Modifications of Gravity and Early Universe Cosmology

In order to make predictions which can be tested with experiments, mathematical models describing the universe it its early stages require the use of cosmological perturbation theory. In this research the student will initially study a specific theory of gravity, determine the predictions of the power spectrum of linear perturbations produced during a phase of inflation in the early universe. The statistical properties of the perturbations are also studied. The aim is to check whether large non-Gaussianities can also imply that the power spectrum to be no longer of power-law form. In subsequent work, f(R) theories of gravity of the early universe are investigated. The work will consist of both analytical work (cosmological perturbation theory in particular) and numerical work.