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47
2003-10-28
Chemical Abundances in the Damped Lya Systems
I introduce and review the data and analysis techniques used to measure abundances in the damped Lya systems, quasar absorption-line systems associated with galaxies in the early Universe. The observations and issues associated with their abundance analysis are very similar to those of the Milky Way's interstellar medi...
0310814v1
2004-08-10
Cosmic Ray Scattering and Streaming in Compressible Magnetohydrodynamic 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. Using quasilinear theory we calculate gyroresonance with MHD modes (Al...
0408172v1
2004-12-14
Radiative Effects on Particle Acceleration in Electromagnetic Dominated Outflows
Plasma outflows from gamma-ray bursts (GRB), pulsar winds, relativistic jets, and ultra-intense laser targets radiate high energy photons. However, radiation damping is ignored in conventional PIC simulations. In this letter, we study the radiation damping effect on particle acceleration via Poynting fluxes in two-and-...
0412310v3
2005-09-16
Damped Lyman alpha Systems
Observations of damped Lyman alpha systems offer a unique window on the neutral-gas reservoirs that gave rise to galaxies at high redshifts. This review focuses on critical properties such as the H I and metal content of the gas and on independent evidence for star formation. Together, these provide an emerging picture...
0509481v2
2005-11-11
Oscillation mode lifetimes in ksi Hydrae: Will strong mode damping limit asteroseismology of red giant stars?
We introduce a new method to measure frequency separations and mode lifetimes of stochastically excited and damped oscillations, so-called solar-like oscillations. Our method shows that velocity data of the red giant star ksi Hya (Frandsen et al. 2002) support a large frequency separation between modes of roughly 7 mic...
0511344v1
1996-12-14
Nonlinear Landau damping in collisionless plasma and inviscid fluid
The evolution of an initial perturbation in Vlasov plasma is studied in the intrinsically nonlinear long-time limit dominated by the effects of particle trapping. After the possible transient linear exponential Landau damping, the evolution enters into a universal regime with an algebraically damped electric field, $E\...
9612021v1
1998-03-05
On how a joint interaction of two innocent partners (smooth advection & linear damping) produces a strong intermittency
Forced advection of passive scalar by a smooth $d$-dimensional incompressible velocity in the presence of a linear damping is studied. Acting separately advection and dumping do not lead to an essential intermittency of the steady scalar statistics, while being mixed together produce a very strong non-Gaussianity in th...
9803007v1
1999-02-05
Nonlinear Dynamics of A Damped Magnetic Oscillator
We consider a damped magnetic oscillator, consisting of a permanent magnet in a periodically oscillating magnetic field. A detailed investigation of the dynamics of this dissipative magnetic system is made by varying the field amplitude $A$. As $A$ is increased, the damped magnetic oscillator, albeit simple looking, ex...
9902005v1
1996-09-03
Mode damping in a commensurate monolayer solid
The normal modes of a commensurate monolayer solid may be damped by mixing with elastic waves of the substrate. This was shown by B. Hall et al., Phys. Rev. B 32, 4932 (1985), for perpendicular adsorbate vibrations in the presence of an isotropic elastic medium. That work is generalized with an elastic continuum theory...
9609032v1
1997-12-08
Collective oscillations in superconductors revisited
In the recent paper Ohashi and Takada (OT) made statements that in the clean limit considered by us (AV) in 1975, weakly damped collective oscillations in superconductors do not exist due to the Landau damping and their spectrum differs from that obtained in AV. In this Comment we would like to note that these statemen...
9712086v1
1999-01-11
Vortex motion in superconducting YBCO inferred from the damping of the oscillations of a levitating magnetic microsphere
The damping of the oscillations of a small permanent magnet (spherical shape, radius 0.1 mm) levitating between two parallel YBCO surfaces is measured as a function of oscillation amplitude and temperature. The losses in the samples (epitaxial thin films, bulk granular and bulk melt-textured) are analyzed in terms of o...
9901085v1
1999-10-07
On the relative positions of the $2Δ$ peaks in Raman and tunneling spectra of d-wave superconductors
We study $B_{1g}$ Raman intensity $R(\Omega)$ and the density of states $N(\omega)$ in isotropic 2D d-wave superconductors. For an ideal gas, $R(\Omega)$ and $N(\omega)$ have sharp peaks at $\Omega =2\Delta$ and $\omega =\Delta$, respectively, where $\Delta$ is the maximum value of the gap. We study how the peak posi...
9910090v1
1999-11-22
Two-fluid hydrodynamics of a Bose gas including damping from normal fluid transport coefficients
We extend our recent work on the two-fluid hydrodynamics of the condensate and non-condensate in a trapped Bose gas by including the dissipation associated with viscosity and thermal conduction. For purposes of illustration, we consider the hydrodynamic modes in the case of a uniform Bose gas. A finite thermal conducti...
