Ellipticity correlations between galaxies, reconstructions of the cosmic density field, tidal shear correlations in the cosmic structure

• Applicant: Professor Dr. Björn Malte Schäfer
• Subject Area: Astrophysics and Astronomy
• Term: from 2012 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 216538304

Ellipticity correlations between galaxies which are caused by their coupled angular momenta are a fascinating research topic. On the theoretical side they touch our understanding of cosmic structure formation and the tidal forces in the cosmic large-scale structure, which induce angular momentum into protogalaxies, and on the practical side we require an understanding of these ellipticity correlations for our interpretation of the weak cosmic lensing effect, in particular for the estimation of cosmological parameters. In this proposal I would like to address two questions: How well do ellipticities trace the tidal shear field and how does the tidal shear correlation functions look like in the principal axis frame of the protohaloes, which is the only frame of physical relevance.

• DFG Programme: Research Grants