Entropy of Radiation with Dynamical Gravity

TL;DR

This paper investigates the entanglement entropy in a holographic black string model with dynamical gravity, exploring conditions for unitarity and Page curve behavior in the context of quantum gravity.

Contribution

It introduces a new parameter via a DGP term in a doubly holographic model to analyze unitarity and entropy evolution.

Findings

Identification of parameter regimes with unitary entropy evolution

Conditions under which the Page curve is realized

Extension of previous holographic entropy models

Abstract

We compute the subregion entanglement entropy for a doubly holographic black string model. This system consists of a non-gravitating bath and a gravitating brane, where we incorporate dynamic gravity by adding a DGP term. This opens up a new parameter directly extending previous work and raises an important question about unitarity. In this note we analyse which theories in this big parameter space, will have unitary entropy evolution, in particular, we will distinguish which of those will follow a Page curve.