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2023-08-02
Blow-up and lifespan estimate for the generalized tricomi equation with the scale-invariant damping and time derivative nonlinearity on exterior domain
The article is devoted to investigating the initial boundary value problem for the damped wave equation in the scale-invariant case with time-dependent speed of propagation on the exterior domain. By presenting suitable multipliers and applying the test-function technique, we study the blow-up and the lifespan of the s...
2308.01272v2
2023-08-03
Gravitational Wave Heating
It was shown in previous work that when a gravitational wave (GW) passes through a viscous shell of matter the magnitude of the GW will be damped and there are astrohysical circumstances in which the damping is almost complete. The energy transfer from the GWs to the fluid will increase its temperature. We construct a ...
2308.01615v2
2023-08-08
Stabilization of piezoelectric beam with Coleman-Gurtin or Gurtin-Pipkin thermal law and under Lorenz gauge condition
In this paper, we present the analysis of stability for a piezoelectric beam subject to a thermal law (Coleman-Gurtin or Gurtin-Pipkin thermal law) adding some viscous damping mechanism to the electric field in $x-$direction and $z-$direction, and we discuss several cases. Then, there is no need to control the electric...
2308.04231v2
2023-08-11
Well-posedness and global attractor for wave equation with nonlinear damping and super-cubic nonlinearity
In the paper, we study the semilinear wave equation involving the nonlinear damping $g(u_t) $ and nonlinearity $f(u)$. Under the wider ranges of exponents of $g$ and $f$, the well-posedness of the weak solution is achieved by establishing a priori space-time estimates. Then, the existence of the global attractor in the...
2308.06208v1
2023-08-16
Stability for degenerate wave equations with drift under simultaneous degenerate damping
In this paper we study the stability of two different problems. The first one is a one-dimensional degenerate wave equation with degenerate damping, incorporating a drift term and a leading operator in non-divergence form. In the second problem we consider a system that couples degenerate and non-degenerate wave equati...
2308.08645v3
2023-09-02
Existence and nonexistence of global solutions for time-dependent damped NLS equations
We investigate the Cauchy problem for the nonlinear Schr\"odinger equation with a time-dependent linear damping term. Under non standard assumptions on the loss dissipation, we prove the blow-up in the inter-critical regime, and the global existence in the energy subcritical case. Our results generalize and improve the...
2309.00849v1
2023-09-04
On the small-mass limit for stationary solutions of stochastic wave equations with state dependent friction
We investigate the convergence, in the small mass limit, of the stationary solutions of a class of stochastic damped wave equations, where the friction coefficient depends on the state and the noisy perturbation if of multiplicative type. We show that the Smoluchowski-Kramers approximation that has been previously show...
2309.01549v1
2023-09-09
Finite-dimensionality of attractors for wave equations with degenerate nonlocal damping
In this paper we study the fractal dimension of global attractors for a class of wave equations with (single-point) degenerate nonlocal damping. Both the equation and its linearization degenerate into linear wave equations at the degenerate point and the usual approaches to bound the dimension of the entirety of attrac...
2309.04712v2
2023-09-19
The Raman gap and collisional absorption
One of the long-standing puzzles observed in many laser-plasma experiments is the gap in the Raman backscattering spectrum. This gap is characterized by the absence of backscattered light between some critical wavelength and twice the incident laser wavelength. The latter is associated with the absolute Raman instabili...
2309.10366v1
2023-09-21
Inverse problems for a quasilinear strongly damped wave equation arising in nonlinear acoustics
We consider inverse problems for a Westervelt equation with a strong damping and a time-dependent potential $q$. We first prove that all boundary measurements, including the initial data, final data, and the lateral boundary measurements, uniquely determine $q$ and the nonlinear coefficient $\beta$. The proof is based ...
2309.11775v1
2023-09-28
On inverse problems for a strongly damped wave equation on compact manifolds
We consider a strongly damped wave equation on compact manifolds, both with and without boundaries, and formulate the corresponding inverse problems. For closed manifolds, we prove that the metric can be uniquely determined, up to an isometry, from the knowledge of the source-to-solution map. Similarly, for manifolds w...
2309.16182v1
2023-10-10
Emerging Spin-Orbit Torques in Low Dimensional Dirac Materials
We report a theoretical description of novel spin-orbit torque components emerging in two-dimensional Dirac materials with broken inversion symmetry. In contrast to usual metallic interfaces where field-like and damping-like torque components are competing, we find that an intrinsic damping-like torque which derives fr...
2310.06447v1
2023-10-22
The residual flow in well-optimized stellarators
The gyrokinetic theory of the residual flow, in the electrostatic limit, is revisited, with optimized stellarators in mind. We consider general initial conditions for the problem, and identify cases that lead to a non-zonal residual electrostatic potential, i.e. one having a significant component that varies within a f...
