Future-null singularity due to gravitational collapse

TL;DR

This paper presents a new gravitational collapse model resulting in a future-null singularity, differing from traditional LTB models, with unique causal structure demonstrated through conformal diagrams.

Contribution

It introduces a novel collapse scenario leading to a future-null singularity, expanding understanding of possible end-states in gravitational collapse.

Findings

Identifies a collapse model with a future-null singularity

Shows the distinct causal structure via conformal diagrams

Differentiates from LTB spacetime end-states

Abstract

In the case of unhindered gravitational collapse of matter cloud governed by the Lemaitre-Tolman-Bondi (LTB) spacetime, the end-state singularity is either locally visible, globally visible or completely hidden. We have a past-null singularity in the first two cases while a future-spacelike singularity in the last case. Here, we show an example of a gravitational collapse model whose end-state is a future-null-singularity (it has a causal property that is unlike the cases involving LTB spacetime). We depict such a distinct causal structure of the singularity by conformal diagrams.