Unveiling the singular dynamics of the cosmic large-scale structure

by Cornelius Rampf

Wednesday 25 Sept 2019, 11:30 → 13:30 Europe/Zurich

4/2-011 - TH common room (CERN)

 Cosmic structures in the Universe result from a battle Royale involving two of nature's greatest unknowns, namely dark energy that is a repulsive force, and cold dark matter (CDM) that clusters gravitationally. Eventually, the CDM trajectories begin to intersect ("shell-crossing"), which marks the starting point of complex computations in the phase-space on the one side, and the birth of our cluttered Universe on the other side. I show that, due to the collision-less nature of CDM, phase-space trajectories exhibit weakly singular behaviour such as local non-differentiability of the particle acceleration. These singular features may be regulated by assuming a finite temperature for dark matter, which, to some extend, simplifies the numerical computation but complicates the theoretical modelling. Alternatively, singular features are naturally tamed in semiclassical, Schrödinger-like descriptions for the large-scale structure which I will discuss as well.