a1 Institute of Mathematics, Helsinki University of Technology, 02150 Espoo, Finland
We show the stability in the sense of α-congruence of dispersive (Sinai) planar billiards that are Bernoulli flows. The perturbations are either billiards on slightly altered tables or geodesic flows on nearby manifolds.
(Received June 01 1989)
(Revised April 30 1990)
† Research partially supported by the Academy of Finland and the Emil Aaltonen Foundation.