Title :

Equilibration, generalized equipartition, and diffusion in dynamical Lorentz gases

Author(s) :

De Bievre, Stephan [Auteur]
Quantitative methods for stochastic models in physics [MEPHYSTO]
Parris, Paul [Auteur]
Department of Physics

Journal title :

Journal of Statistical Physics

Pages :

356-385

Publisher :

Springer Verlag

Publication date :

2011

ISSN :

0022-4715

English keyword(s) :

Thermal equilibrium
Equipartition
Diffusion

HAL domain(s) :

Mathématiques [math]/Physique mathématique [math-ph]
Physique [physics]/Matière Condensée [cond-mat]/Mécanique statistique [cond-mat.stat-mech]

English abstract : [en]

We demonstrate approach to thermal equilibrium in the fully Hamiltonian evolution of a dynamical Lorentz gas, by which we mean an ensemble of particles moving through a $d$-dimensional array of fixed soft scatterers that ...
Show more >We demonstrate approach to thermal equilibrium in the fully Hamiltonian evolution of a dynamical Lorentz gas, by which we mean an ensemble of particles moving through a $d$-dimensional array of fixed soft scatterers that each possess an internal harmonic or anharmonic degree of freedom to which moving particles locally couple. We analytically predict, and numerically confirm, that the momentum distribution of the moving particles approaches a Maxwell-Boltzmann distribution at a certain temperature $T$, provided that they are initially fast and the scatterers are in a sufficiently energetic but otherwise arbitrary stationary state of their free dynamics--they need not be in a state of thermal equilibrium. The temperature $T$ to which the particles equilibrate obeys a generalized equipartition relation, in which the associated thermal energy $k_B T$ is equal to an appropriately defined average of the scatterers' kinetic energy. In the equilibrated state, particle motion is diffusive.Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Laboratoire Paul Painlevé - UMR 8524

Source :

Harvested from HAL