publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2003-08-19 | Magnetization relaxation in (Ga,Mn)As ferromagnetic semiconductors | We describe a theory of Mn local-moment magnetization relaxation due to p-d
kinetic-exchange coupling with the itinerant-spin subsystem in the
ferromagnetic semiconductor (Ga,Mn)As alloy. The theoretical Gilbert damping
coefficient implied by this mechanism is calculated as a function of Mn moment
density, hole concent... | 0308386v3 |
2003-09-18 | Memory-function approach to the normal-state optical properties of the Bechgaard salt (TMTSF)_2PF_6 | The gauge invariant, two-component optical conductivity model, with a
correlation gap structure related to the umklapp scattering processes, is
applied to the quasi-one-dimensional electronic systems and compared to the
recent measurements on the Bechgaard salt (TMTSF)_2PF_6. The optical response
of both the insulating... | 0309419v1 |
2003-10-03 | Effects of electrostatic fields and Casimir force on cantilever vibrations | The effect of an external bias voltage and fluctuating electromagnetic fields
on both the fundamental frequency and damping of cantilever vibrations is
considered. An external voltage induces surface charges causing
cantilever-sample electrostatic attraction. A similar effect arises from
charged defects in dielectrics ... | 0310081v1 |
2003-10-07 | Precessional switching of thin nanomagnets: analytical study | We study analytically the precessional switching of the magnetization of a
thin macrospin. We analyze its response when subjected to an external field
along its in-plane hard axis. We derive the exact trajectories of the
magnetization. The switching versus non switching behavior is delimited by a
bifurcation trajectory... | 0310147v1 |
2003-11-27 | Temperature dependent Bogoliubov approximation in the classical fields approach to weakly interacting Bose gas | A classical fields approximation to the finite temperature microcanonical
thermodynamics of weakly interacting Bose gas is applied to the idealized case
of atoms confined in a box with periodic boundary conditions. We analyze in
some detail the microcanonical temperature in the model. We also analyze the
spectral prope... | 0311622v1 |
2003-12-29 | Plasmon attenuation and optical conductivity of a two-dimensional electron gas | In a ballistic two-dimensional electron gas, the Landau damping does not lead
to plasmon attenuation in a broad interval of wave vectors q << k_F. Similarly,
it does not contribute to the optical conductivity \sigma (\omega, q) in a wide
domain of its arguments, E_F > \omega > qv_F, where E_F, k_F and v_F are,
respecti... | 0312684v3 |
2004-02-03 | First-principles study of magnetization relaxation enhancement and spin-transfer in thin magnetic films | The interface-induced magnetization damping of thin ferromagnetic films in
contact with normal-metal layers is calculated from first principles for clean
and disordered Fe/Au and Co/Cu interfaces. Interference effects arising from
coherent scattering turn out to be very small, consistent with a very small
magnetic cohe... | 0402088v2 |
2004-03-05 | Mode-coupling theory and molecular dynamics simulation for heat conduction in a chain with transverse motions | We study heat conduction in a one-dimensional chain of particles with
longitudinal as well as transverse motions. The particles are connected by
two-dimensional harmonic springs together with bending angle interactions. The
problem is analyzed by mode-coupling theory and compared with molecular
dynamics. We find very g... | 0403162v1 |
2004-03-21 | Evidence for Superfluidity in a Resonantly Interacting Fermi Gas | We observe collective oscillations of a trapped, degenerate Fermi gas of
$^6$Li atoms at a magnetic field just above a Feshbach resonance, where the
two-body physics does not support a bound state. The gas exhibits a radial
breathing mode at a frequency of 2837(05) Hz, in excellent agreement with the
frequency of $\nu_... | 0403540v2 |
2004-03-22 | Parametric Driving of Dark Solitons in Atomic Bose-Einstein Condensates | A dark soliton oscillating in an elongated harmonically-confined atomic
Bose-Einstein condensate continuously exchanges energy with the sound field.
