Koiller J., Markarian R., Oliffson Kmaphorst S., Pinto de Carvalho S.
A Geometric Framework for time-dependent Billiards
(42K, LaTeX)

ABSTRACT.  Billiards with moving boundaries can be viewed as the limiting
case of rigid ones, constructed on an augmented configuration space.
The metric is defined by a new kinetic energy, singular in the limit.
We describe the symplectic structure  of the time-dependent billiard map
and specify suitable coordinates for the convex case of dimension 2.