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2011-09-14
On the approximation for singularly perturbed stochastic wave equations
We explore the relation between fast waves, damping and imposed noise for different scalings by considering the singularly perturbed stochastic nonlinear wave equations \nu u_{tt}+u_t=\D u+f(u)+\nu^\alpha\dot{W} on a bounded spatial domain. An asymptotic approximation to the stochastic wave equation is constructed by...
1109.3000v1
2011-09-19
Quasinormal resonances of a massive scalar field in a near-extremal Kerr black hole spacetime
The fundamental resonances of near-extremal Kerr black holes due to massive scalar perturbations are derived {\it analytically}. We show that there exists a critical mass parameter, $\mu_c$, below which increasing the mass $\mu$ of the field increases the oscillation frequency $\Re(\omega)$ of the resonance. On the oth...
1109.4080v1
2011-09-26
Gauge-flation and Cosmic No-Hair Conjecture
Gauge-flation, inflation from non-Abelian gauge fields, was introduced in [1,2]. In this work, we study the cosmic no-hair conjecture in gauge-flation. Starting from Bianchi-type I cosmology and through analytic and numeric studies we demonstrate that the isotropic FLRW inflation is an attractor of the dynamics of the ...
1109.5573v2
2011-09-26
A possible statistical mechanism of anomalous neutrino velocity in OPERA experiment?
The set of kinetic equations describing the process of conversion of a beam of protons into mesons and then to neutrinos is solved. The asymptotic evolution of the density profile of neutrinos is essentially the same as that obtained in the previous version of the note for a simple model of uniformly damped wave-packet...
1109.5727v2
2011-09-28
Local solvability and loss of smoothness of the Navier-Stokes-Maxwell equations with large initial data
Existence of local-in-time unique solution and loss of smoothness of full Magnet-Hydro-Dynamics system (MHD) is considered for periodic initial data. The result is proven using Fujita-Kato's method in $\ell^1$ based (for the Fourier coefficients) functional spaces enabling us to easily estimate nonlinear terms in the s...
1109.6089v1
2011-10-02
On exponential decay rate of semigroup associated with second order linear differential equation in Hilbert space with strong damping operator
We obtain estimate of the exponential decay rate of semigroup associated with second order linear differential equation $u"+Du'+Au=0$ in Hilbert space. We assume that $A$ is a selfadjoint positive definite operator, $D$ is an accretive sectorial operator and $\Ree D\geq\delta A$, $\delta>0$. We obtain a location of the...
1110.0167v1
2011-10-11
Parabolic inverse convection-diffusion-reaction problem solved using an adaptive parametrization
This paper investigates the solution of a parabolic inverse problem based upon the convection-diffusion-reaction equation, which can be used to estimate both water and air pollution. We will consider both known and unknown source location: while in the first case the problem is solved using a projected damped Gauss-New...
1110.2376v1
2011-10-23
Hard x-ray or gamma ray laser by a dense electron beam
A coherent x-ray or gamma ray can be created from a dense electron beam propagating through an intense laser undulator. It is analyzed by using the Landau damping theory which suits better than the conventional linear analysis for the free electron laser, as the electron beam energy spread is high. The analysis suggest...
1110.5077v2
2011-10-30
Dissipation of micro-cantilevers as a function of air pressure and metallic coating
In this letter, we characterize the internal dissipation of coated micro-cantilevers through their mechanical thermal noise. Using a home-made interferometric setup, we achieve a resolution down to 1E-14m/rtHz in the measurement of their deflection. With the use of the fluctuation dissipation theorem and of the Kramers...
1110.6629v1
2011-11-02
Bucket Shaking Stops Bunch Oscillations In The Tevatron
Bunches in the Tevatron are known to exhibit longitudinal oscillations which persist indefinitely. These oscillations are colloquially called "dancing bunches". Although the dancing bunches do not cause single bunch emittance growth or beam loss at injection, it leads to bunch lengthening at collisions. In operations, ...
1111.0612v1
2011-11-10
Exponential suppression of interlayer conductivity in very anisotropic quasi-two-dimensional compounds in high magnetic field
It is shown that in rather strong magnetic field the interlayer electron conductivity is exponentially damped by the Coulomb barrier arising from the formation of polaron around each localized electron state. The theoretical model is developed to describe this effect, and the calculation of the temperature and field de...
1111.2432v1
2011-11-13
Fractional oscillator
We consider the fractional oscillator being a generalization of the conventional linear oscillator in the framework of fractional calculus. It is interpreted as an ensemble average of ordinary harmonic oscillators governed by stochastic time arrow. The intrinsic absorption of the fractional oscillator results from the ...
