Page Curve and Island in EGB gravity

TL;DR

This paper investigates the black hole information paradox in three-dimensional Gauss-Bonnet gravity using the quantum extremal island approach, demonstrating the emergence of the Page curve and analyzing entropy modifications.

Contribution

It applies the quantum extremal island method to EGB gravity, revealing how the Page curve arises in this lower-dimensional setting and identifying modifications to entropy and Page time.

Findings

Page curve is recovered in EGB gravity with islands.

Quantum extremal surface is located outside the horizon.

Entropy and Page time are modified in this setup.

Abstract

In this paper, the information paradox on lower-dimensional Gauss-Bonnet gravity known as a three-dimensional EGB black hole is studied using the quantum extremal island approach. For that, we connect an auxiliary flat bath system to this timelike singularity spacetime and estimate the entropy of hawking radiation in its asymptotic regions when gravity is weak. The addition of island areas to the entanglement wedge of radiation causes its entropy to obey the Page curve, as shown. The quantum extremal surface, or island boundary, is located outside the horizon. This yields a time-independent equation for Hawking radiation fine-grained entropy that is compatible with the appropriate Page curve. We also discover the modifications to this entropy and Page time.