Nestar, Matryoshka Gravestar

According to the discovery of physicists at Goethe University in Frankfurt, the nest could resemble a gravastar matryoshka doll. Credits: Daniel Jampolski and Luciano Rizzola, Goethe University Frankfurt

For information, the interior of black holes It's a real mystery. In 1916, German physicist Karl Schwarzschild provided a solution to the equations General relativity Einstein, according to which the center of a black hole consists of the so-called UniquenessIt is the point where space and time no longer exist. Here, according to the theory, all physical laws, including Einstein's general theory of relativity, are no longer applicable, and the principle of causality is suspended. No information can come out of the so-called Event horizon Black holes and singularities are a major source of nuisance to scientists. Perhaps for this reason, Schwarzschild's solution did not receive special attention outside the theoretical field for a long time, that is, until the discovery of the first black hole candidate in 1971, followed by the discovery of the black hole at the center. The Milky Way in 2000 and finally the first image of a black hole was taken by… Event horizon telescope Cooperation 2019

In 2001, Paul Mazur and Emil Mottola proposed a different solution to Einstein's field equations that gave rise to objects they called Gravity vacuum stars com. gravastar. Unlike black holes, gravastars have several advantages from a theoretical astrophysical point of view. On the one hand, they are almost as compact as black holes and have as much gravity on their surface as a black hole. On the other hand, gravastars They have no event horizon, i.e. boundaries beyond which information cannot be transmitted, and whose essence does not represent a uniqueness. The center of the Gravastar is actually composed of strange energy – dark – that exerts negative pressure in contrast to the massive gravitational force pressing down on the star. The Gravastar surface is represented by a very thin layer Ordinary material shellThe thickness of which is close to zero.

In a new study published in Classical quantum gravity Two theoretical physicists Daniel Jampolski H Luciano Rizzola from Goethe University Frankfurt They provided a solution to the field equations in general relativity that describe the existence of a gravastar inside another gravastar. They gave the name to this hypothetical celestial being Nestar (from English OverlappingOverlapping).

“The Star is like a Matryoshka doll,” explains Jampolski, who discovered the solution as part of his bachelor's thesis, under the supervision of Rizola. “Our solution of the field equations allows for a complete series of nested Gravastars.” While Mazur and Mottola argue that gravastar has a very thin shell of ordinary matter, nestar's matter shell is slightly thicker: “It's a little easier to imagine that something like this could exist.”

“It is nice that even 100 years after Schwarzschild provided his first solution to Einstein's field equations for the theory of general relativity, new solutions can still be found. It's a bit like finding a gold coin along a path that many others have already discovered. Unfortunately, we still have no idea how to create such a gravastar. “But even if stars don't exist, exploring the mathematical properties of these solutions helps us understand black holes better.”

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