1111.3060v1
2011-11-25
Teleporting the one-qubit state via two-level atoms with spontaneous emission
We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation...
1111.5964v1
2011-12-02
An application of nonlinear supratransmission to the propagation of binary signals in weakly damped, mechanical systems of coupled oscillators
In the present article, we simulate the propagation of binary signals in semi-infinite, mechanical chains of coupled oscillators harmonically driven at the end, by making use of the recently discovered process of nonlinear supratransmission. Our numerical results ---which are based on a brand-new computational techniqu...
1112.0583v1
2011-12-06
Fragmentation of electric dipole strength in N=82 isotones
Fragmentation of the dipole strength in the N=82 isotones 140Ce, 142Nd and 144Sm is calculated using the second random-phase approximation (SRPA). In comparison with the result of the random-phase approximation (RPA), the SRPA provides the additional damping of the giant dipole resonance and the redistribution of the l...
1112.1231v1
2011-12-06
Generalized hidden Kerr/CFT
We construct a family of vector fields that generate local symmetries in the solution space of low frequency massless field perturbations in the general Kerr geometry. This yields a one-parameter family of SL(2,R)x SL(2,R) algebras. We identify limits in which the SL(2,R)xSL(2,R) algebra contracts to an SL(2,R) symmetr...
1112.1431v2
2011-12-11
Shear viscosity and spin diffusion coefficient of a two-dimensional Fermi gas
Using kinetic theory, we calculate the shear viscosity and the spin diffusion coefficient as well as the associated relaxation times for a two-component Fermi gas in two dimensions, as a function of temperature, coupling strength, polarization, and mass ratio of the two components. It is demonstrated that the minimum v...
1112.2395v2
2011-12-12
On the vanishing electron-mass limit in plasma hydrodynamics in unbounded media
We consider the zero-electron-mass limit for the Navier-Stokes-Poisson system in unbounded spatial domains. Assuming smallness of the viscosity coefficient and ill-prepared initial data, we show that the asymptotic limit is represented by the incompressible Navier-Stokes system, with a Brinkman damping, in the case whe...
1112.2562v1
2011-12-14
Quenched Slonczewski-Windmill in Spin-Torque Vortex-Oscillators
We present a combined analytical and numerical study on double-vortex spin-torque nano-oscillators and describe a mechanism that suppresses the windmill modes. The magnetization dynamics is dominated by the gyrotropic precession of the vortex in one of the ferromagnetic layers. In the other layer the vortex gyration is...
1112.3163v1
2011-12-14
Beam cavity interaction
We begin by giving a description of the rf generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavi...
1112.3203v1
2011-12-17
Asymmetric ac fluxon depinning in a Josephson junction array: A highly discrete limit
Directed motion and depinning of topological solitons in a strongly discrete damped and biharmonically ac-driven array of Josephson junctions is studied. The mechanism of the depinning transition is investigated in detail. We show that the depinning process takes place through chaotization of an initially standing flux...
1112.4083v1
2011-12-20
Effects of helical magnetic fields on the cosmic microwave background
A complete numerical calculation of the temperature anisotropies and polarization of the cosmic microwave background (CMB) in the presence of a stochastic helical magnetic field is presented which includes the contributions due to scalar, vector and tensor modes. The correlation functions of the magnetic field contribu...
1112.4797v1
2011-12-23
Dynamical revival of phase coherence in a many-boson system
We study the quantum dynamics of cold Bose atoms in a double well. It is shown that self-trapping, as well as population oscillations are common phenomena associated to nonlinear interactions. For larger $U/t$, multi-particle tunneling is damped and the quantum dynamics is dominated by the single-particle tunneling. Th...
1112.5494v1
2012-01-15
Triviality of the 2D stochastic Allen-Cahn equation
We consider the stochastic Allen-Cahn equation driven by mollified space-time white noise. We show that, as the mollifier is removed, the solutions converge weakly to 0, independently of the initial condition. If the intensity of the noise simultaneously converges to 0 at a sufficiently fast rate, then the solutions co...
1201.3089v1
2012-01-24
Transverse modes and instabilities of a bunched beam with space charge and resistive wall impedance
Transverse instability of a bunched beam is investigated with synchrotron oscillations, space charge, and resistive wall wakefield taken into account. Boxcar model is used for all-round analysis, and Gaussian distribution is invoked for details. The beam spectrum, instability growth rate and effects of chromaticity are...
