Instability of Black Holes with a Gauss–Bonnet Term

Wha-Keun Ahn; Bogeun Gwak; Bum-Hoon Lee; Wonwoo Lee

doi:10.1140/epjc/s10052-015-3568-5

EPJ

Instability of Black Holes with a Gauss–Bonnet Term

Wha-Keun Ahn¹, Bogeun Gwak¹^*, Bum-Hoon Lee¹^,2^,3 and Wonwoo Lee¹

¹ Center for Quantum Spacetime, Sogang University, Seoul, 121-742, Korea
² Department of Physics, Sogang University, Seoul, 121-742, Korea
³ Asia Pacific Center for Theoretical Physics, Pohang, 790-784, Korea

Received: 30 March 2015
Accepted: 13 July 2015
Published online: 15 August 2015

Abstract

We investigate the fragmentation instability of hairy black holes in the theory with a Gauss–Bonnet (GB) term in asymptotically flat spacetime. Our approach is through the non-perturbative fragmentation instability. By this approach, we investigate whether the initial black hole can be broken into two black holes by comparing the entropy of the initial black hole with the sum of those of two fragmented black holes. The relation between the black hole instability and the GB coupling with dilaton hair are presented. We describe the phase diagrams with respect to the mass of the black hole solutions and coupling constants. We find that a perturbatively stable black hole can be unstable under fragmentation.