The effects of primordial non-Gaussianity on the cosmological reionization

Understand

We investigate the effects of non-Gaussianity in the primordial density field on the reionization history.

• We rely on a semi-analytic method to describe the processes acting on the intergalactic medium (IGM), relating the distribution of the ionizing sources to that of dark matter haloes.
• Extending previous work in the literature, we consider models in which the primordial non-Gaussianity is measured by the dimensionless non-linearity parameter f_NL, using the constraints recently obtained from cosmic microwave background data.
• We predict the ionized fraction and the optical depth at different cosmological epochs assuming two different kinds of non-Gaussianity, characterized by a scale-independent and a scale-dependent f_NL and comparing the results to those for the standard Gaussian scenario.