A star like a Matryoshka doll: New theory for gravastars

According to findings by physicists at Goethe University Frankfurt, a gravastar could look like a matryoshka doll. Image: Daniel Jampolski and Luciano Rezzolla, Goethe University Frankfurt

If gravitational condensate stars (or gravastars) actually existed, they would look similar to black holes to a distant observer. Two theoretical physicists at Goethe University Frankfurt have now found a new solution to Albert Einstein’s theory of general relativity, according to which gravitational stars could be structured like a Russian matryoshka doll, with one gravastar located inside another.

The interior of black holes remains a conundrum for science. In 1916, German physicist Karl Schwarzschild outlined a solution to Albert Einstein’s equations of general relativity, according to which the center of a black hole consists of a so-called singularity, a point at which space and time no longer exist. Here, the theory goes, all physical laws, including Einstein’s general theory of relativity, no longer apply; the principle of causality is suspended. This constitutes a great nuisance for science: after all, it means that no information can escape from a black hole beyond the so-called event horizon. This could be a reason why Schwarzschild’s solution did not attract much attention outside the theoretical realm for a long time – that is, until the first candidate for a black hole was discovered in 1971, followed by the discovery of the black hole in the center of our Milky Way in the 2000s, and finally the first image of a black hole, captured by the Event Horizon Telescope Collaboration in 2019.

In 2001, Pawel Mazur and Emil Mottola proposed a different solution to Einstein’s field equations that led to objects which they called gravitational condensate stars, or gravastars. Contrary to black holes, gravastars have several advantages from a theoretical astrophysics perspective. On the one hand, they are almost as compact as black holes and also exhibit a gravity at their surface that is essentially as strong as that of a black hole, hence resembling a black hole for all practical purposes. On the other hand, gravastars do not have an event horizon, that is, a boundary from within which no information can be sent out, and their core does not contain a singularity. Instead, the center of gravastars is made up of an exotic – dark – energy that exerts a negative pressure to the enormous gravitational force compressing the star. The surface of gravastars is represented by a wafer-thin skin of ordinary matter, the thickness of which approaches zero.

Theoretical physicists Daniel Jampolski and Prof. Luciano Rezzolla of Goethe University Frankfurt have now presented a solution to the field equations of general relativity that describes the existence of a gravastar inside another gravastar. They have given this hypothetical celestial object the name “nestar” (from the English “nested”).

Daniel Jampolski, who discovered the solution as part of his Bachelor’s thesis supervised by Luciano Rezzolla, says: “The nestar is like a matryoshka doll”, adding that, “our solution to the field equations allows for a whole series of nested gravastars.” Whereas Mazur and Mottola posit that the gravastar has a near infinite thin skin consisting of normal matter, the nestar’s matter-composed shell is somewhat thicker: “It’s a little easier to imagine that something like this could exist.”

Luciano Rezzolla, Professor of Theoretical Astrophysics at Goethe University, explains: “It’s great that even 100 years after Schwarzschild presented his first solution to Einstein’s field equations from the general theory of relativity, it’s still possible to find new solutions. It’s a bit like finding a gold coin along a path that has been explored by many others before. Unfortunately, we still have no idea how such a gravastar could be created. But even if nestars don’t exist, exploring the mathematical properties of these solutions ultimately helps us to better understand black holes”.

Wissenschaftliche Ansprechpartner:

Professor Luciano Rezzolla
Institute for Theoretical Physics
Goethe University Frankfurt
Phone: +49 (69) 798-47871
rezzolla@itp.uni-frankfurt.de
https://astro.uni-frankfurt.de/rezzolla/

Originalpublikation:

Daniel Jampolski, Luciano Rezzolla: Nested solutions of gravitational condensate stars. Classical Quantum Gravity (2024) https://doi.org/10.1088/1361-6382/ad2317

A star like a Matryoshka doll: New theory for gravastars

Media Contact

Dr. Markus Bernards Public Relations und Kommunikation
Goethe-Universität Frankfurt am Main

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

ispace and University of Leicester collaborate on lunar night survival technology

ispace, inc. (ispace), a global lunar exploration company, and the University of Leicester, have agreed to collaborate on approaches to lunar night survivability for future ispace lunar lander and rover…

Technique to analyze RNA structures in ultra-high definition

This is where the Nottingham team, led by Dr Aditi Borkar, Assistant Professor in Molecular Biochemistry & Biophysics in the School of Veterinary Medicine and Science, has achieved a transformative…

Iron could be key to less expensive, greener lithium-ion batteries

What if a common element rather than scarce, expensive ones was a key component in electric car batteries? A collaboration co-led by an Oregon State University chemistry researcher is hoping…

Partners & Sponsors