Probability of the most massive cluster under non-Gaussian initial conditions

TL;DR

This paper calculates the probability of observing the most massive high-redshift galaxy cluster under non-Gaussian initial conditions, providing a new way to test cosmological models and non-Gaussianity on small scales.

Contribution

It introduces a method to evaluate the likelihood of massive clusters under non-Gaussian initial conditions, extending constraints beyond traditional CMB and halo bias data.

Findings

Probability of massive clusters constrains non-Gaussianity on small scales.

Clusters can test for running of the non-Gaussianity parameter f_NL.

Results are consistent with Lambda CDM under non-Gaussian initial conditions.

Abstract

Very massive high redshift clusters can be used to constrain and test the Lambda CDM model. Taking into account the observational constraints of Jee et al. (2009) we have calculated the probability for the most massive cluster to be found in the range (5.2-7.6)e14 M_sun, between redshifts 1.4-2.2, with a sky area of 11 sqdeg and under non-Gaussian initial conditions. Clusters constrain the non-Gaussianity on smaller scales than current cosmic microwave background or halo bias data and so can be used to test for running of the non-Gaussianity parameter f_NL.