Correlations and spectra of triangular billiards

We consider the motion of a point particle in right triangular billiards for which acute angles are not rationally connected to pi. We consider in particular the behaviour of correlations for a particular phase space variable. The behaviour is compatible with the mixing character of the dynamics, even though large fluctuations are exhibited. By Fourier transforming correlation functions we may as well analyse scaling properties of the spectral measure: both dynamical and spectral features are quite similar to what observed in a class of quantum kicked systems.