ERGODIC BILLIARDS
Bunimovich Stadium · Sinai Billiard · Chaotic vs Integrable
Table geometry:
Bunimovich stadium (chaotic)
Sinai billiard (chaotic)
Circle (integrable)
Rectangle (integrable)
Stadium length:
1.0
Angle θ:
30
°
Num trajectories:
3
Trace length:
400
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The
Bunimovich stadium
(1979) is a rectangle with semicircular caps — a paradigmatic ergodic billiard. Unlike integrable systems (circle, rectangle), nearby trajectories diverge exponentially. Lyapunov exponent λ > 0 ensures ergodic phase-space coverage.