1201.5110v1
2012-02-03
Cavity Dynamical Casimir Effect in the presence of a three-level atom
We consider the scenario in which a damped three-level atom in the ladder or V configurations is coupled to a single cavity mode whose vacuum state is amplified by dint of the dynamical Casimir effect. We obtain approximate analytical expressions and exact numerical results for the time-dependent probabilities, demonst...
1202.0772v2
2012-02-11
Statistical reliability and path diversity based PageRank algorithm improvements
In this paper we present new improvement ideas of the original PageRank algorithm. The first idea is to introduce an evaluation of the statistical reliability of the ranking score of each node based on the local graph property and the second one is to introduce the notion of the path diversity. The path diversity can b...
1202.2393v1
2012-02-20
Detectable inertial effects on Brownian transport through narrow pores
We investigate the transport of suspended Brownian particles dc driven along corrugated narrow channels in a regime of finite damping. We demonstrate that inertial corrections cannot be neglected as long as the width of the channel bottlenecks is smaller than an appropriate particle diffusion length, which depends on b...
1202.4362v2
2012-02-21
Discrete solitons in coupled active lasing cavities
We examine the existence and stability of discrete spatial solitons in coupled nonlinear lasing cavities (waveguide resonators), addressing the case of active defocusing media, where the gain exceeds damping in the low-amplitude limit. A new family of stable localized structures is found: these are bright and grey cavi...
1202.4660v2
2012-02-26
On the Fitzhugh-Nagumo model
The initial value problem P0, in all of the space, for the spatio - temporal FitzHugh - Nagumo equations is analyzed. When the reaction kinetics of the model can be outlined by means of piecewise linear approximations, then the solution of P0 is explicitly obtained. For periodic initial data are possible damped travell...
1202.5783v1
2012-02-27
Second-order Price Dynamics: Approach to Equilibrium with Perpetual Arbitrage
The notion that economies should normally be in equilibrium is by now well-established; equally well-established is that economies are almost never precisely in equilibrium. Using a very general formulation, we show that under dynamics that are second-order in time a price system can remain away from equilibrium with p...
1202.5926v1
2012-03-02
Prospects for transient gravitational waves at r-mode frequencies associated with pulsar glitches
Glitches in pulsars are likely to trigger oscillation modes in the fluid interior of neutron stars. We examined these oscillations specifically at r-mode frequencies. The excited r-modes will emit gravitational waves and can have long damping time scales O(minutes - days). We use simple estimates of how much energy the...
1203.0401v1
2012-03-14
Probabilistic representation of fundamental solutions to $\frac{\partial u}{\partial t} = κ_m \frac{\partial^m u}{\partial x^m}$
For the fundamental solutions of heat-type equations of order $n$ we give a general stochastic representation in terms of damped oscillations with generalized gamma distributed parameters. By composing the pseudo-process $X_n$ related to the higher-order heat-type equation with positively skewed stable r.v.'s $T^j_{1/3...
1203.3133v1
2012-03-15
Quantum-memory-assisted entropic uncertainty principle under noise
The measurement outcomes of two incompatible observables on a particle can be precisely predicted when it is maximally entangled with a quantum memory, as quantified recently [Nature Phys. 6, 659 (2010)]. We explore the behavior of the uncertainty relation under the influence of local unital and nonunital noisy channel...
1203.3331v1
2012-03-15
Conditions for the freezing phenomena of geometric measure of quantum discord for arbitrary two-qubit X states under non-dissipative dephasing noises
We study the dynamics of geometric measure of quantum discord (GMQD) under the influences of two local phase damping noises. Consider the two qubits initially in arbitrary X-states, we find the necessary and sufficient conditions for which GMQD is unaffected for a finite period. It is further shown that such results al...
1203.3356v2
2012-03-16
Dynamical Casimir Effect in two-atom cavity QED
We study analytically and numerically the dynamical Casimir effect in a cavity containing two stationary 2-level atoms that interact with the resonance field mode via the Tavis-Cummings Hamiltonian. We determine the modulation frequencies for which the field and atomic excitations are generated and study the correspond...
1203.3776v2
2012-03-20
Role of Bose Statistics in Crystallization and Quantum Jamming
Indistinguishability of particles is a major factor destabilizing crystalline order in Bose systems. We describe this effect in terms of damped quasi-particle modes and in the dual language of Feynman paths, and illustrate it by first-principle simulations of dipolar bosons and bulk condensed helium-four. The first maj...
1203.4447v2
2012-03-30
Escape rate of an active Brownian particle over a potential barrier
We study the dynamics of an active Brownian particle with a nonlinear friction function located in a spatial cubic potential. For strong but finite damping, the escape rate of the particle over the spatial potential barrier shows a nonmonotonic dependence on the noise intensity. We relate this behavior to the fact that...