9911336v1
2000-03-31
Kinetic Theory of Collective Excitations and Damping in Bose-Einstein Condensed Gases
We calculate the frequencies and damping rates of the low-lying collective modes of a Bose-Einstein condensed gas at nonzero temperature. We use a complex nonlinear Schr\"odinger equation to determine the dynamics of the condensate atoms, and couple it to a Boltzmann equation for the noncondensate atoms. In this manner...
0003517v1
2000-09-01
The broad Brillouin doublets and central peak of KTaO_3
The incipient ferroelectric KTaO3 presents low-T Brillouin spectra anomalies,e.g. a broad central peak (CP), and some additional Brillouin doublets (BD), whose origin is interpreted in terms of phonon-density fluctuation processes. A parameterisation from new extensive high-resolution neutron-scattering measurements is...
0009012v1
2001-01-15
Temperature Dependence of Damping and Frequency Shifts of the Scissors Mode of a trapped Bose-Einstein Condensate
We have studied the properties of the scissors mode of a trapped Bose-Einstein condensate of $^{87}$Rb atoms at finite temperature. We measured a significant shift in the frequency of the mode below the hydrodynamic limit and a strong dependence of the damping rate as the temperature increased. We compared our damping ...
0101213v2
2001-03-16
Gap Anisotropy and de Haas-van Alphen Effect in Type-II Superconductors
We present a theoretical study on the de Haas-van Alphen (dHvA) oscillation in the vortex state of type-II superconductors, with a special focus on the connection between the gap anisotropy and the oscillation damping. Numerical calculations for three different gap structures clearly indicate that the average gap along...
0103336v3
2001-04-10
Quantum phase transitions and collective modes in d-wave superconductors
Fluctuations near second-order quantum phase transitions in d-wave superconductors can cause strong damping of fermionic excitations, as observed in photoemission experiments. The damping of the gapless nodal quasiparticles can arise naturally in the quantum-critical region of a transition with an additional spin-singl...
0104176v1
2002-04-11
Nonequilibrium relaxation in neutral BCS superconductors: Ginzburg-Landau approach with Landau damping in real time
We present a field-theoretical method to obtain consistently the equations of motion for small amplitude fluctuations of the order parameter directly in real time for a homogeneous, neutral BCS superconductor. This method allows to study the nonequilibrium relaxation of the order parameter as an initial value problem. ...
0204239v2
2002-05-21
Linear spin waves in a trapped Bose gas
An ultra-cold Bose gas of two-level atoms can be thought of as a spin-1/2 Bose gas. It supports spin-wave collective modes due to the exchange mean field. Such collective spin oscillations have been observed in recent experiments at JILA with ${}^{87}$Rb atoms confined in a harmonic trap. We present a theory of the spi...
0205450v1
2002-08-02
Landau damping of transverse quadrupole oscillations of an elongated Bose-Einstein condensate
We study the interaction between low-lying transverse collective oscillations and thermal excitations of an elongated Bose-Einstein condensate by means of perturbation theory. We consider a cylindrically trapped condensate and calculate the transverse elementary excitations at zero temperature by solving the linearized...
0208047v1
2002-08-28
Transverse modes of a cigar-shaped Bose-Einstein condensate
We discuss the collective modes in a harmonically trapped, highly-elongated Bose condensed gas. The transverse breathing mode exhibits a number of interesting features, such as the insensitivity of the condensate mode frequency to the interaction strength, and the closeness of the frequency to that of the non-condensed...
0208567v1
2002-10-31
Stationary quantum statistics of a non-Markovian atom laser
We present a steady state analysis of a quantum-mechanical model of an atom laser. A single-mode atomic trap coupled to a continuum of external modes is driven by a saturable pumping mechanism. In the dilute flux regime, where atom-atom interactions are negligible in the output, we have been able to solve this model wi...
0210688v1
2003-03-23
Damping of micromechanical structures by paramagnetic relaxation
We find that the damping of micromechanical cantilevers is sensitive to the relaxation dynamics of paramagnetic ions contained within the levers. We measure cantilevers containing paramagnetic Mn ions as a function of temperature, magnetic field, and the vibrational mode of the lever and find that the levers damping is...
0303489v1
2003-06-03
Local Relaxation and Collective Stochastic Dynamics
Damping and thermal fluctuations have been introduced to collective normal modes of a magnetic system in recent modeling of dynamic thermal magnetization processes. The connection between this collective stochastic dynamics and physical local relaxation processes is investigated here. A system of two coupled magnetic g...
