Onsdagskollokvium (NB note the day and time): Ruth Durrer: The large scale matter distribution of the Universe
Ruth Durrer, Professor, University of Geneva
In the last 20 years, observations of the cosmic microwave background (CMB) have revolutionized cosmology from an order of magnitude science to 'precision cosmology'. We would like to repeat this success story with observations of large scale structure (LSS) by deep galaxy surveys. The advantage of such surveys is that they are 3-dimensional and therefore contain more information than the 2-dimensional CMB.The disadvantage is that the relation between the galaxy distribution and LSS is obscured by the problem of biasing.
In my talk I shall explain that the standard 3d LSS power spectrum is not really observable and that we should instead present our results in terms of a redshift dependent angular power spectrum, C_l(z,z'). This observable also contains redshift space distortions, lensing effects and other relativistic contributions which I shall discuss. I shall then comment on recent Fisher matrix forecasts which we have derived using this variable for surveys like 'Euclid' and I shall briefly describe how we have incorporated its calculation in a publicly available code called 'CLASSgal'.