Test of cosmological models and implications on neutrino masses from studies with X-ray luminous galaxy clusters

by Prof. Hans Böhringer (Max-Planck-Institut für extraterrestrische Physik)

Tuesday 15 Mar 2016, 16:15 → 17:15 Europe/Berlin

Auditorium (MPI fuer Physik)

Galaxy clusters are sensitive probes of the large-scale structure of the matter density distribution of the Universe. X-ray observations provide currently the best means to detect and characterise galaxy clusters. Using a statistically complete sample of galaxy clusters detected in the ROSAT All-Sky X-ray Survey, we constrain cosmological parameters, specifically the matter density and the amplitude of the large-scale matter density fluctuations. A comparison of these results with the measurements of cosmic microwave background anisotropies with the Planck satellite show some tension, which implies a less pronounced fluctuation amplitude of nearby large-scale structure as compared to the predictions based on Planck and a pure LCDM model. Damping of fluctuations by neutrino Dark Matter provides a possible explanation for this discrepancy. We discuss the constraints on the neutrino mass from this finding and from other measurements of the nearby large-scale structure of the Universe.