0306047v1
2003-10-09
Direct measurement of molecular stiffness and damping in confined water layers
We present {\em direct} and {\em linear} measurements of the normal stiffness and damping of a confined, few molecule thick water layer. The measurements were obtained by use of a small amplitude (0.36 $\textrm{\AA}$), off-resonance Atomic Force Microscopy (AFM) technique. We measured stiffness and damping oscillations...
0310219v1
2004-03-08
Mean-field magnetization relaxation in conducting ferromagnets
Collective ferromagnetic motion in a conducting medium is damped by the transfer of the magnetic moment and energy to the itinerant carriers. We present a calculation of the corresponding magnetization relaxation as a linear-response problem for the carrier dynamics in the effective exchange field of the ferromagnet. I...
0403224v2
2004-04-05
Low-temperature specific heat of real crystals: Possibility of leading contribution of optical and short-wavelength acoustical vibrations
We point out that the repeatedly reported glass-like properties of crystalline materials are not necessarily associated with localized (or quasilocalized) excitations. In real crystals, optical and short-wavelength acoustical vibrations remain damped due to defects down to zero temperature. If such a damping is frequen...
0404063v4
2004-04-20
Decoherence processes during active manipulation of excitonic qubits in semiconductor quantum dots
Using photoluminescence spectroscopy, we have investigated the nature of Rabi oscillation damping during active manipulation of excitonic qubits in self-assembled quantum dots. Rabi oscillations were recorded by varying the pulse amplitude for fixed pulse durations between 4 ps and 10 ps. Up to 5 periods are visible, m...
0404465v1
2004-05-02
Spin Dynamics and Multiple Reflections in Ferromagnetic Film in Contact with Normal Metal Layers
Spin dynamics of a metallic ferromagnetic film imbedded between normal metal layers is studied using the spin-pumping theory of Tserkovnyak et al. [Phys. Rev. Lett. 88, 117601 (2002)]. The scattering matrix for this structure is obtained using a spin-dependent potential with quantum well in the ferromagnetic region. Ow...
0405020v1
2004-06-18
Spin pumping and magnetization dynamics in ferromagnet-Luttinger liquid junctions
We study spin transport between a ferromagnet with time-dependent magnetization and a conducting carbon nanotube or quantum wire, modeled as a Luttinger liquid. The precession of the magnetization vector of the ferromagnet due for instance to an outside applied magnetic field causes spin pumping into an adjacent conduc...
0406437v1
2004-07-29
From subdiffusion to superdiffusion of particles on solid surfaces
We present a numerical and partially analytical study of classical particles obeying a Langevin equation that describes diffusion on a surface modeled by a two dimensional potential. The potential may be either periodic or random. Depending on the potential and the damping, we observe superdiffusion, large-step diffusi...
0407781v1
2004-08-18
Theory of Magnetic Polaron
The concept of magnetic polaron is analysed and developed to elucidate the nature of itinerant charge carrier states in magnetic semiconductors and similar complex magnetic materials. By contrasting the scattering and bound states of carriers within the $s-d$ exchange model, the nature of bound states at finite tempera...
0408404v2
2004-09-27
Dephasing and delay time fluctuations in the chaotic scattering of a quantum particle weakly coupled to a complicated background
Effect of a complicated many-body environment is analyzed on the chaotic motion of a quantum particle in a mesoscopic ballistic structure. The dephasing and absorption phenomena are treated on the same footing in the framework of a schematic microscopic model. The single-particle doorway resonance states excited in the...
0409690v1
2004-10-30
Dynamics of Domain Wall in a Biaxial Ferromagnet With Spin-torque
The dynamics of the domain wall (DW) in a biaxial ferromagnet interacting with a spin-polarized current are described by sine-gordon (SG) equation coupled with Gilbert damping term in this paper. Within our frame-work of this model, we obtain a threshold of the current in the motion of a single DW with the perturbation...
0411005v3
2005-01-18
Damping effects and the metal-insulator transition in the two-dimensional electron gas
The damping of single-particle degrees of freedom in strongly correlated two-dimensional Fermi systems is analyzed. Suppression of the scattering amplitude due to the damping effects is shown to play a key role in preserving the validity of the Landau-Migdal quasiparticle picture in a region of a phase transition, asso...
0501427v2
2005-04-17
Dynamics of thermoelastic thin plates: A comparison of four theories
Four distinct theories describing the flexural motion of thermoelastic thin plates are compared. The theories are due to Chadwick, Lagnese and Lions, Simmonds, and Norris. Chadwick's theory requires a 3D spatial equation for the temperature but is considered the most accurate as the others are derivable from it by diff...
