Primary operators, conformal blocks, OPE coefficients, 2D CFT correlators (Virasoro algebra)
OPE: O₁(z)O₂(0) ~ Σ_k C¹²_k z^(hk-h1-h2) z̄^(h̄k-h̄1-h̄2) Ok(0)
4-pt: ⟨O₁O₂O₃O₄⟩ = Σ_p C¹²ₚ C³⁴ₚ |z|^(2(hₚ-h₁-h₂)) F(c,hᵢ,hₚ;z)
CFT bootstrap: the 4-point function is fully determined by spectrum (hₙ,h̄ₙ) and OPE coefficients C_{ij}^k via crossing symmetry F(z)=F(1-z). Conformal blocks F are (partial) eigenfunctions of the Casimir. Virasoro algebra: [Lₙ,Lₘ]=(n-m)L_{n+m}+c/12·n(n²-1)δ_{n+m,0}. Kac table: degenerate representations at c<1 with h_{r,s}=[(rp'-sp)²-(p'-p)²]/(4pp').