Universe Colloquium: Constraints on gravity, dark energy, cluster astrophysics, and neutrino properties from galaxy clusters

by David Rapetti (Dark Cosmology Instit. Denmark)

Wednesday 25 Apr 2012, 16:30 → 18:00 Europe/Berlin

seminar room (basement) (Universe Cluster, Garching)

Using 238 cluster detections drawn from the ROSAT All-Sky Survey and X-ray follow-up observations from the Chandra X-ray Observatory and/or ROSAT for 94 of those clusters, we obtain tight constraints on cosmic growth and expansion, luminosity-mass and temperature-mass scaling relations and neutrino physics. David will describe the novel statistical framework employed to self-consistently and simultaneously constrain cosmology and observable-mass scaling relations accounting for survey biases, parameter covariances and systematic uncertainties. Allowing the dark energy equation of state and the linear growth index to take any constant values, no evidence for departures from the standard cosmological paradigm, General Relativity plus a cosmological constant and cold dark matter, was found. David will review in detail our results and highlight the power of X-ray cluster studies to constrain both astrophysics and cosmology.