Large deviations for random walks on Gromov-hyperbolic spaces

Abstract

Let $\Gamma$ be a countable group acting on a geodesic Gromov-hyperbolic metric space $X$ and $\mu$ a probability measure on $\Gamma$ whose support generates a non-elementary subsemigroup. Under the assumption that $\mu$ has a finite exponential moment, we establish large deviations results for the distance and the translation length of a random walk with driving measure $\mu$. From our results, we deduce a special case of a conjecture regarding large deviations of spectral radii of random matrix products.

V1 --> V2: Modifications and small corrections after the referee reports, to appear in Ann. Sci. Ec. Norm. Super. (50 pages)