Unmasking black hole impostors: discovering the true nature of astrophysical black holes

The past decade has witnessed major breakthroughs in astrophysical observations.

The LIGO-Virgo collaboration´s detection of gravitational waves (GW), and images taken by the Event Horizon Telescope (EHT) have created unprecedented opportunities to probe the nature of highly dense and compact objects (UCO) in our universe. Current observations are consistent with these objects being black holes (BH), without being exclusive.

However, BHs lead to paradoxes between well understood physical principles. A way out is that instead of being BHs, these are mimickers—objects that very closely mimic BHs. Among the handful of such objects that have been constructed, most models are premature.

To uncover the true nature of the UCOs in our universe, it is crucial to fully develop the theory of mimickers; and to find out how to distinguish them from BHs in astrophysical observations.

This is what this projects aims to do.To begin with, I will focus on a particularly promising mimicker—a "black shell".

Using theoretical modeling and numerical simulations, this three-year project aims to fully develop them into realistic candidates for UCOs that exist in our universe. This will further lead to ways to distinguish them, and other mimickers, from BHs in astrophysical observations.

This is truly the need of the hour, given the lack of a concrete understanding of UCOs, and the extraordinary ability to scrutinize them that current and future GW observations and EHT data promise to provide.