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We consider a particle living in $\mathbb{R}_+$, whose velocity is a positive recurrent diffusion with heavy-tailed invariant distribution when the particle lives in $(0,\infty)$. When it hits the boundary $x=0$, the particle restarts with…

Probability · Mathematics 2023-10-24 Loïc Béthencourt

The time-dependent spectral profile of a resonance line in a homogeneous expanding medium is studied by numerically solving an improved Fokker-Planck diffusion equation. The solutions are used to determine the time required to reach a…

Astrophysics · Physics 2009-10-22 George B. Rybicki , Ian P. Dell'Antonio

This paper is devoted to the linearized Vlasov-Poisson-Fokker-Planck system in presence of an external potential of confinement. We investigate the large time behaviour of the solutions using hypocoercivity methods and a notion of scalar…

Analysis of PDEs · Mathematics 2021-05-11 Lanoir Addala , Jean Dolbeault , Xingyu Li , Mohamed Lazhar Tayeb

We use a Monte Carlo approach to simulate the influence of the dipolar interaction on assemblies of monodisperse superparamagnetic ${\gamma}-Fe_{2}O_{3}$ nanoparticles. We have identified a critical concentration c*, that marks the…

Mesoscale and Nanoscale Physics · Physics 2010-11-12 D. Serantes , D. Baldomir , M. Pereiro , C. E. Hoppe , F. Rivadulla , J. Rivas

We consider self-similar approximations of nonlinear hyperbolic systems in one space dimension with Riemann initial data and general diffusion matrix. We assume that the matrix of the system is strictly hyperbolic and the diffusion matrix…

Analysis of PDEs · Mathematics 2008-12-16 K. T. Joseph , Philippe G. LeFloch

The incoherent dynamic structure factor of ortho-terphenyl has been measured by neutron time-of-flight and backscattering technique in the pressure range from 0.1 MPa to 240 MPa for temperatures between 301 K and 335 K. Tagged-particle…

Statistical Mechanics · Physics 2011-04-05 A. Toelle , H. Schober , J. Wuttke , F. Fujara

In response to recent proton spin relaxation-time measurements on NiCu(pba)(H$_2$O)$_3$$\cdot$2H$_2$O with ${pba}=1,3{-propylenebis(oxamato)}$, which is an excellent one-dimensional ferrimagnetic Heisenberg model system of spin-$(1,{1/2})$,…

Strongly Correlated Electrons · Physics 2009-10-31 Shoji Yamamoto

This work explores the solvability of a sixth-order Cahn--Hilliard equation with an inertial term, which serves as a relaxation of a higher-order variant of the classical Cahn--Hilliard equation. The equation includes a source term that…

Analysis of PDEs · Mathematics 2025-04-14 Pierluigi Colli , Gianni Gilardi

We consider the problem of relaxation in a one-dimensional system of interacting electrons. In the limit of weak interactions, we calculate the decay rate of a single-electron excitation, accounting for the nonlinear dispersion. The leading…

Strongly Correlated Electrons · Physics 2013-04-09 Zoran Ristivojevic , K. A. Matveev

A semi-explicit formula of solution to the boundary layer system for thermal layer derived from the compressible Navier-Stokes equations with the non-slip boundary condition when the viscosity coefficients vanish is given, in particular in…

Analysis of PDEs · Mathematics 2016-08-10 Cheng-Jie Liu , Ya-Guang Wang , Tong Yang

The nuclear magnetic relaxation time $T_1$ in ferrimagnetic insulators is calculated by a Raman process of hyperfine interaction with a meanfield approximation. It is found that the 1/$T_1$ on one site rapidly increases near the…

Materials Science · Physics 2020-10-07 Michiyasu Mori

We derive general properties of anomalous diffusion and nonexponential relaxation from the theory of tempered \alpha-stable processes. Its most important application is to overcome the infinite-moment difficulty for the \alpha-stable random…

Statistical Mechanics · Physics 2011-11-15 Aleksander Stanislavsky , Karina Weron , Aleksander Weron

We explore low temperature properties of quantum triangular Heisenberg antiferromagnets in two dimension in the vicinity of the quantum phase transition at zero temperature. Using the effective field theory described by the $SO(3)\times…

Strongly Correlated Electrons · Physics 2009-11-11 Satoshi Fujimoto

We calculate the magnetisation relaxation in the short-time regime for an ensemble of nanomagnets in the presence of a low-frequency external AC biasing field, at temperatures lower than the magnetic anisotropy energy of the individual…

Condensed Matter · Physics 2007-05-23 G. Rose , P. C. E. Stamp

The Pair Approximation method is applied to studies of the bilayer and multilayer magnetic systems with simple cubic structure. The method allows to take into account quantum effects related with non-Ising couplings. The paper adopts the…

Statistical Mechanics · Physics 2013-04-09 Karol Szałowski , Tadeusz Balcerzak

We extend the renormalized quasiparticle description of the symmetric Anderson model in a magnetic field $H$, developed in earlier work, to the non-symmetric model. The renormalized parameters are deduced from the low energy NRG fixed point…

Strongly Correlated Electrons · Physics 2009-11-13 J. Bauer , A. C. Hewson

This paper deals with the numerical study of a nonlinear, strongly anisotropic heat equation. The use of standard schemes in this situation leads to poor results, due to the high anisotropy. An Asymptotic-Preserving method is introduced in…

Numerical Analysis · Mathematics 2012-04-02 Alexei Lozinski , Jacek Narski , Claudia Negulescu

We use the Hamiltonian formulation of kinetic theory to perform a stability analysis of non-thermal fixed points in a non-Abelian plasma. We construct a perturbative expansion of the Fokker-Planck collision kernel in an adiabatic…

High Energy Physics - Phenomenology · Physics 2022-07-01 Aleksandr N. Mikheev , Aleksas Mazeliauskas , Jürgen Berges

Among the outstanding problems in the theory of supercooled liquids are the reasons for the rapid increase in their viscosity and relaxation times as the temperature is lowered towards the glass transition temperature, the non-exponential…

Disordered Systems and Neural Networks · Physics 2015-06-25 V. Halpern

The magnetization reversal rate via thermal creation of soliton pairs in quasi-1D ferromagnetic systems is calculated. Such a model describes e.g. the time dependent coercivity of elongated particles as used in magnetic recording media. The…

Condensed Matter · Physics 2009-10-22 Hans-Benjamin Braun