Using simulations to understand disruption of space-time
As a new Professor of Gravitational Theory at Friedrich Schiller University in Jena, Sebastiano Bernuzzi calculates and simulates collisions between black holes or neutron stars. Thereby, he contributes to the detection of gravitational waves.
It has been over a century since Albert Einstein predicted the existence of gravitational waves, which disrupt space-time, ‘rippling’ through our universe at the speed of light. The waves are caused by the acceleration of any object, but their vibrations are so incredibly weak that evidence can only be obtained from catastrophic events such as colliding neutron stars or supernova explosions. It is less than four years since researchers succeeded in detecting gravitational waves that had resulted from a collision between two black holes. This proof was hailed as a milestone in the history of astrophysics.
Scientists at Friedrich Schiller University in Jena were also involved in the preparatory work for this breakthrough. This team is now being strengthened by the arrival of Prof. Sebastiano Bernuzzi. The 37-year-old astrophysicist from Italy is now Professor of Gravitational Theory in Jena.
Supercomputers calculate models of stellar collisions
“With the help of Einstein’s general theory of relativity, we are developing simulations that describe collisions between neutron stars light years from Earth,” explains Bernuzzi. “Our calculations are very complex, as in addition to gravitation, we also have to take into account other forces such as electromagnetism or nuclear forces.” In order to create a precise simulation from all these factors, Bernuzzi uses the power of superfast computer systems. The importance of his research is evidenced by the funding that Bernuzzi is receiving through the European Research Council. Since 2017, he has been supported by an ‘ERC Starting Grant’, which is only awarded to promising young researchers.
The results of Bernuzzi’s simulations also serve the practical detection of gravitational waves. To this end he is cooperating with, among others, researchers at the European gravitational wave detector ‘Virgo’ – a kilometre-long instrument that uses laser beams to detect displacements in the subatomic range. “Applying our predictions resembles the filtering of sounds through the human brain,” says Bernuzzi. “If we know the song of a particular bird, we are able to recognise it even amongst louder sound sources.”
“Jena is the best environment for me”
Sebastiano Bernuzzi has known for some time that the University of Jena offers excellent conditions for him to optimise his models further. After obtaining his PhD in his home city of Parma in 2009, he did postdoctoral research at the Institute for Theoretical Physics in Jena for four years. “It was a very enjoyable and intensive time for me, in which I developed further as a scientist,” Bernuzzi recalls. He then spent a period doing research at the elite Caltech Institute of Technology in Pasadena, California, and – back in Parma – he obtained his post-doctoral qualification in 2017. “Then, when the possibility arose of returning to Jena, I did not hesitate,” added Bernuzzi, a father of two. “Due to its clear emphasis on theoretical physics, Jena is the best environment for me, for making progress in my research and my career.”
Neutron stars as possible source of heavy elements
In the near future, he wants to study in particular the components of the emissions left by the collision of binary neutron stars. “The emissions have hardly been studied as yet and they probably provide an explanation for the development of heavy elements,” explains Bernuzzi. “We probably have the fusion of these extremely compact objects to thank for the fact that we wear gold rings.” Another research objective of his is to gain a better understanding of the fundamental physical processes that underlie these phenomena. “The collisions represent unique laboratories, which we cannot recreate on Earth. The basic knowledge that we obtain through studying them will be useful over the medium term to many areas of applied science, and by extension also to society.”
Prof. Sebastiano Bernuzzi
Institute for Theoretical Physics of Friedrich Schiller University, Jena
07743 Jena, Germany
Tel.: +49 (0)3641 / 947111