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

Sushant G. Ghosh; Sunil D. Maharaj

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arXiv · 2003.09841

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

Sushant G. Ghosh·Sunil D. Maharaj

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Abstract

Recently Glavan and Lin [Phys. Rev. Lett. 124, 081301 (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 $D \rightarrow 4$, 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 $\alpha \rightarrow 0$, 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 $\alpha \rightarrow 0$, reduced exactly to \emph{vis-$\grave{a}$-vis} 4D black holes of GR.

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Sushant G. Ghosh, Sunil D. Maharaj. 2020-03-22. Radiating black holes in the novel 4D Einstein-Gauss-Bonnet gravity. https://arxiv.org/abs/2003.09841

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