https://doi.org/10.1140/epjp/s13360-022-03383-2
Regular Article
Thermal density matrix breaks down the Page curve
Steklov Mathematical Institute of Russian Academy of Sciences, Gubkin Str. 8, 119991, Moscow, Russia
Received:
24
September
2022
Accepted:
10
October
2022
Published online:
28
October
2022
In this paper, we study entanglement islands and the Page curve in the eternal four-dimensional Schwarzschild black hole surrounded by finite temperature conformal matter. By finite temperature conformal matter, we mean the matter described by the thermal density matrix, rather than the usually considered matter in the vacuum state. We take the matter and the black hole at different temperatures and calculate the entanglement entropy for such a setup using the s-wave approximation. As a result, we obtain that at late times the island prescription leads to the exponential growth of the entanglement entropy of conformal matter in this thermal vacuum.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2022. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.