2310.14218v1
2023-10-26
Efficient Numerical Algorithm for Large-Scale Damped Natural Gradient Descent
We propose a new algorithm for efficiently solving the damped Fisher matrix in large-scale scenarios where the number of parameters significantly exceeds the number of available samples. This problem is fundamental for natural gradient descent and stochastic reconfiguration. Our algorithm is based on Cholesky decomposi...
2310.17556v1
2023-11-09
Exponential convergence to steady-states for trajectories of a damped dynamical system modelling adhesive strings
We study the global well-posedness and asymptotic behavior for a semilinear damped wave equation with Neumann boundary conditions, modelling a one-dimensional linearly elastic body interacting with a rigid substrate through an adhesive material. The key feature of of the problem is that the interplay between the nonlin...
2311.05295v1
2023-11-29
On the exponential stability of uniformly damped wave equations
We study damped wave propagation problems phrased as abstract evolution equations in Hilbert spaces. Under some general assumptions, including a natural compatibility condition for initial values, we establish exponential decay estimates for all mild solutions using the language and tools of Hilbert complexes. This fra...
2311.18084v1
2023-12-01
Semilinear wave inequalities with double damping and potential terms on Riemannian Manifolds
We study a semilinear wave inequality with double damping on a complete noncompact Riemannian manifold. The considered problem involves a potential function $V$ depending on the space variable in front of the power nonlinearity and an inhomogeneous term $W$ depending on both time and space variables. Namely, we establi...
2312.00617v1
2023-12-29
On damping a control system of arbitrary order with global aftereffect on a tree
We study a problem of damping a control system described by functional-differential equations of natural order $n$ and neutral type with non-smooth complex coefficients on an arbitrary tree with global delay. The latter means that the delay propagates through internal vertices of the tree. Minimization of the energy fu...
2312.17592v1
2024-01-11
Weak collision effect on nonlinear Landau damping for the Vlasov-Poisson-Fokker-Planck system
We investigate the impact of weak collisions on Landau damping in the Vlasov-Poisson-Fokker-Planck system on a torus, specifically focusing on its proximity to a Maxwellian distribution. In the case where the Gevrey index satisfies $\frac{1}{s}<3$, we establish the global stability and enhanced dissipation of small ini...
2401.05601v3
2024-01-23
Revisit on global existence of solutions for semilinear damped wave equations in $\mathbb{R}^N$ with noncompactly supported initial data
In this note, we study the Cauchy problem of the semilinear damped wave equation and our aim is the small data global existence for noncompactly supported initial data. For this problem, Ikehata and Tanizawa [5] introduced the energy method with the exponential-type weight function $e^{|x|^2/(1+t)}$, which is the so-ca...
2401.12530v1
2024-01-24
Eigenmode analysis of the damped Jaynes-Cummings model
The generating functions for density matrix elements of the Jaynes-Cummings model with cavity damping are analysed in terms of their eigenmodes, which are characterised by a specific temporal behaviour. These eigenmodes are shown to be proportional to particular generalised hypergeometric functions. The relative weight...
2401.13348v1
2024-02-15
A comprehensive modelling and experimental approach for damped oscillations in U-tubes via Easy JavaScript Simulations
In recent years, science simulations have become popular among educators due to their educational usefulness, availability, and potential for increasing the students' knowledge on scientific topics. In this paper, we introduce the implementation of a user-friendly simulation based on Easy Java/JavaScript Simulations (E...
2402.09866v1
2024-02-21
Hybrid Multi-Directional Quantum Communication Protocol
The way a new type of state called a hybrid state, which contains more than one degree of freedom, is used in many practical applications of quantum communication tasks with lesser amount of resources. Similarly, our aim is here to perform multi-quantum communication tasks in a protocol to approach quantum information ...
2402.14043v1
2024-03-19
Damped energy-norm a posteriori error estimates for fully discrete approximations of the wave equation using C2-reconstructions
We derive a posteriori error estimates for the the scalar wave equation discretized in space by continuous finite elements and in time by the explicit leapfrog scheme. Our analysis combines the idea of invoking extra time-regularity for the right-hand side, as previously introduced in the space semi-discrete setting, w...
2403.12954v1
1995-02-09
A linear thermohaline oscillator driven by stochastic atmospheric forcing
The interdecadal variability of a stochastically forced four-box model of the oceanic meridional thermohaline circulation (THC) is described and compared to the THC variability in the coupled ocean-atmosphere GCM of Delworth, Manabe, and Stouffer (1993). The box model is placed in a linearly stable thermally dominant m...
