Paper detail

Localization and number of visited valleys for a transient diffusion in random environment

We consider a transient diffusion in a $(-κ/2)$-drifted Brownian potential $W\_κ$ with $0\textless{}κ\textless{}1$. We prove its localization at time $t$ in the neighborhood of some random points depending only on the environment, which are the positive $h\_t$-minima of the environment, for $h\_t$ a bit smaller than $\log t$. We also prove an Aging phenomenon for the diffusion, a renewal theorem for the hitting time of the farthest visited valley, and provide a central limit theorem for the number of valleys visited up to time $t$. The proof relies on a decomposition of the trajectory of $W\_κ$ in the neighborhood of $h\_t$-minima, with the help of results of A. Faggionato, and on a precise analysis of exponential functionals of $W\_κ$ and of $W\_κ$ Doob-conditioned to stay positive.