Periodic optical `paddles' are employed to controllably enhance the sound
density and transfer energy to the soliton, analogous to parametric driving. In
the absence of da... | 0403566v2 |
2004-04-09 | Network-Induced Oscillatory Behavior in Material Flow Networks | Network theory is rapidly changing our understanding of complex systems, but
the relevance of topological features for the dynamic behavior of metabolic
networks, food webs, production systems, information networks, or cascade
failures of power grids remains to be explored. Based on a simple model of
supply networks, w... | 0404226v1 |
2004-04-28 | Dynamics of the Electro-Reflective Response of TaS3 | We have observed a large (~1%) change in infrared reflectance of the
charge-density-wave (CDW) conductor, orthorhombic TaS3, when its CDW is
depinned. The change is concentrated near one current contact. Assuming that
the change in reflectance is proportional to the degree of CDW polarization, we
have studied the dynam... | 0404690v1 |
2004-05-06 | Damping of the de Haas-van Alphen oscillations in the superconducting state of MgB_2 | The de Haas-van Alphen (dHvA) signal arising from orbits on the $\pi$ Fermi
surface sheet of the two-gap superconductor MgB$_2$ has been observed in the
vortex state below $H_{c2}$. An extra attenuation of the dHvA signal, beyond
those effects described in the conventional Lifshitz-Kosevich expression, is
seen due to t... | 0405120v1 |
2004-05-26 | Magnetic droplets in a metal close to a ferromagnetic quantum critical point | Using analytical and path integral Monte Carlo methods, we study the
susceptibility $\chi_{dc}(T)$ of a spin-S impurity with XY rotational symmetry
embedded in a metal. Close to a ferromagnetic quantum critical point, the
impurity polarizes conduction electrons in its vicinity and forms a large
magnetic droplet with mo... | 0405618v2 |
2004-06-29 | Pairing gaps in atomic gases at the BCS-BEC crossover | Strong evidence for pairing and superfluidity has recently been found in
atomic Fermi gases at the BCS-BEC crossover both in collective modes and RF
excitation energies. It is argued that the scale for the effective pairing gaps
measured in RF experiments is set by the lowest quasiparticle in-gap excitation
energies. T... | 0406714v3 |
2004-08-26 | Decoherence of Rabi oscillations in a single quantum dot | We develop a realistic model of Rabi oscillations in a quantum-dot
photodiode. Based in a multi-exciton density matrix formulation we show that
for short pulses the two-level models fails and higher levels should be taken
into account. This affects some of the experimental conclusions, such as the
inferred efficiency o... | 0408570v2 |
2004-08-28 | Breakdown of Hydrodynamics in the Radial Breathing Mode of a Strongly-Interacting Fermi Gas | We measure the magnetic field dependence of the frequency and damping time
for the radial breathing mode of an optically trapped, Fermi gas of $^6$Li
atoms near a Feshbach resonance. The measurements address the apparent
discrepancy between the results of Kinast et al., [Phys. Rev. Lett. {\bf 92},
150402 (2004)] and th... | 0408634v2 |
2004-10-01 | Magnetic Properties of Cuprate Perovskites | The magnetic susceptibility of underdoped yttrium and lanthanum cuprates is
interpreted based on the self-consistent solution of the t-J model of a Cu-O
plane. The calculations reproduce correctly the frequency dependencies of the
susceptibility in YBa2Cu3O_{7-y} and La_{2-x}Sr_xCuO4 attributing their
dissimilarity to ... | 0410009v1 |
2004-11-12 | Microwave induced resistance oscillations on a high-mobility 2DEG: absorption/reflection and temperature damping experiments | In this work we address experimentally a number of unresolved issues related
to microwave induced resistance oscillations (MIRO) and the zero-resistance
states observed recently on very high-mobility 2D electron gases in GaAs/AlGaAs
heterostructures. In particular, we examine electrodynamic effects via
reflection/absor... | 0411338v1 |
2004-11-17 | Path integral derivation of Bloch-Redfield equations for a qubit weakly coupled to a heat bath: Application to nonadiabatic transitions | Quantum information processing has greatly increased interest in the
phenomenon of environmentally-induced decoherence. The spin boson model is
widely used to study the interaction between a spin-modelling a quantum
particle moving in a double well potential-and its environment-modelled by a
heat bath of harmonic oscil... | 0411443v1 |
2004-11-24 | Josephson tunnel junctions with nonlinear damping for RSFQ-qubit circuit applications | We demonstrate that shunting of Superconductor-Insulator-Superconductor
Josephson junctions by Superconductor-Insulator-Normal metal (S-I-N) structures
having pronounced non-linear I-V characteristics can remarkably modify the
Josephson dynamics. In the regime of Josephson generation the phase behaves as
an overdamped ... | 0411607v1 |
2004-12-01 | Reply to Millis et al. on "A Tale of Two Theories: Quantum Griffiths Effects in Metallic Systems" | In a recent paper (cond-mat/0411197) we showed the equivalence of two
seemingly contradictory theories on Griffiths-McCoy singularities (GMS) in
metallic antiferromagnets close to a quantum critical point (QCP). In a recent
comment, Millis {\it et al.} (cond-mat/0411738) argue that in heavy-fermion
materials the electr... | 0412020v2 |
2005-01-04 | On continuum modeling of sputter erosion under normal incidence: interplay between nonlocality and nonlinearity | Under specific experimental circumstances, sputter erosion on semiconductor
materials exhibits highly ordered hexagonal dot-like nanostructures. In a
recent attempt to theoretically understand this pattern forming process, Facsko
et al. [Phys. Rev. B 69, 153412 (2004)] suggested a nonlocal, damped
Kuramoto-Sivashinsky ... | 0501049v2 |
