cosmology seminar: Daniel Grin, IAS

Title: New light on cosmic initial conditions and dark matter Abstract: Deviations from adiabaticity and Gaussianity in the early universe may shed light on the physics seeding primordial fluctuations. I will discuss statistical techniques to extract local-type non-Gaussianity in the presence of the full CMB transfer function. I will discuss CMB methods to probe isocurvature fluctuations between baryons and dark matter (undetectable in linear theory), as well as a new limit to this mode. Extremely light axionic dark matter (m<10^{-18}) is in theoretical vogue, and I will discuss ongoing work to search for such axions using large scale structure and the CMB. I will close with the results of a new telescope search for decaying relic axions.