Inflation in the post-Planck era
According to our current ideas, structure in the universe was seeded by quantum fluctuations which were classicalized during an early inflationary era. Later these seeds collapsed under gravity to generate the hot- and cold-spots in the cosmic microwave background, and the high- and low-points in the galaxy distribution. Assuming this picture to be correct, the key to learning more about the underlying microphysics is to determine the statistical properties of the underlying seed fluctuations.
We now understand in considerable detail how to do this for the microwave background. Most of the information this contains has now been extracted, so to go further we must find more observables which inherit their statistical properties from the primordial seeds. A global effort is now underway to understand how large surveys of cosmic structures can be used for this purpose. The Sussex group is involved in this effort and PhD projects are available covering a number of topics. These include: (1) accurate prediction of large-scale structure observables from inflationary models, (2) finding ways to compare inflationary models to observations, (3) how to combine search for best-fit inflationary models given a combination of cosmological datasets.
Projects in this area typically requires a mix of analytical and numerical work. A background in relativity, cosmology and quantum field theory is helpful.