2005-01-18 | Incommensurate spin dynamics in underdoped cuprate perovskites | The incommensurate magnetic response observed in normal-state cuprate
perovskites is interpreted based on the projection operator formalism and the
t-J model of Cu-O planes. In agreement with experiment the calculated
dispersion of maxima in the susceptibility has the shape of two parabolas with
upward and downward bra... | 0501418v1 |
2005-02-21 | Velocity dependence of atomic-scale friction: a comparative study of the one- and two-dimensional Tomlinson model | We present a comparative analysis of the velocity dependence of atomic-scale
friction for the Tomlinson model, at zero and finite temperatures, in 1D and
2D, and for different values of the damping. Combining analytical arguments
with numerical simulations, we show that an appreciable velocity dependence of
the kinetic... | 0502496v1 |
2005-02-28 | Magnetization dynamics of two interacting spins in an external magnetic field | The longitudinal relaxation time of the magnetization of a system of two
exchange coupled spins subjected to a strong magnetic field is calculated
exactly by averaging the stochastic Gilbert-Landau-Lifshitz equation for the
magnetization, i.e., the Langevin equation of the process, over its
realizations so reducing the... | 0502661v2 |
2005-03-12 | Collective Oscillations of Strongly Correlated One-Dimensional Bosons on a Lattice | We study the dipole oscillations of strongly correlated 1D bosons, in the
hard-core limit, on a lattice, by an exact numerical approach. We show that far
from the regime where a Mott insulator appears in the system, damping is always
present and increases for larger initial displacements of the trap, causing
dramatic c... | 0503302v2 |
2005-04-28 | Coherence properties of bulk matter | We prove a theorem, using the density functional approach and relying on a
classical result by Lieb and Simon on Thomas-Fermi model, showing that in the
thermodynamic limit bulk matter is at most semiclassical and coherence
preserving. The connection between quantum fluid dynamics and density
functional theory in the f... | 0504768v3 |
2005-05-19 | Harmonic Content of Strain-induced Potential Modulation in Unidirectional Lateral Superlattices | Detailed analysis of the commensurability oscillation (CO) has been performed
on unidirectional lateral superlattices with periods ranging from a=92 to 184
nm. Fourier analysis reveals the second (and the third) harmonics along with
the fundamental oscillation for a>=138 nm (184 nm) at low-enough temperature,
evincing ... | 0505479v1 |
2005-06-14 | Lifetime of the first and second collective excitations in metallic nanoparticles | We determine the lifetime of the surface plasmon in metallic nanoparticles
under various conditions, concentrating on the Landau damping, which is the
dominant mechanism for intermediate-size particles. Besides the main
contribution to the lifetime, which smoothly increases with the size of the
particle, our semiclassi... | 0506320v2 |
2005-07-27 | Dynamics of a nanomechanical resonator coupled to a superconducting single-electron transistor | We present an analysis of the dynamics of a nanomechanical resonator coupled
to a superconducting single electron transistor (SSET) in the vicinity of the
Josephson quasiparticle (JQP) and double Josephson quasiparticle (DJQP)
resonances. For weak coupling and wide separation of dynamical timescales, we
find that for e... | 0507645v1 |
2005-08-01 | Unexpected Effect of Internal Degrees of Freedom on Transverse Phonons in Supercooled Liquids | We show experimentally that in a supercooled liquid composed of molecules
with internal degrees of freedom the internal modes contribute to the frequency
dependent shear viscosity and damping of transverse phonons, which results in
an additional broadening of the transverse Brillouin lines. Earlier, only the
effect of ... | 0508046v1 |
2005-08-05 | Damping of vortex waves in a superfluid | The damping of vortex cyclotron modes is investigated within a generalized
quantum theory of vortex waves. Similarly to the case of Kelvin modes, the
friction coefficient turns out to be essentially unchanged under such
oscillations, but it is shown to be affected by appreciable memory corrections.
On the other hand, t... | 0508167v1 |
2005-08-08 | Collective excitations of low density fermion-boson quantum-liquid mixtures | We investigate the collective excitations of a low temperature dilute gas
mixture that consists of a Bose-Einstein condensate and a Fermi-gas that is a
normal (i.e. non-superfluid) Fermi-liquid. We find that the BEC-mediated
fermion-fermion interactions, as a consequence of retardation, can become
repulsive and support... | 0508207v1 |
2005-09-02 | Inhomogeneous soliton ratchets under two ac forces | We extend our previous work on soliton ratchet devices [L. Morales-Molina et
al., Eur. Phys. J. B 37, 79 (2004)] to consider the joint effect of two ac
forces including non-harmonic drivings, as proposed for particle ratchets by
Savele'v et al. [Europhys. Lett. 67}, 179 (2004); Phys. Rev. E {\bf 70} 066109
(2004)]. Cur... | 0509051v1 |
2005-10-27 | Acoustic damping in Li$_2$O-2B$_2$O$_3$ glass observed by inelastic x-ray and optical Brillouin scattering | The dynamic structure factor of lithium-diborate glass has been measured at
several values of the momentum transfer $Q$ using high resolution inelastic
x-ray scattering. Much attention has been devoted to the low $Q$-range, below
the observed Ioffe-Regel crossover \qco{}$\simeq$ 2.1 nm$^{-1}$. We find that
below \qco{}... | 0510714v1 |
2005-12-07 | Acoustic attenuation probe for fermion superfluidity in ultracold atom gases | Dilute gas Bose-Einstein condensates (BEC's), currently used to cool
fermionic atoms in atom traps, can also probe the superfluidity of these
