Hawking radiation and entropy in de Sitter spacetime

TL;DR

This paper investigates Hawking radiation in higher-dimensional Schwarzschild-de Sitter spacetime, revealing a non-thermal spectrum linked to horizon entropy changes, consistent with unitarity, and confirming total entropy as sum of horizon entropies.

Contribution

It provides a detailed analysis of Hawking radiation considering energy conservation and horizon interactions, extending understanding of entropy in de Sitter spacetime.

Findings

Radiation spectrum is non-thermal and related to entropy changes.

Total de Sitter entropy equals sum of black hole and cosmological horizon entropies.

Results are consistent with the unitarity principle.

Abstract

Using the analytic extension method, we study Hawking radiation of an $(n + 4)$-dimensional Schwarzschild-de Sitter black hole. Under the condition that the total energy is conserved, taking the reaction of the radiation of particles to the spacetime into consideration and considering the relation between the black hole event horizon and cosmological horizon, we obtain the radiation spectrum of de Sitter spacetime. This radiation spectrum is no longer a strictly pure thermal spectrum. It is related to the change of the Bekenstein-Hawking(B-H) entropy corresponding the black hole event horizon and cosmological horizon. The result satisfies the unitary principle. At the same time, we also testify that the entropy of de Sitter spacetime is the sum of the entropy of black hole event horizon and the one of cosmological horizon.