Relativity Theory’s Recondite Secrets

Professor Hans Ringström will receive funding from the Knut and Alice Wallenberg Foundation to recruit an international researcher for a postdoctoral position at the Department of Mathematics, KTH Royal Institute of Technology, Stockholm.

Even though Einstein’s general theory of relativity is over 100 years old, its notoriously difficult equations have not been fully solved. The need for deeper understanding of the equations has increased due to new astronomical discoveries over the last twenty years.

Towards the end of the 1990s, scientists were surprised to discover that the Universe appears to be expanding at an increasing rate. And, in September 2015, physicists made the first ever observation of gravitational waves from two colliding black holes. The existence of the waves had been predicted by the general theory of relativity. This discovery may revolutionize astronomy, providing scientists with a new window into the Universe, in addition to observations of light and other electromagnetic waves.

So far, physicists used highly symmetrical models of the universe to solve Einstein’s equations. Even studies of more limited systems, like that of an isolated planet, a galaxy, or a black hole, have assumed symmetry. In the 1970s, physicists developed new, geometric ways of analyzing these solutions. Stephen Hawking and others described singularities, in which gravity becomes infinite inside black holes or in the big bang, as probably being typical of Einstein’s equations.

However, these new descriptions were only qualitative and limited. Therefore, over the last 30 years, attention has turned to new ways of analyzing the equations using less stringent symmetry assumptions. This approach gives hope of creating a mathematical basis for better understanding Einstein’s theory of relativity and thus interpreting the ever-growing collection of cosmic observations.

Foto: Jann Lipka