fermions. The damping rate of BEC-acoustic excitations (phonon modes), measured
in the middle of the trap as a function of the phonon momentum, yields an
unambiguous signature of... | 0512134v4 |
2005-12-29 | Current-induced magnetization dynamics in disordered itinerant ferromagnets | Current-driven magnetization dynamics in ferromagnetic metals are studied in
a self-consistent adiabatic local-density approximation in the presence of
spin-conserving and spin-dephasing impurity scattering. Based on a quantum
kinetic equation, we derive Gilbert damping and spin-transfer torques entering
the Landau-Lif... | 0512715v4 |
2006-01-11 | Apparent phonon side band modes in pi-conjugated systems: polymers, oligomers and crystals | The emission spectra of many pi-conjugated polymers and oligomers contain
side-band replicas with apparent frequencies that do not match the Raman active
mode frequencies. Using a time dependent model we show that in such many mode
systems, the increased damping of the time dependent transition dipole moment
correlatio... | 0601218v1 |
2006-03-01 | Renormalization of the electron-spin-fluctuation interaction in the t-t'-U Hubbard model | We study the renormalization of the electron-spin-fluctuation (el-sp) vertex
in a two-dimensional Hubbard model with nearest-neighbor (t) and
next-nearest-neighbor (t') hopping by a Quantum-Monte-Carlo calculation. Our
results show that for t'=0, the renormalized el-sp vertex decreases quite
generally with decreasing t... | 0603014v3 |
2006-07-18 | Equilibrium and non-equilibrium dynamics of the sub-ohmic spin-boson model | Employing the non-perturbative numerical renormalization group method, we
study the dynamics of the spin-boson model, which describes a two-level system
coupled to a bosonic bath with spectral density J(omega) propto omega^s. We
show that, in contrast to the case of ohmic damping, the delocalized phase of
the sub-ohmic... | 0607443v2 |
2006-09-29 | Quantum master equation for electron transport through quantum dots and single molecules | A quantum master equation (QME) is derived for the many-body density matrix
of an open current-carrying system weakly coupled to two metal leads. The
dynamics and the steady-state properties of the system for arbitrary bias are
studied using projection operator techniques, which keep track of number of
electrons in the... | 0610004v1 |
2006-10-25 | Pulse and hold strategy for switching current measurements | We investigate by theory and experiment, the Josephson junction switching
current detector in an environment with frequency dependent damping. Analysis
of the circuit's phase space show that a favorable topology for switching can
be obtained with overdamped dynamics at high frequencies. A pulse-and-hold
method is descr... | 0610704v2 |
2006-10-29 | Experimental Studies of Low-field Landau Quantization in Two-dimensional Electron Systems in GaAs/AlGaAs Heterostructures | By applying a magnetic field perpendicular to GaAs/AlGaAs two-dimensional
electron systems, we study the low-field Landau quantization when the thermal
damping is reduced with decreasing the temperature. Magneto-oscillations
following Shubnikov-de Haas (SdH) formula are observed even when their
amplitudes are so large ... | 0610805v1 |
2007-01-12 | Electron spin quantum beats in positively charged quantum dots: nuclear field effects | We have studied the electron spin coherence in an ensemble of positively
charged InAs/GaAs quantum dots. In a transverse magnetic field, we show that
two main contributions must be taken into account to explain the damping of the
circular polarization oscillations. The first one is due to the nuclear field
fluctuations... | 0701284v2 |
2007-02-05 | Verification of stable operation of rapid single flux quantum devices with selective dissipation | It has been suggested that Rapid Single Flux Quantum (RSFQ) devices could be
used as the classical interface of superconducting qubit systems. One problem
is that the interface acts as a dissipative environment for a qubit. Recently
ways to modify the RSFQ damping to reduce the dissipation have been introduced.
One of ... | 0702104v1 |
2007-02-21 | RPAE versus RPA for the Tomonaga model with quadratic energy dispersion | Recently the damping of the collective charge (and spin) modes of interacting
fermions in one spatial dimension was studied. It results from the nonlinear
correction to the energy dispersion in the vicinity of the Fermi points. To
investigate the damping one has to replace the random phase approximation (RPA)
bare bubb... | 0702488v2 |
2007-03-01 | Spin dynamics across the superfluid-insulator transition of spinful bosons | Bosons with non-zero spin exhibit a rich variety of superfluid and insulating
phases. Most phases support coherent spin oscillations, which have been the
focus of numerous recent experiments. These spin oscillations are Rabi
oscillations between discrete levels deep in the insulator, while deep in the
superfluid they c... | 0703011v2 |
2007-03-21 | Edge magnetoplasmons in a partially screened two-dimensional electron gas on a helium surface | We report a study of edge magnetoplasmons in a partially-screened system of
electrons on a helium surface. We compare experimental results with theories of
the frequency, damping, and penetration-depth dependence on magnetic field,
temperature-dependent damping, and the dependence of the frequency on
screening. We show... | 0703558v1 |
1997-02-12 | On the problem of semiinfinite beam oscillation with internal damping | We study the Cauchy problem for the equation of the form $$ \ddot{u}(t) +
(\aa A + B)\dot{u}(t) + (A+G)u(t) = 0,\tag* $$ where $A$, $B$, and $G$ are \o s
in a Hilbert space $\Cal H$ with $A$ selfadjoint, $\sigma(A)=[0,\infty)$,
$B\ge0$ bounded, and $G$ symmetric and $A$-subordinate in a certain sense.
