The Mass Function of Void Groups as a Probe of the Primordial non-Gaussianity

TL;DR

This paper develops an analytic model for the mass function of void galaxy groups to use their abundance as a sensitive probe of primordial non-Gaussianity, aiding in understanding cosmic inflation.

Contribution

It introduces a novel analytic framework for void group mass functions incorporating non-Gaussian initial conditions, tested against observational data.

Findings

The model effectively fits SDSS data on void groups.

Void group abundance shows sensitivity to primordial non-Gaussianity.

Potential to distinguish inflation models through void group statistics.

Abstract

The primordial non-Gaussianity signal, if measured accurately, will allow us to distinguish between different candidate models for the cosmic inflation. Since the galaxy groups located in void regions are rare events, their abundance may be a sensitive probe of the primordial non-Gaussianity. We construct an analytic model for the mass function of void groups in the framework of the extended Press-Schechter theory with non-Gaussian initial conditions and investigate how it depends on the primordial non-Gaussianity parameter. A feasibility study is conducted by fitting the analytic mass function of void groups to the observational results from the galaxy group catalog of the Sloan Digital Sky Survey Data Release 4 with adjusting the primordial non-Gaussianity parameter.