A. Frolov (Simon Fraser University)

Title:  Primordial Non-Gaussianity from Preheating

Abstract:  The idea of inflation (a period of rapid quasi-exponential expansion of the Universe) neatly solves several issues in cosmology. While the Universe is inflating, its contents is cold. Eventually, inflation ends and the field driving the inflation must decay, depositing energy into high-energy particles. This process, known as reheating, starts the hot big bang history as we know it. I will discuss a few scalar field models of reheating, which for all their simplicity have rich physics involving parametric resonance, non-linear evolution, and turbulence, and illustrate their dynamical behavior with simulations using a new numerical solver I developed. Most interestingly, preheating can create primordial non-Gaussian fluctuations at potentially observable levels, which could give a glimpse of physics at energies we know very little about.