Photon redshift and the appearance of a naked singularity

TL;DR

This paper investigates how photons are redshifted when observed from outside a collapsing dust cloud forming a naked singularity, revealing different redshift behaviors depending on the singularity's strength.

Contribution

It provides a detailed analysis of photon redshift in naked singularity scenarios, distinguishing between weak and strong curvature cases and their observational signatures.

Findings

Photons from weak curvature naked singularities are finitely redshifted.

Photons from strong curvature naked singularities can be infinitely redshifted.

The study clarifies observational differences based on singularity strength.

Abstract

In this paper we analyze the redshift as observed by an external observer receiving photons which terminate in the past at the naked singularity formed in a Tolman-Bondi dust collapse. Within the context of models considered here it is shown that photons emitted from a weak curvature naked singularity are always finitely redshifted to an external observer. Certain cases of strong curvature naked singularities, including the self-similar one, where the photons are infinitely redshifted are also pointed out.