Precision tests of dark sector (PreCoG)

Modern cosmology assumes that General Relativity (GR) correctly describes gravity at the scales of galaxies, clusters and the observable universe. With this assumption, and according to observations, the cosmological model must include not only dark matter (25% of the energy budget), but also dark energy (DE, 70% of the energy budget). While these dark components have been extensively studied and constrained with data, significant tensions in the standard cosmological model remain. One tantalising possibility is that these tensions are evidence that gravity on the scales of the universe is governed by a different theory to GR (modified gravity, MG). In this project, we will develop analytic and numerical tools to allow observations of gravitational waves (GW) to be used fully to discover the mechanism behind DE. Aims: 1) determine the emission of GW from compact objects in MG models which can be responsible for cosmic acceleration; 2) determine how GW propagate in MG in the realistic universe; 3) find methods of translating constraints on MG from GW signals to constraints on gravity on cosmological scales