Press–Schechter halo mass function

Layer 1 — Physicsin the cosmology subtree

dn/dM ∝ (ρ̄/M²)(δ_c/σ(M)) exp(-δ_c²/(2σ²))|d ln σ/d ln M|; Sheth–Tormen correction for ellipsoidal collapse. Cluster abundance cosmology.