1203.6814v1
2012-04-05
Phase space reduction of the one-dimensional Fokker-Planck (Kramers) equation
A pointlike particle of finite mass m, moving in a one-dimensional viscous environment and biased by a spatially dependent force, is considered. We present a rigorous mapping of the Fokker-Planck equation, which determines evolution of the particle density in phase space, onto the spatial coordinate x. The result is th...
1204.1145v1
2012-04-20
A Reanalysis of the Hydrodynamic Theory of Fluid, Polar-Ordered Flocks
I reanalyze the hydrodynamic theory of fluid, polar ordered flocks. I find new linear terms in the hydrodynamic equations which slightly modify the anisotropy, but not the scaling, of the damping of sound modes. I also find that the nonlinearities allowed {\it in equilibrium} do not stabilize long ranged order in spati...
1204.4527v1
2012-04-26
Dynamics of a nano-scale rotor driven by single-electron tunneling
We investigate theoretically the dynamics and the charge transport properties of a rod-shaped nano-scale rotor, which is driven by a similar mechanism as the nanomechanical single-electron transistor (NEMSET). We show that a static electric potential gradient can lead to self-excitation of oscillatory or continuous rot...
1204.5918v1
2012-04-26
Avalanches in Strained Amorphous Solids: Does Inertia Destroy Critical Behavior?
Simulations are used to determine the effect of inertia on athermal shear of a two-dimensional binary Lennard-Jones glass. In the quasistatic limit, shear occurs through a series of rapid avalanches. The distribution of avalanches is analyzed using finite-size scaling with thousands to millions of particles. Inertia ta...
1204.5965v1
2012-04-29
Coherent phonon dynamics at the martensitic phase transition of Ni_2MnGa
We use time-resolved optical reflectivity to study the laser stimulated dynamics in the magnetic shape memory alloy Ni_2MnGa. We observe two coherent optical phonons, at 1.2 THz in the martensite phase and at 0.7 THz in the pre-martensite phase, which we interpret as a zone-folded acoustic phonon and a heavily damped a...
1204.6463v1
2012-05-01
Entangling homogeneously broadened matter qubits in the weak-coupling cavity-QED regime
In distributed quantum information processing, flying photons entangle matter qubits confined in cavities. However, when a matter qubit is homogeneously broadened, the strong-coupling regime of cavity QED is typically required, which is hard to realize in actual experimental setups. Here, we show that a high-fidelity e...
1205.0060v1
2012-05-04
State-independent teleportation of an atomic state between two cavities
A scheme is presented for the teleportation of an unknown atomic state between two separated cavities. The scheme involves two interaction-detection cycles and uses resonantly coupled atoms with an additional ground state not coupled to the cavity field. Remarkably, the damping of one basis state is balanced by that of...
1205.0981v1
2012-05-07
Spin and charge transport in material with spin-dependent conductivity
The spin and charge transport in materials with spin-dependent conductivity has been studied. It was shown that there is a charge accumulation along spin diffusion in a ferromagnetic metal, which causes a shortening of the spin diffusion length. It was shown that there is a substantial interaction between the drift and...
1205.1278v1
2012-05-24
SASE FEL Storage Ring
We explore the possibility of operating a SASE FEL with a Storage Ring. We use a semi-analytical model to obtain the evolution inside the undulator by taking into account the interplay on the laser dynamics due to the induced energy spread and to the radiation damping. We obtain the Renieri's limit for the stationary o...
1205.5445v1
2012-05-27
Effective dynamics of stochastic wave equation with a random dynamical boundary condition
This work is devoted to the effective macroscopic dynamics of a weakly damped stochastic nonlinear wave equation with a random dynamical boundary condition. The white noises are taken into account not only in the model equation defined on a domain perforated with small holes, but also in the dynamical boundary conditio...
1205.5948v1
2012-05-29
Predecoherence: before Decoherence and Collapse
Predecoherence, as its name indicates, is the same physical effect as decoherence, originating in the same interactions with an environment, injecting also incoherence and breaking unitarity. But whereas decoherence acts immediately after a measurement, predecoherence is acting long before. It is also a very strong eff...
1205.6390v1
2012-05-29
An iterative domain decomposition method for free boundary problems with nonlinear flux jump constraint
In this paper we design an iterative domain decomposition method for free boundary problems with nonlinear flux jump condition. Our approach is related to damped Newton's methods. The proposed scheme requires, in each iteration, the approximation of the flux on (both sides of) the free interface. We present a Finite El...
