Radiating black holes in the novel 4D Einstein-Gauss-Bonnet gravity

Recently Glavan and Lin (2020) formulated a novel Einstein-Gauss-Bonnet gravity in which the Gauss-Bonnet coupling has been rescaled as alpha/(D - 4) and the 4D theory is defined as the limit D -> 4, which preserves the number degrees of freedom thereby free from the Ostrogradsky instability. We present exact spherically symmetric nonstatic null dust solutions in the novel 4D Einstein-Gauss-Bonnet gravity that bypasses the Lovelock theorem. Our solution represents radiating black holes and regains, in the limit alpha -> 0, the famous Vaidya black hole of general relativity (GR). We discuss the horizon structure of black hole solutions to find that the three horizon-like loci that characterizes its structure, viz. AH, EH and TLS have the relationship r(EH) < r(AH) = r(TLS). The charged radiating black holes in the theory, generalizing Bonnor-Vaidya black holes, are also considered. In particular our results, in the limit alpha -> 0, reduced exactly to vis-a-vis 4D black holes of GR. (C) 2020 Elsevier B.V. All rights reserved.