On one-loop entanglement entropy of two short intervals from OPE of twist operators

摘要: We investigate the one-loop entanglement entropy of two short intervals with small cross ratio x on a complex plane in two-dimensional conformal field theory (CFT) using operator product expansion of twist operators. We focus on the one-loop entanglement entropy instead of the general order n R\'enyi entropy, and this makes the calculation much easier. We consider the contributions of stress tensor to order x10, contributions of W3 operator to order x12, and contributions of W4 operator to order x14. The CFT results agree with the ones in gravity.