0504412v1
2005-04-29
Probing temperature and damping rates in Bose-Einstein condensates using ultraslow light experiments
We propose a method to probe Landau and Beliaev processes in dilute trapped atomic condensates with a multiple state structure using ultraslow light experimental configurations. Under certain conditions, damping rates from these collisional processes are directly proportional to the dephasing rates, making it possible ...
0504784v2
2005-05-23
Anharmonic vs. relaxational sound damping in glasses: I. Brillouin scattering from densified silica
This series discusses the origin of sound damping and dispersion in glasses. In particular, we address the relative importance of anharmonicity versus thermally activated relaxation. In this first article, Brillouin-scattering measurements of permanently densified silica glass are presented. It is found that in this ca...
0505558v3
2005-05-23
Anharmonic vs. relaxational sound damping in glasses: II. Vitreous silica
The temperature dependence of the frequency dispersion in the sound velocity and damping of vitreous silica is reanalyzed. Thermally activated relaxation accounts for the sound attenuation observed above 10 K at sonic and ultrasonic frequencies. Its extrapolation to the hypersonic regime reveals that the anharmonic cou...
0505560v2
2005-06-06
Heat Bath Approach to Landau Damping and Pomeranchuk Quantum Critical Points
We study the problem of the damping of collective modes close to a Pomeranchuk quantum critical point in a Fermi liquid. In analogy with problems in dissipative open quantum systems, we derive the Landau damping of a Fermi liquid by integrating out a macroscopic number of degrees of freedom from a generating functional...
0506146v3
2005-07-01
Measurement of Dissipation of a Three-Level rf SQUID Qubit
The dissipation-induced relaxation (T_1) time of a macroscopic quantum system - a \{lambda}-type three-level rf SQUID flux qubit weakly coupled to control and readout circuitry (CRC) - is investigated via time-domain measurement. The measured interwell relaxation time of the qubit's first excited state, T_1=3.45+/-0.06...
0507008v1
2005-09-19
Interaction effects on magnetooscillations in a two-dimensional electron gas
Motivated by recent experiments, we study the interaction corrections to the damping of magnetooscillations in a two-dimensional electron gas (2DEG). We identify leading contributions to the interaction-induced damping which are induced by corrections to the effective mass and quantum scattering time. The damping facto...
0509463v2
2005-10-31
Time-Resolved Spin Torque Switching and Enhanced Damping in Py/Cu/Py Spin-Valve Nanopillars
We report time-resolved measurements of current-induced reversal of a free magnetic layer in Py/Cu/Py elliptical nanopillars at temperatures T = 4.2 K to 160 K. Comparison of the data to Landau-Lifshitz-Gilbert macrospin simulations of the free layer switching yields numerical values for the spin torque and the Gilbert...
0510798v2
2005-12-20
Damping of zero sound in Luttinger liquids
We calculate the damping gamma_q of collective density oscillations (zero sound) in a one-dimensional Fermi gas with dimensionless forward scattering interaction F and quadratic energy dispersion k^2 / 2 m at zero temperature. For wave-vectors | q| /k_F small compared with F we find to leading order gamma_q = v_F^{-1} ...
0512494v4
2006-04-11
Damping and dispersion of oscillating modes of a multicomponent ionic mixture in a magnetic field
The collective-mode spectrum of a multicomponent magnetized ionic mixture for small wave number k is studied with the use of magnetohydrodynamics and formal kinetic theory. Apart from the usual thermal and diffusive modes, the spectrum contains a set of four oscillating modes. By evaluating the k^2 contributions to the...
0604272v1
2006-07-06
Low energy theory of a single vortex and electronic quasiparticles in a d-wave superconductor
We highlight the properties of a simple model (contained in our recent work) of the quantum dynamics of a single point vortex interacting with the nodal fermionic quasiparticles of a d-wave superconductor. We describe the renormalization of the vortex motion by the quasiparticles: at T=0, the quasiparticles renormalize...
0607137v2
2006-09-18
General Form of Magnetization Damping: Magnetization dynamics of a spin system evolving nonadiabatically and out of equilibrium
Using an effective Hamiltonian including the Zeeman and internal interactions, we describe the quantum theory of magnetization dynamics when the spin system evolves non-adiabatically and out of equilibrium. The Lewis-Riesenfeld dynamical invariant method is employed along with the Liouville-von Neumann equation for the...
0609431v2
2005-08-23
Investigations of Process Damping Forces in Metal Cutting
Using finite element software developed for metal cutting by Third Wave Systems we investigate the forces involved in chatter, a self-sustained oscillation of the cutting tool. The phenomena is decomposed into a vibrating tool cutting a flat surface work piece, and motionless tool cutting a work piece with a wavy surfa...
