Subsystem eigenstate thermalization hypothesis for entanglement entropy in CFT

Understand

We investigate a weak version of subsystem eigenstate thermalization hypothesis (ETH) for a two-dimensional large central charge conformal field theory by comparing the local equivalence of high energy state and thermal state of canonical ensemble.

• We evaluate the single-interval R\'enyi entropy and entanglement entropy for a heavy primary state in short interval expansion.
• We verify the results of R\'enyi entropy by two different replica methods.
• We find nontrivial results at the eighth order of short interval expansion, which include an infinite number of higher order terms in the large central charge expansion.