The Effect of Primordial Anti-Biasing on the Local Measurement of the Key Cosmological Parameters

TL;DR

This paper demonstrates that the discrepancy between local galaxy cluster counts and Planck CMB measurements can be resolved by considering primordial anti-biasing, specifically the local universe being in a crest of the primordial potential.

Contribution

It introduces a primordial anti-biasing condition into cosmological models, reconciling local cluster observations with Planck data without altering the standard LambdaCDM framework.

Findings

Local universe in a primordial potential crest explains cluster count discrepancy.

Incorporating primordial potential conditions aligns local observations with Planck cosmology.

The standard LambdaCDM model remains consistent when primordial anti-biasing is considered.

Abstract

The best-fit values of the density parameter and the amplitude of the linear density power spectrum obtained from the Cosmic Microwave Background (CMB) temperature field scanned by the Planck satellite are found to notably disagree with those estimated from the abundance of galaxy clusters observed in the local universe. Basically, the observed cluster counts are significantly lower than the prediction of the standard flat LambdaCDM model with the key cosmological parameters set at the Planck best-fit values. We show that this inconsistency between the local and the early universe can be well resolved without failing the currently favored flat LambdaCDM cosmology if the local universe corresponds to a region embedded in a crest of the primordial gravitational potential field. Incorporating the condition of positive primordial potential into the theoretical prediction for the mass function of cluster halos, we show that the observed lower number densities of the galaxy clusters are in fact fully consistent with the Planck universe.