Shadow of higher dimensional collapsing dark star and blackhole

Abstract

The shadow of a black hole or a collapsing star is of great importance as we can extract important properties of the object and of the surrounding spacetime from the shadow profile. It can also be used to distinguish different types of black holes and ultra compact objects. In this work, we have analytically calculated the shadow of a higher dimensional collapsing dark star, described by higher dimensional Vaidya metric, by choosing a slightly generalized version of Misner--Sharp mass function. We have also numerically investigated the properties of the shadows of the black holes and the collapsing stars for a slightly more general mass function. Examining the potential influence of extra spatial dimensions on the shadow, we have explored the possibility of distinguishing higher dimensions from the standard four-dimensional spacetime.