The River Model of Gravitational Collapse

TL;DR

This paper introduces a novel model of gravitational collapse using Painleve-Gullstrand-Lemaitre coordinates, revealing non-singular bounce and wormhole formation scenarios with implications for analog gravity systems.

Contribution

It presents a new time-evolving model of gravitational collapse that includes bounce and wormhole solutions, expanding understanding of non-singular black hole and wormhole geometries.

Findings

Collapse can lead to a bounce and dispersal of matter.

Wormhole geometries can form under certain initial conditions.

Null convergence condition is violated only at specific transition points.

Abstract

We show that the transformation of a time-evolving spherically symmetric metric tensor into a Painleve-Gullstrand-Lemaitre form brings forth a few curious consequences. The time evolution describes a non-singular gravitational collapse, leading to a bounce and dispersal of all the clustered matter, or a wormhole geometry for certain initial conditions. The null convergence condition is violated only at the onset of bounce or the wormhole formation. As an example, the requirements to develop a Simpson-Visser wormhole/regular black-hole geometry is discussed. The solution can be regarded as a new time-evolving twin of sonic dumb holes found in analog gravity.