Island in the Presence of Higher Derivative Terms

TL;DR

This paper calculates the entanglement entropy of Hawking radiation in higher derivative gravity models, demonstrating the emergence of the Page curve due to island contributions even in non-unitary theories.

Contribution

It extends the island formula to higher derivative gravitational models and computes the entropy for various black holes, showing the universality of the Page curve.

Findings

Entropy follows the Page curve with island contributions.

Higher derivative terms do not prevent the emergence of the Page curve.

The results apply to both asymptotically flat and AdS black holes.

Abstract

Using extended island formula we compute entanglement entropy of Hawking radiation for black hole solutions of certain gravitational models containing higher derivative terms. To be concrete we consider two different four dimensional models to compute entropy for both asymptotically flat and AdS black holes. One observes that the resultant entropy follows the Page curve, thanks to the contribution of the island, despite the fact that the corresponding gravitational models might be non-unitary.