Extreme events for horocycle flows

Abstract We prove extreme value laws for cusp excursions of the horocycle flow in the case of surfaces of constant negative curvature. The key idea of our approach is to study the hitting time distribution for shrinking Poincaré sections that have a particularly simple scaling property under the action of the geodesic flow. This extends the extreme value law of Kirsebom and Mallahi-Karai (2022 arXiv:2209.07283) for cusp excursions for the modular surface. Here we show that the limit law can be expressed in terms of Hall’s formula for the gap distribution of the Farey sequence.