Collapsing dust thin shells in Einstein-Gauss-Bonnet gravity

Abstract

We investigate gravitational collapse of a spherically symmetric thin shell in the Einstein-Gauss-Bonnet (EGB) gravity. Under the recently proposed 4D limit, we find that the collapsing shell will be bounced back at a small radius, without forming a singularity. This bouncing behavior is similar to those of a test particle and a homogeneous spherical dust star, in accordance with the expectation that the Gauss-Bonnet term will modify the small scale behavior of the Einstein gravity. We analyze the causal structure of the dynamic spacetime that represents the bouncing process, finding that the thin shell has an oscillation behavior on the Penrose diagram, which means that the thin shell results in a novel type of black hole with respect to observers outside the event horizon that the collapse forms. We also find that the weak cosmic censorship conjecture holds in this model. Further implications of such a regular gravitational collapse are discussed.

References in corpus (7)

• On Taking the $D\to 4$ limit of Gauss-Bonnet Gravity: Theory and Solutions
• Final fate of spherically symmetric gravitational collapse of a dust cloud in Einstein-Gauss-Bonnet gravity
• Comment on "Einstein-Gauss-Bonnet Gravity in Four-Dimensional Spacetime"
• Dust collapse in 4D Einstein-Gauss-Bonnet gravity
• Hawking evaporation of Einstein-Gauss-Bonnet AdS black holes in $D⩾4$ dimensions
• Collapsing and static thin massive charged dust shells in a Reissner-Nordström black hole background in higher dimensions
• Generalized Darmois-Israel junction conditions