The aim of the ERC research group Theoretical Cosmology is to enhance our understanding of the very early universe and its most mysterious aspect, the big bang. The research group was established in 2010 with the support of a Starting Grant from the European Research Council, and is currently funded by the ERC and the Max Planck Society.
It seems likely that a great many features of our universe were determined by the physical processes taking place around the time of the big bang, as the initial conditions for the future evolution of the universe were set at that time. Moreover, we already know that these initial conditions must have been rather special: extrapolating back from current observations, it is clear that the universe must have been exceptionally flat, homogeneous and isotropic at these early times, but at the same time small density fluctuations (with a nearly scale-invariant spectrum) were needed in order to provide seeds for the formation of the large-scale structures via subsequent gravitational collapse.
There currently exists no complete theory that satisfactorily explains these “initial” conditions. However, there are promising candidate theories, such as inflationary cosmology and the theory of the cyclic universe, among others. We study and develop these cosmological theories while trying to figure out their relationship with fundamental physics (such as supergravity and string theory). The big questions guiding our research are: what was the origin of the universe? What happened at the big bang, and was the big bang really the beginning? How did space and time emerge? And how did space and time come to behave so classically, given that our most fundamental laws are quantum mechanical laws? Is our universe unique? How much of the universe is predetermined and fixed by mathematical consistency requirements, and how much is historical accident? What is the fate of the universe in the far future? Is our universe a one-off event, or does it regenerate itself by having cycles of evolution? It is clear that progress in this field will have a strong impact, both on science and on the perception that we humans have of our place in the universe.