Spectral properti... | 9702007v1 |
1994-04-14 | Decoherence, Correlation, and Unstable Quantum States in Semiclassical Cosmology | It is demonstrated that almost any S-matrix of quantum field theory in curved
spaces posses an infinite set of complex poles (or branch cuts). These poles
can be transformed into complex eigenvalues, the corresponding eigenvectors
being Gamow vectors. All this formalism, which is heuristic in ordinary Hilbert
space, be... | 9404028v1 |
1994-09-27 | Effects of weak self-interactions in a relativistic plasma on cosmological perturbations | The exact solutions for linear cosmological perturbations which have been
obtained for collisionless relativistic matter within thermal field theory are
extended to a self-interacting case. The two-loop contributions of scalar
$\lambda\phi^4$ theory to the thermal graviton self-energy are evaluated, which
give the $O(\... | 9409055v2 |
1995-03-07 | ON THE OSCILLATION SPECTRA OF ULTRA COMPACT STARS | Quasinormal modes of ultra compact stars with uniform energy density have
been calculated. For less compact stars, there is only one very slowly damped
polar mode (corresponding to the Kelvin f-mode) for each spherical harmonic
index $l$. Further long-lived modes become possible for a sufficiently compact
star (roughly... | 9503012v1 |
1998-02-13 | Radiation Damping in FRW Space-times with Different Topologies | We study the role played by the compactness and the degree of connectedness
in the time evolution of the energy of a radiating system in the
Friedmann-Robertson-Walker (FRW) space-times whose $t=const $ spacelike
sections are the Euclidean 3-manifold ${\cal R}^3$ and six topologically
non-equivalent flat orientable com... | 9802031v1 |
1998-05-06 | Damping of Gravitational Waves and Density Perturbations in the Early Universe | Since the discovery of the large angular scale anisotropies in the microwave
background radiation, the behaviour of cosmological perturbations (especially,
density perturbations and gravitational waves) has been of great interest. In
this study, after a detailed and rigorous treatment of the behaviour of
gravitational ... | 9805016v1 |
1998-11-11 | Late-Time Evolution of Realistic Rotating Collapse and The No-Hair Theorem | We study analytically the asymptotic late-time evolution of realistic
rotating collapse. This is done by considering the asymptotic late-time
solutions of Teukolsky's master equation, which governs the evolution of
gravitational, electromagnetic, neutrino and scalar perturbations fields on
Kerr spacetimes. In accordanc... | 9811032v2 |
1999-09-22 | Vorticity affects the stability of neutron stars | The spin rate \Omega of neutron stars at a given temperature T is constrained
by the interplay between gravitational-radiation instabilities and viscous
damping. Navier-Stokes theory has been used to calculate the viscous damping
timescales and produce a stability curve for r-modes in the (\Omega,T) plane.
In Navier-St... | 9909073v2 |
2000-02-02 | Active controls in interferometric detectors of gravitational waves: inertial damping of the VIRGO superattenuator | The operation of an interferometer for gravitational waves detection requires
sophisticated feedback controls in many parts of the apparatus. The aim of this
lecture is to introduce the types of problems to be faced in this line of
research. The attention is focused on the "inertial damping" of the test mass
suspension... | 0002006v2 |
2000-08-09 | Gravitational Wave Damping of Neutron Star Wobble | We calculate the effect of gravitational wave (gw) back-reaction on realistic
neutron stars (NS's) undergoing torque-free precession. By `realistic' we mean
that the NS is treated as a mostly-fluid body with an elastic crust, as opposed
to a rigid body. We find that gw's damp NS wobble on a timescale tau_{theta}
approx... | 0008021v1 |
2000-11-30 | Tests of strong-field gravity and gravitational radiation damping in binary-pulsar systems | This talk reviews the constraints imposed by binary-pulsar data on gravity
theories, and notably on "scalar-tensor" theories which are the most natural
alternatives to general relativity. Because neutron stars have a strong
gravitational binding energy, binary-pulsar tests are qualitatively different
from solar-system ... | 0011114v1 |
2001-07-17 | Properties of r modes in rotating magnetic neutron stars. I. Kinematic Secular Effects and Magnetic Evolution Equations | The instability of r-mode oscillations in rapidly rotating neutron stars has
attracted attention as a potential mechanism for producing high frequency,
almost periodic gravitational waves. The analyses carried so far have shown the
existence of these modes and have considered damping by shear and bulk
viscosity. Howeve... | 0107061v1 |
2006-12-07 | Improved calculation of relic gravitational waves | In this paper, we improve the calculation of the relic gravitational waves
(RGW) in two aspects: First, we investigate the transfer function after
considering the redshift-suppression effect, the accelerating expansion effect,
the damping effect of free-streaming relativistic particles, and the damping
effect of cosmic... | 0612041v3 |
2007-01-16 | Influence of Lorentz violation on Dirac quasinormal modes in the Schwarzschild black hole spacetime | Using the third-order WKB approximation and monodromy methods, we investigate
