Revisiting the nonsingular black holes in the 4-dimensional regularized Lovelock gravity

Abstract

Static, spherically symmetric nonsingular/regular black holes in the vacuum 4-dimensional Lovelock gravity are revisited. We follow the footsteps of Changjun Gao et al in their recent work (Gao et al. in Phys Dark Univ 31:100754, 2021) where they introduced nonsingular black holes in regularized Lovelock gravity and studied their physical properties. In addition to what already has been done, we introduce conditions to be satisfied by any nonsingular black hole. Unfortunately, the nonsingular black holes introduced in Gao et al. (Phys Dark Univ 31:100754, 2021) do not fulfill these conditions and therefore are actually singular. We also give an example of a regular black hole in 4-dimensional infinite-order Lovelock gravity which can be considered as an alternative to the Schwarzschild black hole. It is shown that this black hole is thermally stable.