Cluster Counts Tension : a Sign of Primordial Non-Gaussianity ?

TL;DR

This paper investigates whether primordial non-Gaussianity in dark matter density fluctuations can resolve the tension between observed galaxy cluster counts and predictions based on Gaussian assumptions, potentially indicating new physics.

Contribution

It explores the impact of relaxing Gaussianity assumptions on cluster count predictions to address existing observational discrepancies.

Findings

Non-Gaussianity could alleviate the cluster count tension

Primordial non-Gaussianity affects large-scale structure predictions

Potential indication of non-Gaussian features in early universe

Abstract

Evolution and abundance of the large-scale structures we observe today, such as clusters of galaxies, is sensitive to the statistical properties of dark matter primordial density fluctuations, which is assumed to follow a Gaussian probability distribution function. Within this assumption, a significant disagreement have been found between clusters counts made by Planck and their prediction when calibrated by CMB angular power spectrum. The purpose of this work is to relax the Gaussianty assumption and test if Non-Gaussianity in dark matter primordial density fluctuations, could alleviate the tension.