9502002v2
1993-09-30
The metal systems in Q0000--2619 at high resolution
We have obtained high, 11 and 14 \kms, and medium, 40 and 53 \kms, resolution spectra of the $z_{em} = 4.11$ quasar Q0000--2619 covering the range 4400 \AA\ to 9265 \AA . We identify nine metal absorption systems, of which four were previously known. A fifth previously suggested system at $z_{abs} \approx 3.409$ (Turns...
9309053v1
1994-12-27
The z=0.8596 Damped Lyman Alpha Absorbing Galaxy Toward PKS 0454+039
We present {\it Hubble Space Telescope} and ground--based data on the $z_{abs}=0.8596$ metal line absorption system along the line of sight to PKS 0454+0356. The system is a moderate redshift damped Lyman alpha system, with ${\rm N(HI)}=(5.7\pm0.3)\times10^{20}$~cm$^{-2}$ as measured from the {\it Faint Object Spectrog...
9412093v2
1995-05-17
GRAVITATIONAL LENSING OF QUASARS BY THEIR DAMPED LYMAN-ALPHA ABSORBERS
Damped Lyman-alpha absorbers are believed to be associated with galactic disks. We show that gravitational lensing can therefore affect the statistics of these systems. First, the magnification bias due to lensing raises faint QSOs above a given magnitude threshold and thereby enhances the probability for observing dam...
9505078v1
1996-08-22
APM z>4 QSO Survey: Distribution and Evolution of High Column Density HI Absorbers
Eleven candidate damped Lya absorption systems were identified in 27 spectra of the quasars from the APM z>4 survey covering the redshift range 2.8<z(abs)<4.4 (8 with z(abs)>3.5). High resolution echelle spectra (0.8A FWHM) have been obtained for three quasars, including 2 of the highest redshift objects in the survey....
9608146v1
1997-05-16
Testing Cosmological Models Against the Abundance of Damped Lyman-Alpha Absorbers
We calculate the number of damped Lyman-alpha absorbers expected in various popular cosmological models as a function of redshift and compare our predictions with observed abundances. The Press-Schechter formalism is used to obtain the distribution of halos with circular velocity in different cosmologies, and we calibr...
9705118v1
1997-05-28
Zinc and Chromium Abundances in a Third Damped Lyman alpha System at Intermediate Redshift
We have determined the metallicity of the $z_{abs} = 1.0093$ damped Lyman alpha system in the bright QSO EX 0302-223; this is only the third such measurement at redshifts $z \simlt 1$. Unlike the previous two cases, we find that the abundance of Zn is only a factor of $\sim 2$ lower than in the Galactic interstellar me...
9705222v1
1998-11-18
The Closest Damped Lyman Alpha System
A difficulty of studying damped Lyman alpha systems is that they are distant, so one knows little about the interstellar medium of the galaxy. Here we report upon a damped Lyman alpha system in the nearby galaxy NGC 4203, which is so close (v_helio = 1117 km/s) and bright (B_o = 11.62) that its HI disk has been mapped....
9811274v1
1999-07-29
Ionized Gas in Damped Lyman-alpha Systems and Its Effects on Elemental Abundance Studies
Recent high-resolution observations of metal absorption lines in high-redshift damped Ly-alpha systems have shown that Al III, a tracer of moderately-ionized gas, very often has a velocity structure indistinguishable from that of low-ionization gas. Regions of ionized and neutral hydrogen in these systems are likely co...
9907428v1
1999-11-09
Detection of Warm and Cold Phases of the Neutral ISM in a Damped Ly-alpha Absorber
We present a detailed study of the HI 21cm absorption system at z=0.0912 towards the radio quasar B0738+313. The uncommonly narrow main absorption line and weak secondary line are resolved for the first time. In addition we find it necessary to add a third, broader shallow component to obtain a good fit to the spectrum...
9911142v1
2000-06-01
Crust-core coupling and r-mode damping in neutron stars: a toy model
R-modes in neutron stars with crusts are damped by viscous friction at the crust-core boundary. The magnitude of this damping, evaluated by Bildsten and Ushomirsky (BU) under the assumption of a perfectly rigid crust, sets the maximum spin frequency for a neutron star spun up by accretion in a Low-Mass X-ray binary (LM...
0006028v1
2001-03-23
First Investigation of the Clustering Environment of Damped Lyman Alpha Absorbers at z=4
We report the first observations of the clustering environment of damped Lyman alpha absorption systems at z=4. Color selection and photometric redshifts were used to select 44 candidate Lyman-break galaxies brighter than I_AB=25.5 from deep BRI images of the 35 sq. arcmin field containing the quasar BR 0951-04. Multis...
