Current cosmological observations are remarkably consistent with a concordance cosmology including an epoch of inflation in the very early universe. There is a tantalizing possibility that the ultra-high energy physics of the very early universe could be deduced from cosmological observations. In particular, the observed angular power spectrum of the CMB anisotropy is a convolution of the cosmological radiative transport kernel with the power spectrum of primordial perturbations. Exquisite

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... rements of the angular power spectrum over a wide range of multipoles from WMAP have opened up the possibility to deconvolve the primordial power spectrum for a given set of cosmological parameters. We present an update on our ongoing research program to recover the primordial power spectrum from CMB anisotropy. The robust features in the recovered primordial spectrum could be signatures of the physics behind inflation. Initial work towards mapping out the likelihood, 'optimized' over the unknown primordial spectrum, in the space the cosmological parameters reveal interesting results. Increasingly accurate measurements of the anisotropy in the temperature of the cosmic microwave background (CMB) have ushered in an era of precision cosmology. A golden decade of CMB anisotropy measurements by numerous experiments was topped by the results from the data obtained by the Wilkinson Microwave Anisotropy Probe (WMAP). 1), 2) Under simple hypotheses for the spectrum of primordial perturbations, exquisite estimates of the cosmological parameters have been obtained from the angular power spectrum measurement by WMAP data combined with other cosmological observations. Precision measurements of anisotropies in the cosmic microwave background, and also of the clustering of large scale structure, suggest that the primordial density perturbation is dominantly adiabatic and has a nearly scale invariant spectrum. This is in good agreement with most simple inflationary scenarios which predict power law or scale invariant forms of the primordial perturbation. 3) The data have also been used widely to put constraints on different parametric forms of primordial spectrum, mostly motivated by inflation. 4) However, despite the strong theoretical appeal and simplicity of a featureless primordial spectrum, it is important to determine the shape of the primordial power spectrum directly from observations with minimal theoretical bias. Many model independent searches have been made to look for features in the CMB primordial power spectrum. 5) Accurate measurements of the angular power spectrum over a wide range of multipoles by WMAP have opened up the possibility of deconvolving the primordial power spectrum for a given set of cosmological parameters. 6) Theoretical motivations and models that give features in the power spectrum have also been studied and compared in post-WMAP literature. 7) The angular power spectrum, C , is a convolution of the primordial power spectrum P (k) generated in the early universe with a radiative transport kernel, G(l, k),