What are black holes? Gravastars are like a matryoshka doll

The interior of black holes is an impenetrable mystery to physics. In 1916, Karl Schwarzschild proposed a solution to the equations of general relativity, according to which there is a singularity at the center of a black hole, the point where time and space do not exist and where all the laws of physics are invalid. Schwarzschild's proposal and its consequences – for example, the impossibility of obtaining information from a black hole – were so strange that for decades it was known only among theorists. It gained popularity with the discovery of the first black hole in 1971. A few decades later, a black hole was discovered in the center of our galaxy.

In 2001, Paul Mazur and Emil Mottola proposed a new solution to Einstein's equations. They were meant to be gravastars. They have many advantages over black holes. On the one hand, they have the same size and mass, and exert an equally strong gravitational influence on their surroundings. However, unlike black holes, gravastars do not have an event horizon, a boundary beyond which anything can go, which is controversial among physicists, nor do they possess singularities. Instead, dark energy resides at the center of the gravastar, exerting a strong negative pressure pressing down on the gravastar. Furthermore, unlike black holes, gravastars have an extremely thin physical surface. Its thickness tends to zero.

Now Daniel Jampolski and Professor Luciano Rizzola from the University of Frankfurt am Main They came Solve Einstein's equations describing gravastars within gravastars. They called this virtual body “nestar”, from the English word “nested” (entering one into another).