"Gravastars: A Matryoshka Doll Theory for Stellar Structures"
Physicists at Goethe University Frankfurt have proposed a new theoretical solution to the field equations of general relativity, describing the existence of a gravastar inside another gravastar, which they have named "nestar." This hypothetical celestial object resembles a matryoshka doll and is made up of nested gravastars. Unlike black holes, gravastars do not have an event horizon or a singularity at their core, and their surface is represented by a wafer-thin skin of ordinary matter. While the creation of nestars remains unknown, exploring the mathematical properties of these solutions contributes to a better understanding of black holes.