Time-Dependent Circular Billiard

الملخص EN

We investigate a time-dependent circular billiard with a two-frequency driving function and derive a new simplified form for the map, which is a symplectic nontwist map.

Stability boundaries and reconnection thresholds are derived for fixed points and period-two vortex pairs.

An island interspersal condition is derived such that neighboring island chains of the first frequency are exactly separated by those of the second.

The results show a strong enhancement of the KAM barrier to chaotic diffusion with increasing second frequency content and overall amplitude.