$T\bar{T}$-deformed Entanglement Entropy for Integrable Quantum Field Theory

TL;DR

This paper computes the entanglement entropy in integrable quantum field theories deformed by the $T\bar{T}$ operator, revealing how the deformation affects the UV limit and effective central charge using form factor bootstrap methods.

Contribution

It introduces a method to calculate $T\bar{T}$-deformed entanglement entropy in IQFTs via form factor bootstrap, analyzing the effects of different bootstrap solutions.

Findings

UV entanglement entropy retains form but with deformed central charge

Deformed form factors are obtained for branch-point twist fields

IR corrections remain unaffected by the $T\bar{T}$ deformation

Abstract

We calculate the $T\bar{T}$-deformed entanglement entropy for integrable quantum field theories (IQFTs) using the form factor bootstrap approach. We solve the form factor bootstrap axioms for the branch-point twist fields and obtain the deformed form factors. Using these form factors, we compute the deformed von Neuman entropy up to two particle contributions. The solution of the form factor axioms is not unique. We find that for the simplest solution of the bootstrap axioms, the UV limit of the entanglement entropy takes the same form as the undeformed one, but the effective central charge is deformed. For solutions with additional CDD-like factors, we can have different behaviors. The IR corrections, which only depends on the particle spectrum is untouched.