http://arxiv.org/abs/2003.12492
A (3+1)-dimensional Einstein-Gauss-Bonnet theory of gravity has been recently formulated as the $D \to 4$ limit of the higher dimensional field equations after the rescaling of the coupling constant. This theory is a nontrivial generalization of General Relativity, it bypasses the Lovelock’s theorem, and avoids the Ostrogradsky instability. This approach has been extended to the four-dimensional Einstein-Lovelock gravity. Here we study the eikonal gravitational instability of asymptotically flat, de Sitter and anti-de Sitter black holes in the four dimensional Einstein-Gauss-Bonnet and Einstein-Lovelock theories. We find parametric regions of the eikonal instability for various orders of the Lovelock gravity, values of coupling and cosmological constants, and share the code which allows one to construct the instability region for an arbitrary set of parameters.
R. Konoplya and A. Zhidenko
Mon, 30 Mar 20
34/44
Comments: 6 pages, 3 figures, 1 ancillary Mathematica(R) notebook