1205.6429v1
2012-05-30
Defeating entanglement sudden death by a single local filtering
Genuine multipartite entanglement of a quantum system can be partially destroyed by local decoherence. Is it possible to retrieve the entanglement to some extent by a single local operation? The answer to this question depends very much on the type of initial genuine entanglement. For initially pure W and cluster state...
1205.6601v1
2012-06-22
Finite-size scaling in the quantum phase transition of the open-system Dicke-model
Laser-driven Bose-Einstein condensate of ultracold atoms loaded into a lossy high-finesse optical resonator exhibits critical behavior and, in the thermodynamic limit, a phase transition between stationary states of different symmetries. The system realizes an open-system variant of the celebrated Dicke-model. We study...
1206.5131v1
2012-06-27
Domain wall propagation through spin wave emission
We theoretically study field-induced domain wall (DW) motion in an electrically insulating ferromagnet with hard- and easy-axis anisotropies. DWs can propagate along a dissipationless wire through spin wave emission locked into the known soliton velocity at low fields. In the presence of damping, the mode appears befor...
1206.6244v1
2012-07-10
The missing asymptotic sector of rotating black-hole spectroscopy
The rotation of a black hole splits its spectrum in two, yet only one sector is known in the highly-damped regime. We find the second, at least partly oblate sector, with quasinormal modes approaching the total reflection frequencies \omega(n>>1) ~ m\Omega - 2\pi iT(n-s), where \Omega and T are the horizon angular velo...
1207.2460v1
2012-07-22
Asymptotic dynamics of the alternate degrees of freedom for a two-mode system: an analytically solvable model
The composite systems can be non-uniquely decomposed into parts (subsystems). Not all decompositions (structures) of a composite system are equally physically relevant. In this paper we answer on theoretical ground why it may be so. We consider a pair of mutually un-coupled modes in the phase space representation that ...
1207.5260v1
2012-07-24
Van Kampen modes for bunch longitudinal motion
Conditions for existence, uniqueness and stability of bunch steady states are considered. For the existence uniqueness problem, simple algebraic equations are derived, showing the result both for the action and Hamiltonian domain distributions. For the stability problem, van Kampen theory is used. Emerging of discrete ...
1207.5826v1
2012-07-30
A Nonlinear Dynamics Characterization of The Scrape-off Layer Plasma Fluctuations
A stochastic differential equation for the plasma density dynamics is derived, consistent with the experimentally measured distribution and the theoretical quadratic nonlinearity. The plasma density is driven by a multiplicative Wiener process and evolves on the turbulence correlation time scale, while the linear growt...
1207.6981v2
2012-08-03
Scaling of the Rényi entropies in gapped quantum spin systems: Entanglement-driven order beyond symmetry breaking
We investigate the scaling of the R\'enyi $\alpha$-entropies in one-dimensional gapped quantum spin models. We show that the block entropies with $\alpha > 2$ violate the area law monotonicity and exhibit damped oscillations. Depending on the existence of a factorized ground state, the oscillatory behavior occurs eithe...
1208.0735v1
2012-09-01
Radiative energy loss of relativistic charged particles in absorptive media
We determine the energy loss spectrum per time-interval of a relativistic charge traversing a dispersive medium. Polarization and absorption effects in the medium are modelled via a complex index of refraction. We find that the spectrum amplitude becomes exponentially damped due to absorption mechanisms. Taking explici...
1209.0077v1
2012-09-01
Approximation of the random inertial manifold of singularly perturbed stochastic wave equations
By applying Rohlin's result on the classification of homomorphisms of Lebesgue space, the random inertial manifold of a stochastic damped nonlinear wave equations with singular perturbation is proved to be approximated almost surely by that of a stochastic nonlinear heat equation which is driven by a new Wiener process...
1209.0090v1
2012-09-03
Focusing in Multiwell Potentials: Applications to Ion Channels
We investigate out of equilibrium stationary distributions induced by a stochastic dichotomous noise on double and multi-well models for ion channels. Ion-channel dynamics is analyzed both through over-damped Langevin equations and master equations. As a consequence of the external stochastic noise, we prove a non triv...
1209.0505v2
2012-09-05
Dynamical excitations in the collision of 2D Bose-Einstein condensates
We carry out simulations of the collision of two components of an adiabatically divided, quasi-2D BEC. We identify under, over and critically damped regimes in the dipole oscillations of the components according to the balance of internal and centre-of-mass (c.m.) energies of the components and investigate the creation...
