03. 01. 2019

A group of four Czech scientists from the Faculty of Mathematics and Physics of the Charles University and from the Institute of Mathematics of the CAS has managed to discover a solution of the so-called quadratic gravity describing a new type of spherical black hole. The research, drawing on numerical simulations by an international team of scientists, has been published in the prestigious journal Physical Review Letters.

“In 2016, we have discovered a new mathematical approach to the problem of spherical black holes. This enabled us to simplify the equations in a fundamental way. We can speak of a mathematical breakthrough: in the past, the equations could be studied mainly by numerical methods in the computers because of their complexity, but now they can be studied with just a pencil and paper, which brings about a qualitative leap in the formulation of the problem. Now we have been able to solve even these equations,” said Vojtěch Pravda from the Institute of Mathematics of the CAS. The other three scientists participating in the research were Alena Pravdová (also from the Institute of Mathematics), Jiří Podolský and Robert Švarc (from the Faculty of Mathematics and Physics).

The team has managed to find a mathematical solution which describes a new black hole. While the universally known Schwarzschild black hole is characterized only by its mass, this new black hole is also characterized by the value of the Bach invariant on the horizon. The team of Czech researchers has found out that its value influences, for example, the movement of objects orbiting this hypothetical black hole, thus creating potentially measurable deviations from classic Einstein gravity.

Black holes in general present a crucial theoretical laboratory for research of classic as well as quantum aspects of gravity, such as their evaporation in the form of Hawking radiation, and the corresponding thermodynamic properties. In the case of the newly discovered type of black hole we can expect a contribution toward a better understanding of various aspects of quadratic corrections of Einstein’s theory and their role in the full theory of quantum gravity.

The abovementioned research follows up on recent simulations by scientists from the United Kingdom, USA, and China which have pointed to the possibility of existence of this black hole. The results of the Czech research are now gradually published in a series of works. One of them was published in December 2018 in the prestigious journal Physical Review Letters published by the American Physical Society (APS). Further information including the abstract is available here.

Prepared by: Department of Media Communication of the Head Office of the CAS in cooperation with the Institute of Mathematics of the CAS
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