\alpha$ and $T$ denote the
four-velocity and temperature respectively) is admitted by the space-time. Here
we show that if a const... | 1201.1390v1 |
2012-01-19 | Wave Leakage and Resonant Absorption in a Loop Embedded in a Coronal Arcade | We investigate the temporal evolution of impulsively generated perturbations
in a potential coronal arcade with an embedded loop. As the initial
configuration we consider a coronal loop, represented by a density enhancement,
which is unbounded in the ignorable direction of the arcade. The linearized
time-dependent magn... | 1201.4042v1 |
2012-02-07 | The Fine Structure Constant and the CMB Damping Scale | The recent measurements of the Cosmic Microwave Background anisotropies at
arcminute angular scales performed by the ACT and SPT experiments are probing
the damping regime of CMB fluctuations. The analysis of these datasets
unexpectedly suggests that the effective number of relativistic degrees of
freedom is larger tha... | 1202.1476v1 |
2012-02-08 | Evidence of Wave Damping at Low Heights in a Polar Coronal Hole | We have measured the widths of spectral lines from a polar coronal hole using
the Extreme Ultraviolet Imaging Spectrometer onboard Hinode. Polar coronal
holes are regions of open magnetic field and the source of the fast solar wind.
We find that the line widths decrease at relatively low heights. Previous
observations ... | 1202.1743v2 |
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