Equidistribution for standard pairs in planar dispersing billiard flows

We prove exponential correlation decay in dispersing billiard flows on the 2-torus assuming finite horizon and lack of corner points. With applications aimed at describing heat conduction, the highly singular initial measures are concentrated here on 1-dimensional submanifolds (given by standard pairs) and the observables are supposed to satisfy a generalized H"older continuity property. The result is based on the exponential correlation decay bound of Baladi, Demers and Liverani obtained recentlyfor H"older continuous observables in these billiards. The model dependence of the bounds is also discussed.