Bi-partite entanglement entropy in massive two-dimensional quantum field theory

TL;DR

This paper proposes a universal exponential correction to bipartite entanglement entropy saturation in massive 2D quantum field theories, independent of scattering details, based on form factor analyticity.

Contribution

It introduces a universal correction term for entanglement entropy in massive 2D QFTs, extending previous integrable model results to non-integrable cases.

Findings

Exponential correction depends only on particle content.

Result is conjectured to be universal for all massive 2D models.

Links entanglement entropy correction to pair creation processes.

Abstract

Recently, Cardy, Castro Alvaredo and the author obtained the first exponential correction to saturation of the bi-partite entanglement entropy at large region length, in massive two-dimensional integrable quantum field theory. It only depends on the particle content of the model, and not on the way particles scatter. Based on general analyticity arguments for form factors, we propose that this result is universal, and holds for any massive two-dimensional model (also out of integrability). We suggest a link of this result with counting pair creations far in the past.