University of Edinburgh
Particle Cosmology
A. Berera
The study of the early Universe is now becoming a mature interdisciplinary subject, driven by the development of SUSY- and string-motivated models for inflation on the particle side, and by major new computational and observational developments on the astronomy side. Our work concentrates on the early phases of the Big Bang, primarily with interest with interest in inflationary cosmology, string cosmology and cosmic magnetic fields.
One of our specific areas of focus is in developing the warm inflation dynamics. This is an alternative solution to the cosmological puzzles, in which aspects of thermal and non-equilibrium field theory are employed, and this differs from the present-day conventional inflation model. Specifically, in conventional `supercooled' inflation, the Universe is assumed to undergo a supercooled quasi-exponential expansion that terminates with a short reheating period; this sets an appropriately high temperature to allow subsequent hot Big-Bang evolution. In contrast, warm inflation does not involve any artificial division between supercooled expansion and reheating: radiation is produced throughout inflationary expansion and reheating is non-existent. Our work on warm inflation cosmology continues to follow three directions: quantum field theory (QFT) dissipative dynamics that realise first-principles warm inflation models; observational consequences of warm inflation, in particular scalar and tensor perturbation spectra; consequences of warm inflation for the particle physics cosmology of baryogenesis, defects, and vacuum energy. In addressing these topics, various areas of particle physics are untilized including nonequilibrium quantum field theory, supersymmetry, and gauge theory.
Applications of quantum field theory
We are interested in applications of statistical field theory methods to the turbulence problem. This includes both theoretical analytic work as well as high-resolution numerical simulations of the Navier-Stokes equation. We are also interested in the conseqences of turbulence in the Universe to the evolution of cosmic magnetic fields.