My major research interest is in theoretical cosmology, with a specific interest in the study of cosmological perturbations.  In the standard big-bang framework of cosmology, a hot, dense, smooth universe begins in a rapidly expanding state.  As the universe continues to expand, the temperature becomes cooler, the material in the universe becomes less dense, and the expansion rate slows down.  As the universe cools, light elements can form (such as deuterium, helium-3 and helium-4, and lithium).  Eventually, it cools so much that neutral atoms can form (leaving a relic, decoupled photon background), and the expansion rate slows to that observed today.  These three observations, the light element abundances, the cosmic microwave radiation background, and the Hubble expansion of the universe, are the three cornerstones of big bang cosmology.  However, the universe is not perfectly smooth, it is full of stars, galaxies, and clusters.  The entire structure of the universe, then, must grow out of a universe which is mostly smooth, but not quite perfectly smooth.  These imperfections in the early universe are known as cosmological perturbations, and their creation, evolution, and impact on the universe are my primary fields of research.

Cosmological Perturbations: The discussion of cosmological perturbations allows us to ask a number of questions about their relation to the universe.  Some of these include:
My research has attempted to address some of these issues, and this is an ongoing project.  So far, we have found that growing cosmological perturbations create magnetic fields on all scales, that the gravitational inhomogeneities do impact the expansion rate, but the effect is small, and that in the presence of the right types of extra dimensions, the cosmological perturbations in gravitational radiation can have wildly different properties.  My Ph.D. dissertation is on the subject of these cosmological perturbations and their effects on the universe.  Additionally, a list of my publications is below:
My Curriculum Vitae

My publications at ADS and SPIRES