Bayesian optimal reconstruction of the primordial power spectrum

Understand

The form of the primordial power spectrum has the potential to differentiate strongly between competing models of perturbation generation in the early universe and so is of considerable importance.

• The recent release of five years of WMAP observations have confirmed the general picture of the primordial power spectrum as deviating slightly from scale invariance with a spectral tilt parameter of n_s ~ 0.96.
• Nonetheless, many attempts have been made to isolate further features such as breaks and cutoffs using a variety of methods, some employing more than ~ 10 varying parameters.
• In this paper we apply the robust technique of Bayesian model selection to reconstruct the optimal degree of structure in the spectrum.