Structure Formation in the Symmetron Model

TL;DR

This paper investigates how the symmetron scalar field influences cosmic structure formation, revealing observable effects on matter distribution and halo formation through N-body simulations, and confirms the effectiveness of the screening mechanism.

Contribution

It provides the first detailed N-body simulation analysis of structure formation in the symmetron model, demonstrating its observable signatures and screening efficiency.

Findings

Significant modifications in the linear matter power spectrum.

Alterations in the nonlinear matter power spectrum.

Changes in the halo mass function.

Abstract

Scalar fields, strongly coupled to matter, can be present in nature and still be invisible to local experiments if they are subject to a screening mechanism. The symmetron is one such mechanism which relies on restoration of a spontaneously broken symmetry in regions of high density to shield the scalar fifth force. We have investigated structure formation in the symmetron model by using N-body simulations and find strong observable signatures in both the linear and nonlinear matter power spectrum and on the halo mass function. The mechanism for suppressing the scalar fifth force in high density regions is also found to work very well.