1209.0840v2
2012-09-10
Trajectory trapping and the evolution of drift turbulence beyond the quasilinear stage
Test modes on turbulent magnetized plasmas are studied taking into account the ion trapping that characterizes the E x B drift in the background turbulence. We show that trappyng provides the physical mechanism for the formation of large scale potential structures (inverse cascade) observed in drift turbulence. Trappin...
1209.2083v1
2012-09-14
Skyrmion Dynamics in Multiferroic Insulator
Recent discovery of Skyrmion crystal phase in insulating multiferroic compound Cu$_2$OSeO$_3$ calls for new ways and ideas to manipulate the Skyrmions in the absence of spin transfer torque from the conduction electrons. It is shown here that the position-dependent electric field, pointed along the direction of the ave...
1209.3120v1
2012-09-15
Cavity Optomechanics with a Bose-Einstein Condensate: Normal Mode Splitting
We study the normal mode splitting in a system consisting of a Bose Einstein condensates (BECs) trapped inside a Fabry Perot cavity driven by a single mode laser field. We analyze the variations in frequency and damping rate of the collective density excitation of a BEC imparted by the optical field. We study the occur...
1209.3354v1
2012-09-19
Entropy evolution law in a laser process
For the first time, we obtain the entropy variation law in a laser process after finding the Kraus operator of the master equation describing the laser process with the use of the entangled state representation. The behavior of entropy is determined by the competition of the gain and damping in the laser process. The p...
1209.4149v2
2012-09-26
Impact of r-modes on the cooling of neutron stars
Studying the frequency and temperature evolution of a compact star can give us valuable information about the microscopic properties of the matter inside the star. In this paper we study the effect of dissipative reheating of a neutron star due to r-mode oscillations on its temperature evolution. We find that there is ...
1209.5962v1
2012-10-10
Dissipation-Assisted Quantum Information Processing with Trapped Ions
We introduce a scheme to perform dissipation-assisted quantum information processing in ion traps considering realistic decoherence rates, for example, due to motional heating. By means of continuous sympathetic cooling, we overcome the trap heating, and show that the damped vibrational excitations can still be exploit...
1210.2860v3
2012-10-12
Bulk-like viscosity and shear thinning during dynamic compression of a nanoconfined liquid
The viscosity of liquids under nanoconfinement remains controversial. Reports range from spontaneous solidification to no change in the viscosity at all. Here, we present thorough measurements with a small-amplitude linear atomic force microscopy technique and careful consideration of the confinement geometry, to show ...
1210.3540v1
2012-10-14
Quasinormal frequencies using the hidden conformal symmetry of the Schwarzschild black hole
We show that the hidden conformal symmetry of the Schwarzschild black hole is realized from the AdS$_2$ sector of the AdS$_2\times S^2$, but not from the Rindler spacetime which is the genuine near-horizon geometry of the Schwarzschild black hole. This implies that purely imaginary quasinormal frequencies obtained usin...
1210.3760v2
2012-10-18
Giant dipole resonance in $^{201}$Tl at low temperature
The thermal pairing gap obtained by embedding the exact solutions of the pairing problem into the canonical ensemble is employed to calculate the width and strength function of the giant dipole resonance (GDR) within the phonon damping model. The results of calculations describe reasonably well the data for the GDR wid...
1210.5011v1
2012-10-19
A kinetic model of radiating electrons
A kinetic theory is developed to describe radiating electrons whose motion is governed by the Lorentz-Dirac equation. This gives rise to a generalized Vlasov equation coupled to an equation for the evolution of the physical submanifold of phase space. The pathological solutions of the 1-particle theory may be removed b...
1210.5467v1
2012-10-22
Excitations in a quantum spin liquid with random bonds
We present results of inelastic neutron scattering study on two bond disordered quasi twodimensional quantum magnets (C$_4$H$_12$N$_2$)Cu$_2$(Cl$_{1-x}$Br$_x$)$_6$ with x=0.035 and 0.075. We observe the increase of spin gap, reduction of magnon bandwidth and a decrease of magnon lifetimes compared to x=0 sample. Additi...
1210.5899v1
2012-10-23
Solution of electric-field-driven tight-binding lattice in contact with fermion reservoir
Electrons in tight-binding lattice driven by DC electric field dissipate their energy through on-site fermionic thermostats. Due to the translational invariance in the transport direction, the problem can be block-diagonalized. We solve this time-dependent quadratic problem and demonstrate that the problem has an oscil...