the influence of Lorentz violating coefficient $b$ (associated with a special
axial-vector $b_{\mu}$ field) on Dirac quasinormal modes in the Schwarzschild
black hole spacetime. At fundamental overtone, the real part decreases linearly
as the... | 0701089v1 |
2007-03-29 | Constraint Damping in First-Order Evolution Systems for Numerical Relativity | A new constraint suppressing formulation of the Einstein evolution equations
is presented, generalizing the five-parameter first-order system due to Kidder,
Scheel and Teukolsky (KST). The auxiliary fields, introduced to make the KST
system first-order, are given modified evolution equations designed to drive
constrain... | 0703145v1 |
1994-01-21 | Transport Properties of Quark and Gluon Plasmas | The kinetic properties of relativistic quark-gluon and electron-photon
plasmas are described in the weak coupling limit. The troublesome Rutherford
divergence at small scattering angles is screened by Debye screening for the
longitudinal or electric part of the interactions. The transverse or magnetic
part of the inter... | 9401300v1 |
1994-04-20 | Electroweak Baryogenesis and Standard Model CP Violation | We analyze the mechanism of electroweak baryogenesis proposed by Farrar and
Shaposhnikov in which the phase of the CKM mixing matrix is the only source of
$CP$ violation. This mechanism is based on a phase separation of baryons via
the scattering of quasiparticles by the wall of an expanding bubble produced at
the elec... | 9404302v1 |
1994-06-11 | Standard Model CP-violation and Baryon asymmetry Part II: Finite Temperature | We consider the scattering of quasi-particles off the boundary created during
a first order electroweak phase transition. Spatial coherence is lost due to
the quasi-quark damping rate, and we show that reflection on the boundary is
suppressed, even at tree-level. Simply on CP considerations, we argue against
electrowea... | 9406289v2 |
1995-12-12 | Bubble Collisions and Defect Formation in a Damping Environment | Within the context of a first-order phase transition in the early Universe,
we study the collision process for vacuum bubbles expanding in a plasma. The
effects of the plasma are simulated by introducing a damping term in the
equations of motion for a $U(1)$ global field. We find that Lorentz-contracted
spherically sym... | 9512290v1 |
1996-09-02 | The quasiparticle structure of hot gauge theories | The study of the ultrarelativistic plasmas in perturbation theory is plagued
with infrared divergences which are not eliminated by the screening
corrections. They affect, in particular, the computation of the lifetime of the
elementary excitations, thus casting doubt on the validity of the quasiparticle
picture. We sho... | 9609225v1 |
1996-10-18 | Finiteness of Hot Classical Scalar Field Theory and the Plasmon Damping Rate | We investigate the renormalizability of the classical $\phi^4$ theory at
finite temperature. We calculate the time-dependent two point function to two
loop order and show that it can be rendered finite by the counterterms of the
classical static theory. As an application the classical plasmon damping rate
is found to b... | 9610415v2 |
1996-12-30 | Defect Formation in First Order Phase Transitions with Damping | Within the context of first order phase transitions in the early universe, we
study the influence of a coupling between the (global U(1)) scalar driving the
transition and the rest of the matter content of the theory. The effect of the
coupling on the scalar is simulated by introducing a damping term in its
equations o... | 9612487v1 |
1997-07-28 | Plasmon properties in classical lattice gauge theory | In order to investigate the features of the classical approximation at high
temperatures for real time correlation functions, the plasmon frequencies and
damping rates were recently computed numerically in the SU(2)+Higgs model and
in the pure SU(2) theory. We compare the lattice results with leading order
hard thermal... | 9707489v2 |
1998-09-11 | Dynamical renormalization group resummation of finite temperature infrared divergences | We introduce the method of dynamical renormalization group to study
relaxation and damping out of equilibrium directly in real time and applied it
to the study of infrared divergences in scalar QED. This method allows a
consistent resummation of infrared effects associated with the exchange of
quasistatic transverse ph... | 9809346v2 |
1999-02-12 | Beyond HTL: The Classical Kinetic Theory of Landau Damping for Selfinteracting Scalar Fields in the Broken Phase | The effective theory of low frequency fluctuations of selfinteracting scalar
fields is constructed in the broken symmetry phase. The theory resulting from
integrating fluctuations with frequencies much above the spontanously generated
mass scale $(p_0>>M)$ is found to be local. Non-local dynamics, especially
Landau dam... | 9902331v1 |
2000-04-05 | A consistent nonperturbative approach to thermal damping-rates | We propose a nonperturbative scheme for the calculation of thermal
damping-rates using exact renormalization group (RG)-equations. Special
emphasis is put on the thermal RG where first results for the rate were given
in M. Pietroni, Phys. Rev. Lett. 81 (1998), 2424. We point out that in order to
