Universe Colloquium: Inferring past and present cosmic structures from observations

by Jens Jasche (TUM)

Wednesday 17 Dec 2014, 16:30 → 17:30 Europe/Berlin

seminar room (Excellence Cluster Universe, Boltzmannstrasse 2, Garching)

Current and future cosmological surveys produce huge amounts of data. An efficient and accurate information processing technology is needed to analyse and interpret this data. Besides traditional systematics and uncertainties modern data analysis needs to account for the complex statistical properties of gravitationally evolved matter fields. It also has to provide corresponding uncertainty quantification. The analysis of the structure and evolution of our inhomogeneous Universe hence requires to solve non-linear statistical inference problems in very high dimensional parameter spaces. This talk addresses the problem of high dimensional Bayesian inference from cosmological data sets via the recently proposed BORG algorithm. Its method couples an approximate model of structure formation to an Hybrid Monte Carlo algorithm. This provides a fully probabilistic, physical model of the non-linearly evolved density field as probed by galaxy surveys. Besides highly accurate and detailed measurements of 3D cosmic density and velocity fields, this methodology also infers plausible formation histories for the observed large scale structure. Jens will give an overview over this promising path towards Bayesian chrono-cosmography, the subject of inferring the four dimensional state of our Universe from observations. Jens Jasche is a new Cluster Research Fellow who started recently. The Universe Colloquium is followed by a social gathering with wine and cheese.