Affordable Access

Access to the full text

A note on entropy of de Sitter black holes

Authors
  • Bhattacharya, Sourav1, 2
  • 1 University of Crete, ITCP and Department of Physics, Heraklion, 70013, Greece , Heraklion (Greece)
  • 2 Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune University Campus, Pune, 411007, India , Pune (India)
Type
Published Article
Journal
The European Physical Journal C
Publisher
Springer-Verlag
Publication Date
Mar 02, 2016
Volume
76
Issue
3
Identifiers
DOI: 10.1140/epjc/s10052-016-3955-6
Source
Springer Nature
Keywords
License
Green

Abstract

A de Sitter black hole or a black hole spacetime endowed with a positive cosmological constant has two Killing horizons—a black hole and a cosmological event horizon surrounding it. It is natural to expect that the total Bekenstein–Hawking entropy of such spacetimes should be the sum of the two horizons’ areas. In this work we apply the recently developed formalism using the Gibbons–Hawking–York boundary term and the near horizon symmetries to derive the total entropy of such two horizon spacetimes. We construct a suitable general geometric set up for general stationary axisymmetric spacetimes with two or more than two commuting Killing vector fields in an arbitrary spacetime dimensions. This framework helps us to deal with both horizons on an equal footing. We show that in order to obtain the total entropy of such spacetimes, the near horizon mode functions for the diffeomorphism generating vector fields have to be restricted in a certain manner, compared to the single horizon spacetimes. We next discuss specific known exact solutions belonging to the Kerr–Newman or the Plebanski–Demianski–de Sitter families to show that they fall into the category of our general framework. We end with a sketch of further possible extensions of this work.

Report this publication

Statistics

Seen <100 times