0103387v2
2002-11-11
Damped Lyman alpha systems and galaxy formation models - II. High ions and Lyman limit systems
We investigate a model for the high-ionization state gas associated with observed damped Lyman-alpha systems, based on a semi-analytic model of galaxy formation set within the paradigm of hierarchical structure formation. In our model, the hot gas in halos and sub-halos gives rise to CIV absorption, while the low-ioniz...
0211231v1
2003-05-16
The Age-Metallicity Relation of the Universe in Neutral Gas: The First 100 Damped Lya Systems
We present accurate metallicity measurements for 121 damped Lya systems at 0.5<z<5 including ~50 new measurements from our recently published Echellette Spectrograph and Imager surveys. This dataset is analysed to determine the age-metallicity relation of neutral gas in the universe. Contrary to previous datasets this ...
0305314v1
2003-09-24
WIMP matter power spectra and small scale power generation
Dark Matter (DM) is generally assumed to be massive, cold and collisionless from the structure formation point of view. A more correct statement however is that DM indeed experiences collisional damping, but on a scale which is supposed to be too small to be relevant for structure formation. The aim of this paper is to...
0309652v1
2004-03-16
The SDSS Damped Lya Survey: Data Release 1
We present the results from an automated search for damped Lya (DLA) systems in the quasar spectra of Data Release 1 from the Sloan Digital Sky Survey (SDSS-DR1). At z~2.5, this homogeneous dataset has greater statistical significance than the previous two decades of research. We derive a statistical sample of 71 dampe...
0403391v2
2006-06-28
Neutral gas density in Damped Lyman Alpha systems
We estimate the intrinsic neutral gas density in Damped Lyman Alpha systems ($\Omega_{HI}^{(DLA)}$) in the redshift range $ 2.2 \lesssim z \lesssim 5$ from the DLA SDSS DR_3 sample of optically selected quasars. We take into account self-consistently the obscuration on background quasars due to the dust present in Damp...
0606693v1
2006-09-06
Sun-as-a-star observations: evidence for degree dependence of changes in damping of low-l p modes along the solar cycle
We use 9.5-yr of BiSON Sun-as-a-star data to search for dependence of solar-cycle parameter changes on the angular degree, l, of the data. The nature of the Sun-as-a-star observations is such that for changes measured at fixed frequency, or for changes averaged across the same range in frequency, any l dependence prese...
0609156v2
1997-08-12
Coherence in the Quasi-Particle 'Scattering' by the Vortex Lattice in Pure Type-II Superconductors
The effect of quasi-particle (QP) 'scattering' by the vortex lattice on the de-Haas van-Alphen oscillations in a pure type-II superconductor is investigated within mean field,asymptotic perturbation theory. Using a 2D electron gas model it is shown that, due to a strict phase coherence in the many-particle correlation ...
9708088v1
1999-08-27
Electron Correlations in an Electron Bilayer at Finite Temperature: Landau Damping of the Acoustic Plasmon
We report angle-resolved Raman scattering observations of the temperature dependent Landau damping of the acoustic plasmon in an electron bilayer system realised in a GaAs double quantum well structure. Corresponding calculations of the charge-density excitation spectrum of the electron bilayer using forms of the rando...
9908408v1
2000-10-02
Comment on "Magnetic Breakdown at High Fields: Semiclassical and Quantum Treatments"
We comment on the study of the spin-damping factor on the de Haas-van Alphen (dHvA) discussed by Han et al. (Phys. Rev. Lett. 85, 1500 (2000)).
0010018v1
2002-03-11
Shubnikov - de Haas effect in the quantum vortex liquid state of the organic superconductor $κ$-(BEDT-TTF)$_{2}$Cu(NCS)$_{2}$
We report the Shubnikov-de Haas (SdH) oscillations observed in the vortex liquid state of the quasi two dimensional organic superconductor $\kappa$-(BEDT-TTF)$_{2}$Cu(NCS)$_{2}$. The SdH oscillations can be observed down to about 5 T at 0.5 K, where the flux flow resistivity becomes as small as about 30 % of the normal...
0203228v2
2003-03-13
Vibrational sidebands and dissipative tunneling in molecular transistors
Transport through molecular devices with strong coupling to a single vibrational mode is considered in the case where the vibration is damped by coupling to the environment. We focus on the weak tunneling limit, for which a rate equation approach is valid. The role of the environment can be characterized by a frictiona...
