V.R477 — BKL Billiard Domain = T² Moduli Space (Hartnoll-Yang 2025)

Three-part remark: (1) BKL billiard domain H/SL(2,Z) is the moduli space of T², directly identifying it with tau's BH horizon parameter space (tau-effective from V.T109). (2) tau dissolves the singularity: No Interior Singularity (V.P91) topologically excludes the BKL cusp; Maass boundary conditions express this exclusion. (3) Conjectural spectral coincidence: first Maass spectral parameter epsilon_1 = 9.534 vs tau's diagonal T² eigenvalue lambda_{1,1} = 1 + iota_tau^{-2} = 9.585 at 0.53% (operator normalisation identification pending). Fermionic Witten index degeneracy (p-1)/2 per prime matches tau's bipolar primitive winding count. Reference: Hartnoll-Yang arXiv:2502.02661.