Physikalisches Kolloquium: Prof. Dr. Matthias Bartelmann – Universality and self-similarity of cosmic structures on small scales

Titel: Universality and self-similarity of cosmic structures on small scales

Abstract:
The Universe is observed to be richly structured on all scales, from its early days to the present. While we understand the evolution of large-scale structures whose density contrast is small, interesting questions arise on small scales where the density contrast grows large. In fact, small-scale cosmic structures are observed to be self-similar in the sense that the power spectrum of dark-matter density fluctuations falls off with wave number k like k⁻³ such that the fluctuation power approaches a constant for large k. Why is this so? Within the kinetic field theory of cosmic structure formation, it is possible to prove that this asymptotic behaviour is a necessary consequence for structures developing from a Gaussian random field in three dimensions under quite general conditions. This is confirmed by an asymptotic analysis of solutions of the Liouville equation. I will discuss this result, its derivation, and some of its implications.

Sprecher / Speaker: Prof. Dr. Matthias Bartelmann, Universität Heidelberg
Kontakt / Contact: Prof. Dr. Klaus Mecke