obtain a complete resul... | 0004039v2 |
2000-07-07 | Finite pion width effects on the rho--meson | We study the influence of the finite damping width of pions on the in-medium
properties of the rho-meson in an interacting meson gas model at finite
temperature. Using vector dominance also implications on the resulting dilepton
spectra from the decay of the rho-meson are presented. A set of coupled Dyson
equations wit... | 0007070v3 |
2000-08-31 | New Regime for Dense String Networks | We uncover a new transient regime that reconciles the apparent inconsistency
of the Martins Shellard one scale damped string evolution model with the
initial conditions predicted by the Kibble mechanism for string formation in a
second order phase transition. This regime carries (in a short cosmic time
$\sim .1 t_c$) t... | 0008330v1 |
2001-01-25 | The Fermion Boson Interaction Within the Linear Sigma Model at Finite Temperature | We reinvestigate the interaction of massless fermions with massless bosons at
finite temperature. Specifically, we calculate the self-energy of massless
fermions due the interaction with massless bosons at high temperature, which is
the region where thermal effects are maximal. The calculations are concentrated
in the ... | 0101283v3 |
2001-11-02 | Quark Number Susceptibility in Hard Thermal Loop Approximation | We calculate the quark number susceptibility in the deconfined phase of QCD
using the hard thermal loop (HTL) approximation for the quark propagator. This
improved perturbation theory takes into account important medium effects such
as thermal quark masses and Landau damping in the quark-gluon plasma. We
explicitly sho... | 0111022v4 |
2001-12-29 | Damped $\sin(β-α)$ of Higgs couplings and the lightest Higgs production at $γγ$ colliders in MSSM | In the decoupling limit, $M^2_{A^0} \gg M^2_Z$, the heavy CP-even, CP-odd and
charged Higgs boson masses are nearly degenerate, $\sin(\beta-\alpha)$
approaches 1, and the lightest CP-even Higgs boson almost displays the same
properties as the Standard Model Higgs boson. But the stop and sbottom sector
can change this p... | 0112356v1 |
2004-05-31 | Gauge dependence of the fermion quasiparticle poles in hot gauge theories | The gauge dependence of the complex fermion quasiparticle poles corresponding
to soft collective excitations is studied in hot gauge theories at one-loop
order and next-to-leading order in the high-temperature expansion, with a view
towards going beyond the leading order hard thermal loops and resummations
thereof. We ... | 0406002v2 |
2004-11-09 | Numerical investigation of friction in inflaton equations of motion | The equation of motion for the expectation value of a scalar quantum field
does not have the local form that is commonly assumed in studies of
inflationary cosmology. We have recently argued that the true, temporally
non-local equation of motion does not possess a time-derivative expansion and
that the conversion of in... | 0411130v1 |
2006-03-03 | Damping of supernova neutrino transitions in stochastic shock-wave density profiles | Supernova neutrino flavor transitions during the shock wave propagation are
known to encode relevant information not only about the matter density profile
but also about unknown neutrino properties, such as the mass hierarchy (normal
or inverted) and the mixing angle theta_13. While previous studies have
focussed on "d... | 0603033v2 |
2006-08-11 | Constraining SuperWIMPy and Warm Subhalos with Future Submillilensing | We propose to observe QSO-galaxy strong lens systems to give a new constraint
on the damping scale of the initial fluctuations. We find that the future
observation of submilliarc scale astrometric shifts of the multiple lensed
images of QSOs would find \sim 10^{(3-9)} M_{\odot} subhalos inside the
macrolens halo. The s... | 0608126v2 |
2006-11-15 | Time-to-Space Conversion in Neutrino Oscillations | We study the neutrino oscillation problem in the framework of the wave packet
formalism. The neutrino state is described by a packet located initially in a
region S (source) and detected in another region D at a distance R from S. We
examine how the oscillation probability as a function of variable R can be
derived fro... | 0611202v1 |
1991-09-26 | The Damping of Energetic Gluons and Quarks in High-Temperature QCD | When a gluon or a quark is sent through the hot QCD plasma it can be absorbed
into the ambient heat bath and so can acquire an effective lifetime. At high
temperatures and for weak couplings the inverse lifetime, or damping rate, for
energetic quarks and transverse gluons, (those whose momenta satisfy $|\p| \gg
gT$) is... | 9109051v1 |
1998-09-11 | Damping and reaction rates and wave function renormalization of fermions in hot gauge theories | We examine the relation between the damping rate of a chiral fermion mode
propagating in a hot plasma and the rate at which the mode approaches
equilibrium. We show how these two quantities, obtained from the imaginary part
of the fermion self-energy, are equal when the reaction rate is defined using
the appropriate wa... | 9809083v2 |
2003-12-28 | A mechanism of the large-scale damping in the CMB anisotropy | We present a mechanism through which a certain class of short-distance cutoff
affects the CMB anisotropies at large angular scales. Our analysis is performed