0303236v3
2004-09-03
Weyl equation for temperature fields induced by attosecond laser pulses
In this paper the Weyl equation for temperature field induced by laser beam interaction with matter is proposed and solved. Depending on the scattering mechanism the temperature field oscillate or is damped. Key words: Thermal processes, Weyl equation
0409076v1
2004-12-08
Spectroscopy of a driven solid-state qubit coupled to a structured environment
We study the asymptotic dynamics of a driven spin-boson system where the environment is formed by a broadened localized mode. Upon exploiting an exact mapping, an equivalent formulation of the problem in terms of a quantum two-state system (qubit) coupled to a harmonic oscillator which is itself Ohmically damped, is fo...
0412194v2
1995-03-08
A NEW NUMERICAL APPROACH TO THE OSCILLATION MODES OF RELATIVISTIC STARS
The oscillation modes of a simple polytropic stellar model are studied. Using a new numerical approach (based on integration for complex coordinates) to the problem for the stellar exterior we have computed the eigenfrequencies of the highly damped w-modes. The results obtained agree well with recent ones of Leins, Nol...
9503014v1
1998-01-29
On the gravitational, dilatonic and axionic radiative damping of cosmic strings
We study the radiation reaction on cosmic strings due to the emission of dilatonic, gravitational and axionic waves. After verifying the (on average) conservative nature of the time-symmetric self-interactions, we concentrate on the finite radiation damping force associated with the half-retarded minus half-advanced ``...
9801105v3
2004-10-15
A Nonlinear Coupling Network to Simulate the Development of the r-mode Instablility in Neutron Stars II. Dynamics
Two mechanisms for nonlinear mode saturation of the r-mode in neutron stars have been suggested: the parametric instability mechanism involving a small number of modes and the formation of a nearly continuous Kolmogorov-type cascade. Using a network of oscillators constructed from the eigenmodes of a perfect fluid inco...
0410072v1
1997-02-20
Numerical study of plasmon properties in the SU(2)-Higgs model
Using the (effective) classical approximation, we compute numerically time-dependent correlation functions in the SU(2)-Higgs model around the electroweak phase transition, for $m_H \approx m_W$. The parameters of the classical model have been determined previously by the dimensional reduction relations for time-indepe...
9702017v2
2001-01-16
Nonlinear Landau damping of a plasmino in the quark-gluon plasma
On the basis of the Blaizot-Iancu equations, which are a local formulation of the hard thermal loop (HTL) equations of motion for soft fluctuating quark and gluon fields and their induced sources, the coupled kinetic equations for plasminos and plasmons are obtained. The equality of matrix elements for nonlinear scatte...
0101167v2
2003-12-15
Nonequilibrium pion dynamics near the critical point in a constituent quark model
We study static and dynamical critical phenomena of chiral symmetry breaking in a two-flavor Nambu--Jona-Lasinio constituent quark model. We obtain the low-energy effective action for scalar and pseudoscalar degrees of freedom to lowest order in quark loops and to quadratic order in the meson fluctuations around the me...
0312185v2
2001-11-16
Resonances and superlattice pattern stabilization in two-frequency forced Faraday waves
We investigate the role weakly damped modes play in the selection of Faraday wave patterns forced with rationally-related frequency components m*omega and n*omega. We use symmetry considerations to argue for the special importance of the weakly damped modes oscillating with twice the frequency of the critical mode, and...
0111039v2
2002-02-01
Time Domain Computation of a Nonlinear Nonlocal Cochlear Model with Applications to Multitone Interaction in Hearing
A nonlinear nonlocal cochlear model of the transmission line type is studied in order to capture the multitone interactions and resulting tonal suppression effects. The model can serve as a module for voice signal processing, it is a one dimensional (in space) damped dispersive nonlinear PDE based on mechanics and phen...
0202004v3
2003-12-22
Intermittency is a consequence of turbulent transport in nonlinear systems
Intermittent high-amplitude structures emerge in a damped and driven discrete nonlinear Schroedinger equation whose solutions transport both energy and particles from sources to sinks. These coherent structures are necessary for any solution that has statistically stationary transport properties.
0312059v1
2004-06-17
Multi-frequency control of Faraday wave patterns
We show how pattern formation in Faraday waves may be manipulated by varying the harmonic content of the periodic forcing function. Our approach relies on the crucial influence of resonant triad interactions coupling pairs of critical standing wave modes with damped, spatio-temporally resonant modes. Under the assumpti...
0406034v1
1997-01-22
Shell Model for Warm Rotating Nuclei
In order to provide a microscopic description of levels and E2 transitions in rapidly rotating nuclei with internal excitation energy up to a few MeV, use is made of a shell model which combines the cranked Nilsson mean-field and the residual surface delta two-body force. The damping of collective rotational motion is ...
9701044v1
2005-04-21
Enhanced optical cooling of particle beams in storage rings
The problem of enhanced optical cooling (EOC) of particle beams in storage rings beyond the Robinson's damping criterion is discussed.