1210.6297v2
2012-10-27
Magnet traveling through a conducting pipe: a variation on the analytical approach
We present an analytical study of magnetic damping. In particular, we investigate the dynamics of a cylindrical neodymium magnet as it moves through a conducting tube. Owing to the very high degree of uniformity of the magnetization for neodymium magnets, we are able to provide completely analytical results for the EMF...
1210.7796v1
2012-11-01
Quantum and classical dissipation of charged particles
A Hamiltonian approach is presented to study the two dimensional motion of damped electric charges in time dependent electromagnetic fields. The classical and the corresponding quantum mechanical problems are solved for particular cases using canonical transformations applied to Hamiltonians for a particle with variabl...
1211.0067v2
2012-11-01
Oscillatory dynamics and non-markovian memory in dissipative quantum systems
The nonequilibrium dynamics of a small quantum system coupled to a dissipative environment is studied. We show that (1) the oscillatory dynamics close to a coherent-to-incoherent transition is surprisingly different from the one of the classical damped harmonic oscillator and that (2) non-markovian memory plays a promi...
1211.0293v3
2012-11-12
Spinning dust radiation: a review of the theory
This article reviews the current status of theoretical modeling of electric dipole radiation from spinning dust grains. The fundamentally simple problem of dust grain rotation appeals to a rich set of concepts of classical and quantum physics, owing the the diversity of processes involved. Rotational excitation and dam...
1211.2748v1
2012-11-15
Voltage-controlled surface plasmon-polaritons in double graphene layer structures
We study the spectra and damping of surface plasmon-polaritons in double graphene layer structures. It is shown that application of bias voltage between layers shifts the edge of plasmon absorption associated with the interband transitions. This effect could be used in efficient plasmonic modulators. We reveal the infl...
1211.3629v2
2012-11-25
Realignment Entanglement Criterion for Continuous Bipartite Symmetric Quantum States
The separability of bipartite non-Gaussian states is studied by applying the realignment criterion with the technique of functional analysis. The realignment criterion is given as one inequality in contrast to the infinitive number of inequalities based on the moments. We give the necessary and sufficient condition of ...
1211.5725v2
2012-12-07
Well-posedness and stabilization of a model system for long waves posed on a quarter plane
In this paper we are concerned with a initial boundary-value problem for a coupled system of two KdV equations, posed on the positive half line, under the effect of a localized damping term. The model arises when modeling the propagation of long waves generated by a wave maker in a channel. It is shown that the solutio...
1212.1602v1
2012-12-07
Molecular Dynamics and OKMC Study of Radiation Induced Motion of Voids and He Bubbles in BCC Iron
We show that voids adjacent to radiation damage cascades can be moved in their entirety by several lattice spacings. This is done using molecular dynamics cascade simulations in iron at energies of 1-5 keV. The effect of this mechanism is studied further using an OKMC code and shows enhancement of void diffusion by 2 o...
1212.1652v2
2012-12-17
Soft Mode in cubic PbTiO3 by Hyper-Raman Scattering
Hyper-Raman scattering experiments allowed collecting the spectra of the lowest F1u-symmetry mode of PbTiO3 crystal in the paraelectric phase up to 930K as well as down to about 1K above the phase transition. It is realized that this mode is fully responsible for the Curie-Weiss behavior of its dielectric permittivity ...
1212.3982v1
2012-12-26
Entropy production in open quantum systems: exactly solvable qubit models
We present analytical results for the time-dependent information entropy in exactly solvable two-state (qubit) models. The first model describes dephasing (decoherence) in a qubit coupled to a bath of harmonic oscillators. The entropy production for this model in the regimes of "complete" and "incomplete" decoherence i...
1212.6135v1
2012-12-12
Expectation Propogation for approximate inference in dynamic Bayesian networks
We describe expectation propagation for approximate inference in dynamic Bayesian networks as a natural extension of Pearl s exact belief propagation.Expectation propagation IS a greedy algorithm, converges IN many practical cases, but NOT always.We derive a DOUBLE - loop algorithm, guaranteed TO converge TO a local mi...
1301.0572v1
2013-01-09
Spectral function of the Bloch-Nordsieck model at finite temperature
In this paper we determine the exact fermionic spectral function of the Bloch-Nordsieck model at finite temperature. Analytic results are presented for some special parameters, for other values we have numerical results. The spectral function is finite and normalizable for any nonzero temperature values. The real time ...
1301.1803v1
2013-01-09
Quantum Refrigerator
We consider fault-tolerant quantum computation in the context where there are no fresh ancilla qubits available during the computation, and where the noise is due to a general quantum channel. We show that there are three classes of noisy channels: In the first, typified by the depolarizing channel, computation is only...
