arXiv subjects

Jerome Chave

Publications and source records attributed to Jerome Chave.

2 recordsLinked to original sources

arXiv1999

Finite time and asymptotic behaviour of the maximal excursion of a random walk

We evaluate the limit distribution of the maximal excursion of a random walk in any dimension for homogeneous environments and for self-similar supports under the assumption of spherical symmetry. This distribution is obtained in closed form and is an approximation of the exact distribution comparable to that obtained by real space renormalization methods. Then we focus on the early time behaviour of this quantity. The instantaneous diffusion exponent $ν_n$ exhibits a systematic overshooting of the long time exponent. Exact results are obtained in one dimension up to third order in $n^{-1/2}$. In two dimensions, on a regular lattice and on the Sierpiński gasket we find numerically that the analytic scaling $ν_n \simeq ν+A n^{-ν}$ holds.

cond-mat.stat-mech↗

arXiv1998

Statistical and dynamical properties of the discrete Sinai model at finite times

We study the Sinai model for the diffusion of a particle in a one dimensional quenched random energy landscape. We consider the particular case of discrete energy landscapes made of random +/- 1 jumps on the semi infinite line Z+ with a reflecting wall at the origin. We compare the statistical distribution of the successive local minima of the energy landscapes, which we derive explicitly, with the dynamical distribution of the position of the diffusing particle, which we obtain numerically. At high temperature, the two distributions match only in the large time asymptotic regime. At low temperature however, we find even at finite times a clear correspondence between the statistical and dynamical distributions, with additional interesting oscillatory behaviors.

cond-mat.stat-mech↗