0504145v1
2005-10-21
Non-contact atomic force microscopy: Stability criterion and dynamical responses of the shift of frequency and damping signal
The aim of this article is to provide a complete analysis of the behavior of a noncontact atomic force microscope (NC-AFM). We start with a review of the equations of motion of a tip interacting with a surface in which the stability conditions are first revisited for tapping mode. Adding the equations of automatic gain...
0510192v1
1999-06-09
Quantum dynamics of a damped deformed oscillator
The interaction of a quantum deformed oscillator with the environment is studied deriving a master equation whose form strongly depends on the type of deformation.
9906031v1
2006-06-15
Purity and decoherence in the theory of a damped harmonic oscillator
For the generalized master equations derived by Karrlein and Grabert for the microscopic model of a damped harmonic oscillator, the conditions for purity of states are written, in particular for different initial conditions and different types of damping, including Ohmic, Drude and weak coupling cases, Agarwal and Weid...
0606134v1
2007-04-29
Long Term Evolution of Magnetic Turbulence in Relativistic Collisionless Shocks: Electron-Positron Plasmas
We study the long term evolution of magnetic fields generated by a collisionless relativistic $e^+e^-$ shock which is initially unmagnetized. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated shock, particle distributions are close to isotropic, relativistic Maxwellians, and t...
0704.3832v2
2007-06-21
Production of a sterile species via active-sterile mixing: an exactly solvable model
The production of a sterile species via active-sterile mixing in a thermal medium is studied in an exactly solvable model. The \emph{exact} time evolution of the sterile distribution function is determined by the dispersion relations and damping rates $\Gamma_{1,2}$ for the quasiparticle modes. These depend on $\wtg = ...
0706.3167v2
2007-08-02
Eccentricity evolution of giant planet orbits due to circumstellar disk torques
The extrasolar planets discovered to date possess unexpected orbital elements. Most orbit their host stars with larger eccentricities and smaller semi-major axes than similarly sized planets in our own solar system do. It is generally agreed that the interaction between giant planets and circumstellar disks (Type II mi...
0708.0335v1
2007-10-10
HE 0515-4414 - an unusual sub-damped Ly alpha system revisited
Using STIS and VLT UVES observations we have examined the ionization, abundances, and differential dust depletion of metals, the kinematic structure, and the physical conditions in the molecular hydrogen-bearing sub-damped Ly alpha system toward HE 0515-4414 at z = 1.15. The velocity interval of associated metal lines ...
0710.3560v1
2008-06-05
Viscous damping of r-mode oscillations in compact stars with quark matter
We determine characteristic timescales for the viscous damping of r-mode oscillations in rapidly rotating compact stars that contain quark matter. We present results for the color-flavor-locked (CFL) phase of dense quark matter, in which the up, down and strange quarks are gapped, as well as the normal (ungapped) quark...
0806.1005v2
2008-06-09
Relaxation Time and Relaxation Function of Quark-Gluon Plasma with Lattice QCD
We propose a method which enables a QCD-based calculation of a relaxation time for a dissipative current in the causal and dissipative hydrodynamic equation derived by Israel and Stewart. We point out that the Israel-Stewart equation is not unique as a causal and dissipative hydrodynamic equation, and the form of the c...
0806.1481v1
2008-06-18
Imaging method for interface rheological characterization
The present work investigates free damped oscillations of an oil drop in water after its release from a capillary tube. Both pure heptane drops and diluted crude oil drops are considered (in the second case the interface is covered by amphiphilic species, natural components of crude oil). Shadowgraph images of the drop...
0806.3030v1
2008-06-27
Klein - Gordon equation for market wealth operations
In this paper the modified Klein - Gordon equation for market processes is proposed and solved. It is argued that the oscillations in market propagate with the light velocity. The initial pulse in the market is damped and for very large time diffused according to the Fourier law.
0806.4466v1
2008-10-22
Mean Motion Resonances in Extrasolar Planetary Systems with Turbulence, Interactions, and Damping
This paper continues previous work on the effects of turbulence on mean motion resonances in extrasolar planetary systems. Turbulence is expected to arise in the disks that form planets, and these fluctuations act to compromise resonant configurations. This paper extends previous work by considering how interactions be...
0810.4076v1
2009-01-11
On the derivation of structural models with general thermomechanical prestress
The vibrating behaviour of thin structures is affected by prestress states. Hence, the effects of thermal prestress are important research subjects in view of ambient vibration monitoring of civil structures. The interaction between prestress, geometrically non-linear behaviour, as well as damping and its coupling with...
0901.1446v1
2009-04-17
On Landau damping
Going beyond the linearized study has been a longstanding problem in the theory of Landau damping. In this paper we establish exponential Landau damping in analytic regularity. The damping phenomenon is reinterpreted in terms of transfer of regularity between kinetic and spatial variables, rather than exchanges of ener...
