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If you asked any astronomer what has yet to be discovered in the universe, there’s a good chance they would paraphrase Donald Rumsfeld: It is full of known unknowns.
In addition to the regular matter and energy that we know and love, the universe is also made up of two big mysteries: dark energy and dark matter. Theoretical astrophysicists aim to tackle these unknowns by mathematically dreaming up objects that can address the gaps in our knowledge. Thus, in research published In classical and quantum gravity, a team of astrophysicists have proposed an alien type of object called “Nystar” as a solution to a blind spot in Einstein’s general theory of relativity.
Nestor is similar to Gravastar, short for gravitational vacuum condensate star. Gravstar is a theoretical object Proposed in the early 2000s Its outer part is made of extremely thin material and a core made of dark energy,
Like Gravstar, Nestor is an extreme theoretical object, but with a twist. In their work, researchers Daniel Jampolsky and Luciano Rizzola have proposed that gravity stars could be nested—hence, “nestars—and “extended to an arbitrarily large number of shells,” they write, generating such an object. Which “provides a new solution to Einstein’s equations.”
“Nestar is like a Matryoshka doll,” said Jampolsky, a researcher at the Institute for Theoretical Physics at Goethe University Frankfurt am Main in Frankfurt. release, “Our solution to the field equations allows for a whole range of nested gravity stars.”
Einstein formulated his equations a century ago; In the intervening decades, discoveries by other researchers disproved them. In 1916 he predicted the existence of black holesAnd in 1971, a Black hole identified for the first time. But at the center of a black hole, general relativity breaks down. At the center of these objects, gravity is so strong that even light cannot escape them, a point where time slows down and space is compressed to a point of infinite density.
Enter gravastars: almost as compact as black holes, with similar gravitational forces on their surfaces. However, gravastars lack an event horizon – meaning that external observers can obtain information from them – and do not have a singularity at their core. Rather, their (again, theoretical) cores are composed of dark energy, which counteracts the enormous gravitational force pulling matter inward toward the core.
Exact solutions to Einstein’s field equations have been found before in the general theory of relativity; In fact, the first discovery was made by Karl Schwarzschild in the same year that Einstein introduced the theory. Nestors offer a new solution to an old problem… if they exist, of course.
“It is great that even 100 years after Schwarzschild presented his first solutions to Einstein’s field equations from the general theory of relativity, it is still possible to find new solutions,” Rizzola, a theoretical astrophysicist at Goethe University, said in the same release. Said. “It’s like finding a gold coin on a path that many others have explored before.”
“Unfortunately, we still don’t know how such a gravastar could be created,” Rizzola said. “But even if Nestor does not exist, exploring the mathematical properties of these solutions ultimately helps us better understand black holes.”
More: A black hole star may be the tripciest object in space
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