Circular Unitary Ensemble (CUE)

Random unitary matrices — eigenvalue repulsion on the unit circle

Parameters

Total eigenvalues:0
Mean spacing:0
Ensemble:CUE (β=2)
CUE: β=2 (complex). Eigenvalues of Haar-random U(N) lie on the unit circle.

Level spacing follows Wigner surmise: p(s) = (32/π²)s²exp(−4s²/π)

Key feature: eigenvalue repulsion — no clustering, unlike Poisson (no interactions → exp distribution).