Back to boundaries in billiards (Q6559091)

The main result of this work is that for a large class of hyperbolic billiards, the process of hitting and escaping through a hole in the boundary of a billiard table is asymptotically Poissonian. This, in contrast to known results in this subject, shows that the Poisson approximation does not depend on fast correlation decay. Remarkably, the result formulated in the main theorem uses only some natural general, and easy to verify, conditions.\N\NThe paper is well written and all technical steps are explained in a clear manner. The reference list is well chosen with useful cross references to former studies. In particular, previously known results in this research area are well motivated and discussed.