This proposal will explore how one can find a natural way to embed a period of cosmological inflation within recently proposed string theory compactification mechanisms. The first part of the research will consider a version of modular inflation called racetrack inflation developed by the PI and his collaborators. Modular inflation uses the potentials generated for the moduli fields that occur in string theory compactifications as the source of the negative pressure required for the inflationary period. In this picture the mechanism for reheating will be studied and the generation of fluctuations in the Cosmic Microwave background due to iso-curvature perturbations. The PI will also investigate other typed of inflation that can occur in string theory compactifications. The second aspect of the proposal will be a detailed study of D-Brane inflation. In this picture the scalar field responsible for inflation parameterizes the position of a brane along the internal manifold. One possible consequence of this picture is that during inflation there is brane-antibrane annihilation which could lead to the production of cosmic strings which have observable cosmological effects. The broader implications of this proposal are that If string theory can be directly verified (or falsified) by measurement of cosmological parameters this would be very important. The PI intends to create a web page for the general public explaining the main results of his work. He also intends to get involved with Physics Theory-Net and give lectures at local high schools.