2007/05/31 by Tomáš Liko, Tomas Liko · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #gr-qc
paper · pdf · doi:10.1103/physrevd.77.064004
published as Phys.Rev.D77:064004,2008 · 8 pages; 1 figure; v2: 9 pages; some comments added at the end; 3 references added; v3: minor corrections; v4: some corrections; discussion added on black-hole mergers and violations of the second law; 2 references added; v5: minor corrections; v6: final corrections to match PRD version
arxiv created 2008/03/05 · openalex publication_date 2008/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We show that the Gauss-Bonnet term can have physical effects in four dimensions. Specifically, the entropy of a black hole acquires a correction term that is proportional to the Euler characteristic of the cross sections of the horizon. While this term is constant for a single black hole, it will be a nontrivial function for a system with dynamical topologies such as black-hole mergers: it is shown that for certain values of the Gauss-Bonnet parameter, the second law of black-hole mechanics can be violated.