in two steps. The first is given in an intuitive way, using the property of the
inflationary universe that quantum fluctuations of an inflaton field become
classi... | 0312298v7 |
2005-03-03 | Scalar field perturbations of the Schwarzschild black hole in the Gödel Universe | We investigate the scalar field perturbations of the 4+1-dimensional
Schwarzschild black hole immersed in a G\"{o}del Universe, described by the
Gimon-Hashimoto solution.This may model the influence of the possible rotation
of the Universe upon the radiative processes near a black hole. In the regime
when the scale par... | 0503029v2 |
2005-08-25 | The Dynamics of Small Instanton Phase Transitions | The small instanton transition of a five-brane colliding with one end of the
S1/Z2 interval in heterotic M-theory is discussed, with emphasis on the
transition moduli, their potential function and the associated non-perturbative
superpotential. Using numerical methods, the equations of motion of these
moduli coupled to... | 0508190v2 |
2006-11-21 | Renormalization group study of damping in nonequilibrium field theory | In this paper we shall study whether dissipation in a $\lambda\phi^{4}$ may
be described, in the long wavelength, low frequency limit, with a simple Ohmic
term $\kappa\dot{\phi}$, as it is usually done, for example, in studies of
defect formation in nonequilibrium phase transitions. We shall obtain an
effective theory ... | 0611222v1 |
2006-02-16 | Exit from a basin of attraction for stochastic weakly damped nonlinear Schrödinger equations | We consider weakly damped nonlinear Schr\"odinger equations perturbed by a
noise of small amplitude. The small noise is either complex and of additive
type or real and of multiplicative type. It is white in time and colored in
space. Zero is an asymptotically stable equilibrium point of the deterministic
equations. We ... | 0602350v1 |
2006-06-30 | Uniform attractors for non-autonomous wave equations with nonlinear damping | We consider dynamical behavior of non-autonomous wave-type evolutionary
equations with nonlinear damping, critical nonlinearity, and time-dependent
external forcing which is translation bounded but not translation compact
(i.e., external forcing is not necessarily time-periodic, quasi-periodic or
almost periodic). A su... | 0606776v1 |
2001-04-17 | Scattering and radiation damping in gyroscopic Lorentz electrodynamic | Relativistic massive Lorentz electrodynamics (LED) is studied in a
``gyroscopic setup'' where the electromagnetic fields and the particle spin are
the only dynamical degrees of freedom.
A rigorous proof of the global existence and uniqueness of the dynamics is
given for essentially the whole range of field strengths ... | 0104023v2 |
2002-06-18 | Hamiltonian and Linear-Space Structure for Damped Oscillators: I. General Theory | The phase space of $N$ damped linear oscillators is endowed with a bilinear
map under which the evolution operator is symmetric. This analog of
self-adjointness allows properties familiar from conservative systems to be
recovered, e.g., eigenvectors are "orthogonal" under the bilinear map and obey
sum rules, initial-va... | 0206026v2 |
2002-06-17 | Hamiltonian and Linear-Space Structure for Damped Oscillators: II. Critical Points | The eigenvector expansion developed in the preceding paper for a system of
damped linear oscillators is extended to critical points, where eigenvectors
merge and the time-evolution operator $H$ assumes a Jordan-block structure. The
representation of the bilinear map is obtained in this basis. Perturbations
$\epsilon\De... | 0206027v2 |
2004-02-24 | Classical harmonic oscillator with Dirac-like parameters and possible applications | We obtain a class of parametric oscillation modes that we call K-modes with
damping and absorption that are connected to the classical harmonic oscillator
modes through the "supersymmetric" one-dimensional matrix procedure similar to
relationships of the same type between Dirac and Schroedinger equations in
particle ph... | 0402065v2 |
2000-02-22 | Front motion for phase transitions in systems with memory | We consider the Allen-Cahn equations with memory (a partial
integro-differential convolution equation). The prototype kernels are
exponentially decreasing functions of time and they reduce the
integrodifferential equation to a hyperbolic one, the damped Klein-Gordon
equation. By means of a formal asymptotic analysis we... | 0002039v1 |
2002-03-01 | Excitation of travelling multibreathers in anharmonic chains | We study the dynamics of the "externally" forced and damped Fermi-Pasta-Ulam
(FPU) 1D lattice. The forcing has the spatial symmetry of the Fourier mode with
wavenumber p and oscillates sinusoidally in time with the frequency omega. When
omega is in the phonon band, the p-mode becomes modulationally unstable above a
cri... | 0203002v1 |
2003-01-15 | Resonant triad dynamics in weakly damped Faraday waves with two-frequency forcing | Many of the interesting patterns seen in recent multi-frequency Faraday
experiments can be understood on the basis of three-wave interactions (resonant
triads). In this paper we consider two-frequency forcing and focus on a
resonant triad that occurs near the bicritical point where two pattern-forming
modes with distin... | 0301015v1 |
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