0508102v1
1999-09-27
R-Modes in Superfluid Neutron Stars
The analogs of r-modes in superfluid neutron stars are studied here. These modes, which are governed primarily by the Coriolis force, are identical to their ordinary-fluid counterparts at the lowest order in the small angular-velocity expansion used here. The equations that determine the next order terms are derived an...
9909084v1
2001-02-08
Cyclotron damping and Faraday rotation of gravitational waves
We study the propagation of gravitational waves in a collisionless plasma with an external magnetic field parallel to the direction of propagation. Due to resonant interaction with the plasma particles the gravitational wave experiences cyclotron damping or growth, the latter case being possible if the distribution fun...
0102031v2
2000-08-18
Fabrication Process of Rounded Damped Detuned Structure
Following the successful design and fabrication of Damped Detuned Structures (DDS), the JLC/NLC linear collider project advanced to Rounded Damped Detuned Structures (RDDS) with curved cross section of the cavity shape for increased shunt impedance. Various advanced techniques for fabricating RDDS1 disks comparing to t...
0008034v1
2000-08-18
Meeting Tight Frequency Requirement of Rounded Damped Detuned Structure
Following successful design and fabrication of damped detuned structures, the R&D for the accelerating structures of the NLC/JLC linear collider project proceeded to studies of Rounded Damped Detuned Structure with curved cross section of the cavity shape for increased shunt impedance. The important features of the str...
0008035v1
1992-03-16
Comment on ``Damping of energetic gluons and quarks in high-temperature QCD''
Burgess and Marini have recently pointed out that the leading contribution to the damping rate of energetic gluons and quarks in the QCD plasma, given by $\gamma=c g^2\ln(1/g)T$, can be obtained by simple arguments obviating the need of a fully resummed perturbation theory as developed by Braaten and Pisarski. Their ca...
9203211v1
1995-02-16
The Infrared Sensitivity of Screening and Damping in a Quark-Gluon Plasma
All the next-to-leading order contributions to the quasi-particle dispersion laws of a quark-gluon plasma which due to infrared singularities are sensitive to the magnetic-mass scale are calculated using Braaten-Pisarski resummation. These relative-order-$g\ln(g)$ corrections are shown here to generally contribute to t...
9502324v1
1997-10-30
Damping rate for transverse gluons with finite soft momentum in hot QCD
We calculate the damping rate for transverse gluons with {\nineti finite} soft momentum to leading order in perturbative hot QCD. The internal momenta of the one-loop contributing diagrams are soft. This means we have to use effective vertices and propagators which incorporate the so-called hard thermal loops. We expan...
9710549v2
1998-07-21
An infrared singularity in the damping rate for longitudinal gluons in hot QCD
We calculate $\gamma_l(0)$, the damping rate for longitudinal on-shell gluons with zero momentum in hot QCD using the hard-thermal-loop (htl) scheme. We find it to be divergent in the infrared, which means that in this scheme $\gamma_l(0)$ is different from $\gamma_t(0)$, the corresponding damping rate for transverse g...
9807439v2
1998-09-25
Damping rates in the MSSM and electroweak baryogenesis
We present an analysis of the thermalization rate of Higgsinos and winos based on the imaginary part of the two-point Green function in the {\it unbroken} phase of the MSSM. We use improved propagators including resummation of hard thermal loops and the thermalization rate is computed at the one-loop level in the high ...
9809529v1
2006-10-27
The soft fermion dispersion relation at next-to-leading order in hot QED
We study next-to-leading order contributions to the soft static fermion dispersion relation in hot QED. We derive an expression for the complete next-to-leading order contribution to the retarded fermion self-energy. The real and imaginary parts of this expression give the next-to-leading order contributions to the mas...
0610372v1
2007-03-26
Preheating and Affleck-Dine leptogenesis after thermal inflation
Previously, we proposed a model of low energy Affleck-Dine leptogenesis in the context of thermal inflation. The lepton asymmetry is generated at the end of thermal inflation, which occurs at a relatively low energy scale with the Hubble parameter somewhere in the range $1 \keV \lesssim H \lesssim 1 \MeV$. Thus Hubble ...
0703275v1
2002-08-31
Neutrino damping rate at finite temperature and density
A first principle derivation is given of the neutrino damping rate in real-time thermal field theory. Starting from the discontinuity of the neutrino self energy at the two loop level, the damping rate can be expressed as integrals over space phase of amplitudes squared, weighted with statistical factors that account f...
