Biased cosmological parameter estimation with galaxy cluster counts in the presence of primordial non-Gaussianities

Understand

The redshift dependence of the abundance of galaxy clusters is very sensitive to the statistical properties of primordial density perturbations.

• It can thus be used to probe small deviations from Gaussian initial conditions.
• Such deviations constitute a very important signature of many inflationary scenarios, and are thus expected to provide crucial information on physical processes which took place in the very early Universe.
• We have determined the biases which may be introduced in the estimation of cosmological parameters by wrongly assuming the absence of primordial non-Gaussianities.