A new search for features in the primordial power spectrum

We develop a new approach towards a high-resolution non-parametric reconstruction of the primordial power spectrum using the Wilkinson Microwave Anisotropy Probe (WMAP) cosmic microwave background temperature anisotropies that we confront with Sloan Digital Sky Survey large-scale structure data in the range k ∼ 0.01-0.1 h Mpc -1 . We utilize the standard A cold dark matter cosmological model but we allow the baryon fraction to vary. In particular, for the concordance baryon fraction, we compare indications of a possible feature at k ∼ 0.05 h Mpc -1 in WMAP data with suggestions of similar features in large-scale structure surveys.