0209006v1
2004-10-20
Ergodicity for the weakly damped stochastic non-linear Schrödinger equations
We study a damped stochastic non-linear Schr\"{o}dinger (NLS) equation driven by an additive noise. It is white in time and smooth in space. Using a coupling method, we establish convergence of the Markovian transition semi-group toward a unique invariant probability measure. This kind of method was originally developp...
0410443v2
2006-07-30
Non-autonomous dynamics of wave equations with nonlinear damping and critical nonlinearity
The authors consider non-autonomous dynamical behavior of wave-type evolutionary equations with nonlinear damping and critical nonlinearity. These type of waves equations are formulated as non-autonomous dynamical systems (namely, cocycles). A sufficient and necessary condition for the existence of pullback attractors ...
0607774v3
2000-09-28
Quantization of Damped Harmonic Oscillator, Thermal Field Theories and q-Groups
We study the canonical quantization of the damped harmonic oscillator by resorting to the realization of the q-deformation of the Weyl-Heisenberg algebra (q-WH) in terms of finite difference operators. We relate the damped oscillator hamiltonian to the q-WH algebra and to the squeezing generator of coherent states theo...
0009036v1
2001-11-14
Soliton-radiation coupling in the parametrically driven, damped nonlinear Schrödinger equation
We use the Riemann-Hilbert problem to study the interaction of the soliton with radiation in the parametrically driven, damped nonlinear Schr\"odinger equation. The analysis is reduced to the study of a finite-dimensional dynamical system for the amplitude and phase of the soliton and the complex amplitude of the long-...
0111034v1
2005-10-24
Stability of a nonlinear oscillator with random damping
A noisy damping parameter in the equation of motion of a nonlinear oscillator renders the fixed point of the system unstable when the amplitude of the noise is sufficiently large. However, the stability diagram of the system can not be predicted from the analysis of the moments of the linearized equation. In the case o...
0510063v1
2006-10-20
Vibration of Generalized Double Well Oscillators
We have applied the Melnikov criterion to examine a global homoclinic bifurcation and transition to chaos in a case of a double well dynamical system with a nonlinear fractional damping term and external excitation. The usual double well Duffing potential having a negative square term and positive quartic term has been...
0610052v1
1998-06-18
Relativity Damps OPEP in Nuclear Matter
Using a relativistic Dirac-Brueckner analysis the OPEP contribution to the ground state energy of nuclear matter is studied. In the study the pion is derivative-coupled. We find that the role of the tensor force in the saturation mechanism is substantially reduced compared to its dominant role in a usual nonrelativisti...
9806054v1
1999-07-05
Damping of IVGDR - Fermi-liquid or Fermi-gas ?
Collisional relaxation rates of collective modes in nuclei are calculated using the Levinson equation for the reduced density matrix with a memory dependent collision term. Linearizing the collision integral two contribution have to be distinguished, the one from the quasiparticle energy and the one from occupation fac...
9907012v1
2001-01-08
Collisional Damping of Giant Monopole and Quadrupole Resonances
Collisional damping widths of giant monopole and quadrupole excitations for $^{120}$Sn and $^{208}$Pb at zero and finite temperatures are calculated within Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Skyrme and Gogny forces, and are compa...
0101016v1
1996-12-08
Towards a Simple Model of Compressible Alfvenic Turbulence
A simple model collisionless, dissipative, compressible MHD (Alfvenic) turbulence in a magnetized system is investigated. In contrast to more familiar paradigms of turbulence, dissipation arises from Landau damping, enters via nonlinearity, and is distributed over all scales. The theory predicts that two different regi...
9612005v2
1998-10-01
Mode-coupling and nonlinear Landau damping effects in auroral Farley-Buneman turbulence
The fundamental problem of Farley-Buneman turbulence in the auroral $E$-region has been discussed and debated extensively in the past two decades. In the present paper we intend to clarify the different steps that the auroral $E$-region plasma has to undergo before reaching a steady state. The mode-coupling calculation...
9810062v1
2000-08-20
Fabrication and Tolerance Issues and their Influence on Multi-Bunch Bbu and Emittance Dilution in the Construction of X-Band RDDS Linacs for the NLC
The main linacs of the Next Linear Collider (NLC) will contain several thousand X-band RDDS (Rounded Damped Detuned Structures). The transverse wakefield in the structures is reduced by detuning the modal frequencies such that they destructively interfere and by four damping manifolds per structure which provide weak d...
0008198v1
2003-09-17
A New Damping Mechanism in Non-linear Bubble Dynamics
Non-linear equations of radial motion of a gas bubble in a compressible viscous liquid have been modified considering effects of viscosity and compressibility more complete than all previous works. A new set of equations has been derived including new terms resulted from consideration of the viscosity and compressibili...
