the first part of the talk will be an introduction to the general
theory of random walks on groups with some classical results on entropy,
rate of escape ... . For hyperbolic groups, these probabilistic objects
have geometric counterparts in terms of Gromov boundary, quasi-conformal
measures ... I will mention applications and open questions.
Finally I will discuss fluctuation results - like the central limit
theorem - in particular a recent work with A. Sisto on deviation
inequalities for random walks on cylindrically hyperbolic groups.