Early Universe Cosmology
S. Shankaranarayanan

We are in the golden era of cosmology. Starting from COBE (COsmic Background Explorer), over the last two decades, we have acquired a wealth of new information about the origins of our universe by precise astrophysical and cosmological observations. Observations by WMAP (Wilkinson Microwave Anisotropy Probe) are much more accurate and help in identifying right model of the early universe. The recent PLANCK data has 5 orders higher accuracy compared to WMAP.

Here we plan to analyse the observed pattern of anisotropies in the Cosmic Microwave Background to place tight constraints on the cosmological parameters including the primordial perturbations. Such analyses invariably require one to maximize the likelihood function with respect to changes in several parameters, which requires inverting the data covariance matrix at every step.