A sabbatical in Germany gave Håkan Andréasson the opportunity to delve deeper into Einstein’s highly complex equations. By the time he returned to Gothenburg, he and his colleagues had made some headway.
Professor of Mathematics Håkan Andréasson took a two-month sabbatical in Germany during 2015. To successfully combine this trip with his home life, he decided to divide his stay into two parts, with one half in the spring and one in the autumn. He spent one month at the University of Cologne in March, and another at the University of Bayreuth in October. Andréasson already had well-established collaborations and on-going projects with researchers at both these universities. His sabbatical gave him the opportunity to further develop these partnerships.
“Ordinarily, we meet for one week at a time, which feels kind of short. To make progress, we need to be able to bounce different ideas around, which requires cooperation and also time, given that testing various mathematical ideas is quite time-consuming. If you only have a week, you can only test a handful of methods,” he explains.
Andréasson’s research focuses on Einstein’s equations. “These are very complicated equations that we’re looking to solve.”
More specifically, he and his colleague in Cologne worked on the stability of solutions that describe galaxies. For these solutions to occur in nature, they must be stable. To date, no one has successfully demonstrated stability in stationary solutions to Einstein’s equations. During his visit to the University of Bayreuth, Andréasson worked on a well-known cosmic censorship hypothesis formulated by Roger Penrose and Stephen Hawking in the 1970s.
There are clear links between Andréasson’s research and what is expected to be the discovery of the century: gravitational waves. Gravitational waves are traces of the most violent events in the history of the universe, the discovery of which was announced in February of this year. Researchers in Louisiana, USA, have successfully detected signals given off by gravitational waves, confirming Einstein’s theories. These waves represent solutions to Einstein’s equations. Until now, astronomers have only been able to detect electromagnetic waves, such as light and radio waves, but this discovery may herald the dawn of a new age for space observation.
“It’s a truly audacious discovery. The discovery of gravitational waves gives us the opportunity to create a new type of telescope that reveals information about the universe that wasn’t previously obtainable,” Andréasson explains.
The collaborating researchers are currently working on the equations individually, and one of Andréasson’s German colleagues recently visited Gothenburg. “We made progress in our research when I was in Germany that I believe would have been difficult to achieve operating under an ordinary work schedule, where you’re more likely to be interrupted by the need to care for administrative tasks, meetings with students and other commitments,” Andréasson concludes.
Since 2013, the Faculty of Science has had a sabbatical programme for permanently-employed
teaching staff and researchers. The focus is on development and renewal of research efforts.
Financial support is awarded to allow full-time research for up to six months on any topic the
researcher prefers and in an international environment.