I study models that may shed light on the fundamental physics of the nature of dark matter, the origin of the baryon asymmetry, and the fundamental origin of inflation or other physics of the early universe. The goal is to use the clues contained in cosmological data to guide the construction of models of new physics. I am also interested in the role that cosmological data can play in constraining models of particle physics beyond the standard model. Such constraints can often provide complementary information about fundamental physics to that provided through terrestrial experiments such as those performed at colliders. My work within these areas has been broad, spanning approaches to dark energy and dark matter; extra dimensional models of particle physics and cosmology; the baryon asymmetry of the universe; inflation and its problems and alternatives; topological defects in cosmology; and the BPS structure of intersecting branes in supersymmetric theories. Specifically, my work has mapped out the space of viable models of the accelerating universe. This has included investigating the microphysical implications of exotic dark energy models, and proposing one of the most-studied approaches to the idea that a modification of general relativity may explain cosmic acceleration. ➤