0309080v1
2003-11-26
Eigenvector Expansion and Petermann Factor for Ohmically Damped Oscillators
Correlation functions $C(t) \sim <\phi(t)\phi(0)>$ in ohmically damped systems such as coupled harmonic oscillators or optical resonators can be expressed as a single sum over modes $j$ (which are not power-orthogonal), with each term multiplied by the Petermann factor (PF) $C_j$, leading to "excess noise" when $|C_j| ...
0311127v2
2004-04-02
DAFNE injection system upgrade
High luminosity in DAFNE needs very high electron and positron currents stored. A full energy (510 MeV) injection system composed by a full energy electron and positron linac and an accumulator-damping ring is presently used. The electron and positron beams, alternatively accelerated by the linac, are injected and stac...
0404010v1
2004-05-05
Langmuir wave self-focusing versus decay instability
Electron trapping in a finite amplitude Langmuir wave (LW) leads to a frequency shift, \Delta\omega_{TP} < 0, and reduced Landau damping. These may lead to modulational instability. Its growth rate and damping threshold, due to escape of trapped electrons at rate \nu, are calculated for the first time in the short wave...
0405015v1
2005-06-16
Mesoscale Quantization and Self-Organized Stability
In the world of technology, one of the most important forms of friction is that of rolling friction. Yet it is one of the least studied of all the known forms of energy dissipation. In the present experiments we investigate the oscillatory free-decay of a rigid cube, whose side-length is less than the diameter of the r...
0506143v1
2006-10-31
Ultimate parameters of the photon collider at the ILC
At linear colliders, the e+e- luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). While in gamma-gamma collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In present damping rings designs, nominal DR ...
0610285v1
2006-04-27
On the weak solutions of the McKendrick equation: Existence of demography cycles
We develop the qualitative theory of the solutions of the McKendrick partial differential equation of population dynamics. We calculate explicitly the weak solutions of the McKendrick equation and of the Lotka renewal integral equation with time and age dependent birth rate. Mortality modulus is considered age dependen...
0604035v2
1999-03-05
Exact Diagonalization of Two Quantum Models for the Damped Harmonic Oscillator
The damped harmonic oscillator is a workhorse for the study of dissipation in quantum mechanics. However, despite its simplicity, this system has given rise to some approximations whose validity and relation to more refined descriptions deserve a thorough investigation. In this work, we apply a method that allows us to...
9903022v2
1999-04-06
Nonclassical correlations in damped quantum solitons
Using cumulant expansion in Gaussian approximation, the internal quantum statistics of damped soliton-like pulses in Kerr media are studied numerically, considering both narrow and finite bandwidth spectral pulse components. It is shown that the sub-Poissonian statistics can be enhanced, under certain circumstances, by...
9904017v2
1999-04-19
Quantum theory of fluctuations in a cold damped accelerometer
We present a quantum network approach to real high sensitivity measurements. Thermal and quantum fluctuations due to active as well as passive elements are taken into account. The method is applied to the analysis of the capacitive accelerometer using the cold damping technique, developed for fundamental physics in spa...
9904073v2
2000-07-04
Stochastic limit approximation for rapidly decaying systems
The stochastic limit approximation method for ``rapid'' decay is presented, where the damping rate \gamma is comparable to the system frequency \Omega, i.e., \gamma \sim \Omega, whereas the usual stochastic limit approximation is applied only to the weak damping situation \gamma << \Omega. The key formulas for rapid de...
0007007v2
2000-08-01
Full mechanical characterization of a cold damped mirror
We describe an experiment in which we have used a cold damping feedback mechanism to reduce the thermal noise of a mirror around its mechanical resonance frequency. The monitoring of the brownian motion of the mirror allows to apply an additional viscous force without any thermal fluctuations associated. This scheme ha...
0008004v1
2003-11-05
Exact decoherence to pointer states in free open quantum systems is universal
In this paper it is shown that exact decoherence to minimal uncertainty Gaussian pointer states is generic for free quantum particles coupled to a heat bath. More specifically, the paper is concerned with damped free particles linearly coupled under product initial conditions to a heat bath at arbitrary temperature, wi...
0311022v3
2004-07-30
Kraus representation of damped harmonic oscillator and its application
By definition, the Kraus representation of a harmonic oscillator suffering from the environment effect, modeled as the amplitude damping or the phase damping, is directly given by a simple operator algebra solution. As examples and applications, we first give a Kraus representation of a single qubit whose computational...
0407263v2
2005-01-31
The non dissipative damping of the Rabi oscillations as a "which-path" information
Rabi oscillations may be viewed as an interference phenomenon due to a coherent superposition of different quantum paths, like in the Young's two-slit experiment. The inclusion of the atomic external variables causes a non dissipative damping of the Rabi oscillations. More generally, the atomic translational dynamics i...
