Features and nongaussianity in the inflationary power spectrum

I summarize recent work on (1) constraining spike-like features in the cosmic microwave background and large scale structure; (2) nonstandard Friedmann equation in stabilized warped 6D brane cosmology, with applications to inflation; and (3) nonlocal inflation models, motivated by string theory, which can yield large nongaussian CMB fluctuations. Work in collaboration with N. Barnaby, T. Biswas, F. Chen, L. Hoi, G. Holder and S. Kanno.