Research

Gravitational waves (GWs) produced by sources from the early Universe, if detected, would provide novel insights into high-energy phenomenology, complimentary to the groundbreaking discoveries made in the E&M spectrum using the CMB. Measurements of this primordial gravitational wave background will be most useful to our theoretical understanding of the early Universe if we have developed comprehensive models of their characteristic spectra before they are discovered. In this project, we will develop a new version of the fully-relativistic AMR evolver GRChombo, which uses the CCZ4 decomposition to evolve the spacetime metric in the presence of compact objects. This new version will be capable of generating highly-accurate templates for gravitational wave signals produced by early-Universe phenomena. This program will be used to produce expected GW spectra from highly-nonlinear sources, such as the transition out of the inflation area and the evolution of cosmic strings, whose shape and amplitudes can then be characterised. We can then extend this work to study spectra produced by quantum tensor modes of the gravitational field in this regime, and examine the feasibility of using primordial GWs to distinguish various models of inflation.