0501181v1
2006-01-12
Driven harmonic oscillator as a quantum simulator for open systems
We show theoretically how a driven harmonic oscillator can be used as a quantum simulator for non-Markovian damped harmonic oscillator. In the general framework, the results demonstrate the possibility to use a closed system as a simulator for open quantum systems. The quantum simulator is based on sets of controlled d...
0601081v2
2007-05-05
Damped Corrections to Inflationary Spectra from a Fluctuating Cutoff
We reconsider trans-Planckian corrections to inflationary spectra by taking into account a physical effect which has been overlooked and which could have important consequences. We assume that the short length scale characterizing the new physics is endowed with a finite width, the origin of which could be found in qua...
0705.0747v1
2007-05-10
Effective temperature and Gilbert damping of a current-driven localized spin
Starting from a model that consists of a semiclassical spin coupled to two leads we present a microscopic derivation of the Langevin equation for the direction of the spin. For slowly-changing direction it takes on the form of the stochastic Landau-Lifschitz-Gilbert equation. We give expressions for the Gilbert damping...
0705.1432v3
2007-05-10
Magnetization oscillations induced by a spin-polarized current in a point-contact geometry: mode hopping and non-linear damping effects
In this paper we study magnetization excitations induced in a thin extended film by a spin-polarized dc-current injected through a point contact in the current-perpendicular-to-plane (CPP) geometry. Using full-scale micromagnetic simulations, we demonstrate that in addition to the oscillations of the propagating wave t...
0705.1515v1
2007-05-27
Amplitude Damping for single-qubit System with single-qubit mixed-state Environment
We study a generalized amplitude damping channel when environment is initially in the single-qubit mixed state. Representing the affine transformation of the generalized amplitude damping by a three-dimensional volume, we plot explicitly the volume occupied by the channels simulatable by a single-qubit mixed-state envi...
0705.3952v3
2007-06-08
Kinetic-Ion Simulations Addressing Whether Ion Trapping Inflates Stimulated Brillouin Backscattering Reflectivities
An investigation of the possible inflation of stimulated Brillouin backscattering (SBS) due to ion kinetic effects is presented using electromagnetic particle simulations and integrations of three-wave coupled-mode equations with linear and nonlinear models of the nonlinear ion physics. Electrostatic simulations of lin...
0706.1236v1
2007-06-29
Driving-dependent damping of Rabi oscillations in two-level semiconductor systems
We propose a mechanism to explain the nature of the damping of Rabi oscillations with increasing driving-pulse area in localized semiconductor systems, and have suggested a general approach which describes a coherently driven two-level system interacting with a dephasing reservoir. Present calculations show that the no...
0706.4372v1
2007-08-06
Collisionsless amplifying of longitudinal electron waves in two-stream plasma
To better understanding the principal features of collisionless damping/growing plasma waves we have implemented a demonstrative calculation for the simplest cases of electron waves in two-stream plasmas with the delta-function type electron velocity distribution function of each of the streams with velocities v(1) and...
0708.0767v1
2007-08-09
The Highly Damped Quasinormal Modes of Extremal Reissner-Nordström and Reissner-Nordström-de Sitter Black Holes
We analyze in detail the highly damped quasinormal modes of $D$-dimensional extremal Reissner-Nordstr$\ddot{\rm{o}}$m and Reissner-Nordstr$\ddot{\rm{o}}$m-de Sitter black holes. We only consider the extremal case where the event horizon and the Cauchy inner horizon coincide. We show that, even though the topology of th...
0708.1333v2
2007-08-28
Resonantly damped surface and body MHD waves in a solar coronal slab with oblique propagation
The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-$\beta$ configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is considered both surface and body waves are able to propagate. When the perpendicular wave...
0708.3783v1
2007-09-11
Teleportation of qubit states through dissipative channels: Conditions for surpassing the no-cloning limit
We investigate quantum teleportation through dissipative channels and calculate teleportation fidelity as a function of damping rates. It is found that the average fidelity of teleportation and the range of states to be teleported depend on the type and rate of the damping in the channel. Using the fully entangled frac...
0709.1662v1
2007-10-03
Global stability of travelling fronts for a damped wave equation with bistable nonlinearity
We consider the damped wave equation \alpha u_tt + u_t = u_xx - V'(u) on the whole real line, where V is a bistable potential. This equation has travelling front solutions of the form u(x,t) = h(x-st) which describe a moving interface between two different steady states of the system, one of which being the global mini...
0710.0794v1