We study an area preserving parabolic map which emerges from the Poincaré map of a billiard particle inside an elongated triangle. We provide numerical evidence that the motion is ergodic and mixing. Moreover, when considered on the cylinder, the motion appears to follow a Gaussian diffusive process.

• Received 23 March 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.4261