0904.2760v5
2009-07-27
Parameter exploration of optically trapped liquid aerosols
When studying the motion of optically trapped particles on the $\mu s$ time scale, in low viscous media such as air, inertia cannot be neglected. Resolution of unusual and interesting behaviour not seen in colloidal trapping experiments is possible. In attempt to explain the phenomena we use power spectral methods to p...
0907.4582v2
2009-10-09
One-way coupled Van der Pol system
The equation of the Van der Pol oscillator, being characterized by a dissipative term, is non-Lagrangian. Appending an additional degree of freedom we bring the equation in the frame of action principle and thus introduce a one-way coupled system. As with the Van der Pol oscillator, the coupled system also involves onl...
0910.1700v1
2010-06-19
On the saturation amplitude of the f-mode instability
We investigate strong nonlinear damping effects which occur during high amplitude oscillations of neutron stars, and the gravitational waves they produce. For this, we use a general relativistic nonlinear hydrodynamics code in conjunction with a fixed spacetime (Cowling approximation) and a polytropic equation of state...
1006.3885v2
2010-07-06
Magneto-elastic oscillations and the damping of crustal shear modes in magnetars
In a realistic model of magneto-elastic oscillations in magnetars, we find that crustal shear oscillations, often invoked as an explanation of quasi-periodic oscillations (QPOs) seen after giant flares in soft gamma-ray repeaters (SGRs), are damped by resonant absorption on timescales of at most 0.2s, for a lower limit...
1007.0856v2
2010-08-16
Orbital evolution of eccentric planets in radiative discs
With an average eccentricity of about 0.29, the eccentricity distribution of extrasolar planets is markedly different from the solar system. Among other scenarios considered, it has been proposed that eccentricity may grow through planet-disc interaction. Recently, it has been noticed that the thermodynamical state of ...
1008.2656v1
2010-11-02
A Carbon-enhanced Metal-poor Damped Lyman alpha System: Probing Gas from Population III Nucleosynthesis?
We present high resolution observations of an extremely metal-poor damped Lyman-alpha system, at z_abs = 2.3400972 in the spectrum of the QSO J0035-0918, exhibiting an abundance pattern consistent with model predictions for the supernova yields of Population III stars. Specifically, this DLA has [Fe/H] = -3.04, shows a...
1011.0733v2
2010-11-08
Exponential stabilization without geometric control
We present examples of exponential stabilization for the damped wave equation on a compact manifold in situations where the geometric control condition is not satisfied. This follows from a dynamical argument involving a topological pressure on a suitable uncontrolled set.
1011.1699v1
2010-11-11
Damping of longitudinal magneto-acoustic oscillations in slowly varying coronal plasma
We investigate the propagation of MHD waves in a homogenous, magnetized plasma in a weakly stratified atmosphere, representing hot coronal loops. In most of earlier studies a time-independent equilibrium is considered. Here we abandon this restriction and allow the equilibrium to develop as function of time. In particu...
1011.2617v1
2010-12-17
Optimal switching of a nanomagnet assisted by microwaves
We develop an efficient and general method for optimizing the microwave field that achieves magnetization switching with a smaller static field. This method is based on optimal control and renders an exact solution for the 3D microwave field that triggers the switching of a nanomagnet with a given anisotropy and in an ...
1012.3901v1
2010-12-22
PageRank for ranking authors in co-citation networks
Google's PageRank has created a new synergy to information retrieval for a better ranking of Web pages. It ranks documents depending on the topology of the graphs and the weights of the nodes. PageRank has significantly advanced the field of information retrieval and keeps Google ahead of competitors in the search engi...
1012.4872v1
2011-01-20
Magnetohydrodynamic waves in solar partially ionized plasmas: two-fluid approach
We derive the dynamics of magnetohydrodynamic waves in two-fluid partially ionized plasmas and to compare the results with those obtained under single-fluid description. Two-fluid magnetohydrodynamic equations are used, where ion-electron plasma and neutral particles are considered as separate fluids. Dispersion relati...
1101.3913v1
2011-08-25
Characterizing Multi-planet Systems with Classical Secular Theory
Classical secular theory can be a powerful tool to describe the qualitative character of multi-planet systems and offer insight into their histories. The eigenmodes of the secular behavior, rather than current orbital elements, can help identify tidal effects, early planet-planet scattering, and dynamical coupling amon...
1108.5149v2
2011-09-12
Nonlinear spectroscopy of superconducting anharmonic resonators
We formulate a model for the steady state response of a nonlinear quantum oscillator structure, such as those used in a variety of superconducting qubit experiments, when excited by a steady, but not necessarily small, ac tone. We show that this model can be derived directly from a circuit description of some recent qu...
