Seminar: Probing gravity with galaxy surveys

Prof John Peacock 

University of Edinburgh

Download the pdf poster.

Modifications of gravity are studied with growing interest in cosmology. A strong motivation comes from the puzzling existence of dark energy; since the existence of DE is only inferred from the Friedmann equation, it may be that DE does not exist, but that a different equation should apply.

A way to tell is to look for evidence of non-standard gravity on smaller scales, via the growth of large-scale structure. This can be measured via redshift-space distortions of clustering, and this talk shows new measurements using 160,000 redshifts from the GAMA survey. At the 10% level, the results from 6 different galaxy subsets are all consistent with the standard LCDM model. Future projects offering improved accuracy will be reviewed.