Random Matrix Theory

Wigner semicircle law & GOE/GUE level spacing statistics

Ensemble Parameters

Wigner semicircle:
ρ(λ) = (2/πR²)√(R²-λ²)
R = 2σ√N

Level spacing s = λ_{n+1}-λ_n (unfolded):
GOE: P(s) ≈ (πs/2)exp(-πs²/4) (Wigner surmise)
GUE: P(s) ≈ (32s²/π²)exp(-4s²/π)
Poisson: P(s) = exp(-s)

Level repulsion: GOE β=1, GUE β=2.