1301.1995v1
2013-01-14
Direct transition from quantum escape to phase diffusion regime in YBaCuO biepitaxial Josephson Junctions
Dissipation encodes interaction of a quantum system with the environment and regulates the activation regimes of a Brownian particle. We have engineered grain boundary biepitaxial YBaCuO junctions to drive a direct transition from quantum activated running state to phase diffusion regime. The cross-over to the quantum ...
1301.3162v1
2013-01-18
Nonlinear dynamical systems and linearly forced isotropic turbulence
In this paper, we present an extensive study of linearly forced isotropic turbulence. By using an analytical method, we identified two parametric choices that are new to our knowledge. We proved that the underlying nonlinear dynamical system for linearly forced isotropic turbulence is the general case of a cubic Lienar...
1301.4383v2
2013-01-28
Comparison of f-Q scaling in wineglass and radial modes in ring resonators
Low phase noise MEMS oscillators necessitate resonators with high f-Q. Resonators achieving high f-Q (mechanical frequency-quality factor product) close to the thermo-elastic damping (TED) limit have been demonstrated at expense of feed-through. Here we present a study comparing frequency scaling of quality factors of ...
1301.6564v1
2013-02-08
Comparison of quantum and classical relaxation in spin dynamics
The classical Landau-Lifshitz equation with damping term has been derived from the time evolution of a quantum mechanical wave function under the assumption of a non-hermitian Hamilton operator. Further, the trajectory of a classical spin $\mathrm{S}$ has been compared with the expectation value of the spin operator $\...
1302.1985v1
2013-02-20
Convergence to Gibbs equilibrium - unveiling the mystery
We consider general hamiltonian systems with quadratic interaction potential and $N<\infty$ degrees of freedom, only $m$ of which have contact with external world, that is subjected to damping and random stationary external forces. We show that, as $t\to\infty$, already for $m=1$, the unique limiting distribution exist...
1302.4832v2
2013-02-20
Doping Induced Spin State Transition in LaCoO3: Dynamical Mean-Field Study
Hole and electron doped LaCoO3 is studied using dynamical mean-field theory. The one-particle spectra are analyzed and compared to the available experimental data, in particular the x-ray absorption spectra. Analyzing the temporal spin-spin correlation functions we find the atomic intermediate spin state is not importa...
1302.4925v2
2013-02-20
Quantum speed limit for non-Markovian dynamics
We derive a Margolus-Levitin type bound on the minimal evolution time of an arbitrarily driven open quantum system. We express this quantum speed limit time in terms of the operator norm of the nonunitary generator of the dynamics. We apply these results to the damped Jaynes-Cummings model and demonstrate that the corr...
1302.5069v2
2013-02-21
Flow Vorticity in Peripheral High Energy Heavy Ion Collisions
The vorticity development is studied in the reaction plane of peripheral relativistic heavy ion reactions where the initial state has substantial angular momentum. The earlier predicted rotation effect and Kelvin Helmholtz Instability, lead to significant initial vorticity and circulation. In low viscosity QGP this vor...
1302.5310v1
2013-02-21
Gravity-related wave function collapse: Is superfluid He exceptional?
The gravity-related model of spontaneous wave function collapse, a longtime hypothesis, damps the massive Schr\"odinger Cat states in quantum theory. We extend the hypothesis and assume that spontaneous wave function collapses are responsible for the emergence of Newton interaction. Superfluid helium would then show si...
1302.5364v1
2013-02-28
Deterministic macroscopic quantum superpositions of motion via quadratic optomechanical coupling
We propose a scheme to prepare macroscopic quantum superpositions of motion in optomachanical nano- or micromechanical oscillators quadratically coupled to an intracavity field. The nonlinear optomechanical coupling leads to an effective degenerate three-wave mixing interaction between the mechanical and cavity modes. ...
1302.7087v1
2013-03-06
Beam loading
We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compens...
1303.1358v1
2013-03-18
On decay and blow-up of solutions for a singular nonlocal viscoelastic problem with a nonlinear source term
In this paper we consider a singular nonlocal viscoelastic problem with a nonlinear source term and a possible damping term. We proved that if the initial data enter into the stable set, the solution exists globally and decays to zero with a more general rate, and if the initial data enter into the unstable set, the so...
1303.4246v1
2013-03-19
Complexity and simplicity of plasmas
This paper has two main parts. The first one presents a direct path from microscopic dynamics to Debye screening, Landau damping and collisional transport. It shows there is more simplicity in microscopic plasma physics than previously thought. The second part is more subjective. It describes some difficulties in facin...
1303.4613v2