John Peacock (IfA, University of Edinburgh)

Probing gravity with galaxy surveys - John Peacock Colloquium

ATNF Marsfield Lecture Theatre

Abstract

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.