Spherical Collapse Approach for Non-standard Dark Matter Models and Enhanced Early Galaxy Formation in JWST

TL;DR

This paper uses the spherical collapse model to study how non-standard dark matter with different equations of state affects early galaxy formation, comparing to cold dark matter and considering recent JWST observations.

Contribution

It introduces a novel analysis of non-zero dark matter equations of state within the spherical collapse framework, linking these models to early galaxy formation enhancements observed by JWST.

Findings

Non-standard dark matter models alter collapse thresholds and virial overdensities.

Alternative models can lead to increased early structure formation.

Results suggest potential explanations for JWST's high-redshift galaxy observations.

Abstract

Using the spherical collapse approach, we investigate the impact of two alternative dark matter models, each characterized by distinct non-zero equations of state, one constant and the other time dependent on the nonlinear regime. Specifically, we compare these models to standard cold dark matter (CDM) by analyzing their influence on the linear density threshold for nonrelativistic component collapse and virial overdensity. Additionally, we explore the number count of collapsed objects, or dark matter halos, analogous to the number count of galaxy clusters. Finally, in light of recent discoveries by the James Webb Space Telescope (JWST), indicating the potential for more efficient early galaxy formation at higher redshifts, we investigate how alternative dark matter assumptions can enhance structure formation efficiency during the early universe.