The universality of islands outside the horizon
Abstract
We systematically calculate the quantum extremal surface (QES) associated with Hawking radiation for general $D$dimensional ($D\geq2$) asymptotically flat (or AdS) eternal black holes using the island formula. {We collect the Hawking radiation particles by a nongravitational bath and} find that a QES exists in the nearhorizon region outside the black hole when $c\cdot G_{(D)}$ is smaller enough where $c$ is the central charge of the conformal matter and $G_{(D)}$ the {$D$dimensional} Newton constant. The locations of the QES in these backgrounds are obtained and the latetime radiation entropy saturates the two times of black hole entropy. Finally, we numerically check that the no island configuration exists once $c\cdot G_{(D)}$ exceeds a certain upper bound in twodimensional generalized dilaton theories (GDT).
 Publication:

arXiv eprints
 Pub Date:
 October 2021
 arXiv:
 arXiv:2110.07598
 Bibcode:
 2021arXiv211007598H
 Keywords:

 High Energy Physics  Theory
 EPrint:
 28 pages, 8 figures, 2 tables v2:minor changes in the text, references added