1109.2490v1
2011-11-09
Stabilization by switching control methods
In this paper we consider some stabilization problems for the wave equation with switching. We prove exponential stability results for appropriate damping coefficients. The proof of the main results is based on D'Alembert formula and some energy estimates.
1111.2171v1
2012-04-09
The Kato Smoothing Effect for Regularized Schrödinger Equations in Exterior Domains
We prove, under the exterior geometric control condition, the Kato smoothing effect for solutions of an inhomogenous and damped Schr\"odinger equation on exterior domains.
1204.1904v1
2012-04-26
Well-posedness and long time behavior in nonlinear dissipative hyperbolic-like evolutions with critical exponents
These lectures present the analysis of stability and control of long time behavior of PDE models described by nonlinear evolutions of hyperbolic type. Specific examples of the models under consideration include: (i) nonlinear systems of dynamic elasticity: von Karman systems, Berger's equations, Kirchhoff - Boussinesq ...
1204.5864v1
2012-06-15
Comment on "Anisotropic Critical Magnetic Fluctuations in the Ferromagnetic Superconductor UCoGe"
We have presented the potential explanation of nonvanishing at q=0 Landau damping measured experimentally in ferromagnetic compounds UGe2 and UCoGe based on possible intersection of the Fermi sheets corresponding different bands.
1206.3468v1
2012-06-21
Interaction between an Isotropic Nanoparticle and Drifting Electrons in a Quantum Well
A hybrid system composed of an isotropic nanoparticle and a semiconductor heterostructure with a quantum well has been considered. The nanoparticle is supposed to be polarizable in an external electric field. A theoretical model of the hybrid system is substantiated and formulated. Exact solutions of the model equation...
1206.4782v1
2012-10-02
Coherence and Stimulated Emission in the Tavis-Cummings Model: A Quantum Description of the Free Induction Signal and Radiation Damping in Magnetic Resonance
We numerically solve the Liouville equation for the Tavis Cummings model of multiple spins coupled to a lossless single mode cavity, starting from an initial condition with small numbers of fully polarized spins tipped by a specified angle, and the cavity in its ground Fock state. Time evolution of the magnetizations a...
1210.0868v2
2012-10-11
Experimental estimations of viscoelastic properties of multilayer damped plates in broad-band frequency range
Regarding lightweighting structures for aeronautics, automotive or construction applications, the level of performance of solutions proposed in terms of damping and isolation is fundamental. Hence multilayered plate appears as an interesting answer if damping performances are properly optimized. In this paper, a novel ...
1210.3333v3
2012-11-02
Damping of mechanical vibrations by free electrons in metallic nanoresonators
We investigate the effect of free electrons on the quality factor (Q) of a metallic nanomechanical resonator in the form of a thin elastic beam. The flexural and longitudinal modes of the beam are modeled using thin beam elasticity theory, and simple perturbation theory is used to calculate the rate at which an externa...
1211.0450v1
2013-01-14
Two-qubit mixed states more entangled than pure states: Comparison of the relative entropy of entanglement for a given nonlocality
Amplitude damping changes entangled pure states into usually less-entangled mixed states. We show, however, that even local amplitude damping of one or two qubits can result in mixed states more entangled than pure states if one compares the relative entropy of entanglement (REE) for a given degree of the Bell-Clauser-...
1301.2969v2
2013-07-02
The ESO UVES Advanced Data Products Quasar Sample - I. Dataset and New N_HI Measurements of Damped Absorbers
We present here a dataset of quasars observed with the Ultraviolet Visual Echelle Spectrograph (UVES) on the VLT and available in the ESO UVES Advanced Data Products archive. The sample is made up of a total of 250 high resolution quasar spectra with emission redshifts ranging from 0.191 < z_em <6.311. The total UVES e...
1307.0678v2
2013-08-23
Stabilization of second-order evolution equations with time delay
We consider second-order evolution equations in an abstract setting with damping and time delay and give sufficient conditions ensuring exponential stability. Our abstract framework is then applied to the wave equation, the elasticity system and the Petrovsky system.
1308.5106v1
2013-09-21
Bottomonium suppression at $\sqrt{s_{NN}}=2.76$ TeV using model based on color screening and gluonic dissociation with collisional damping
We present a model to explain the bottomonium suppression in Pb+Pb collisions at mid rapidity obtained from Large Hadron Collider (LHC) energy, $\sqrt{s_{NN}}=2.76$ TeV. The model consists of two decoupled mechanisms namely, color screening during bottomonium production followed by gluon induced dissociation along with...
1309.5467v2