Probing Fundamental Physics with Cosmology

New precision Astronomical observations have spurred the development of a ?concordance? cosmological model, based on inflation and having three components to the energy present in the universe: ordinary matter, dark matter, and dark energy. The model is constrained by a variety of high-quality, independent measurements such as large-scale structure, the Cosmic Microwave Background (CMB), gravitational lensing, the primordial abundances of light elements, and Type-IA Supernovae used as standard candles. The objective of the proposed research is to develop and apply theoretical techniques that use cosmological observations to constrain the physics of the early universe, focusing specifically on the successful paradigm of inflation. Inflation?s basic predictions of Gaussian, adiabatic, nearly scale-invariant cosmological perturbations have been beautifully confirmed by recent data, in particular the WMAP 3-year data set. Upcoming observations have the potential to provide data accurate enough to test inflation beyond a simple lowest-order description. This proposal focuses on four possible signals of new physics which might be detected in future data: Features in the density power spectrum, Primordial gravitational waves, primordial non-Gaussianity and Isocurvature fluctuations.The proposed research is designed to make detailed and quantitative connections between observational data and several properties of inflationary models. Based on high-precision cosmological data one hopes to answer fundamental questions such as the origin of the universe, the unification of gravitation with quantum mechanics, and the quantum-mechanical nature of the vacuum. The proposed project will have significant opportunities for participation by graduate and undergraduate students. There is wide public interest in cosmology. The PI intends to give public lectures on Cosmology at university and community events.