Modular-invariance framework for CFT partition function on torus (Cardy 1986 Nucl Phys B 270, 186). Setup: 2D CFT on torus T^2 = C/(Z + tau Z) has partition function Z(tau) = Tr_H q^{L_0 - c/24} q-bar^{L_0-bar - c/24} with q = e^{2 pi i…
Modular-invariance framework for CFT partition function on torus (Cardy 1986 Nucl Phys B 270, 186). Setup: 2D CFT on torus T^2 = C/(Z + tau Z) has partition function Z(tau) = Tr_H q^{L_0 - c/24} q-bar^{L_0-bar - c/24} with q = e^{2 pi i…