Non-linear relativistic effects on cosmological perturbations

The growth of cosmological perturbations is usually studied either through perturbation theory or via non-linear simulations. In the former approach, the full effects of general relativity are included, but the calculations are limited to large scales where the perturbations are small. Conversely, simulations are able to follow the evolution on small scales, but the treatment of gravity is usually approximated as Newtonian. The focus of this project is to understand how a fully relativistic treatment affects the non-linear evolution of structure, and how this will impact our interpretation of the next generation of large scale structure data, such as the Square Kilometre Array (SKA).

The student will be building our recent advances in this area, including a consistent second order relativistic code and our understanding of how Newtonian simulations can be interpreted in a relativistic context. They will also work to determine how line-of sight effects, like gravitational lensing, can impact the observations on the largest scales.