Cosmic structure formation in massive conformal gravity

TL;DR

This paper investigates how massive conformal gravity influences the growth of cosmic structures, revealing it enhances early universe formation but suppresses it at later times compared to the standard Lambda-CDM model.

Contribution

It derives the linear growth equation for matter perturbations within massive conformal gravity, providing new insights into structure formation beyond standard cosmology.

Findings

MCG enhances structure formation at high redshifts

MCG suppresses structure formation at low redshifts

Growth behavior differs from Lambda-CDM model

Abstract

We study the evolution of matter density perturbations in the framework of massive conformal gravity (MCG). Starting from the conservation of the energy-momentum tensor, we find the continuity and Euler equations for the conformal perfect fluid that fills the MCG universe. We then obtain the perturbed MCG cosmological equations, from which we derive the equation that determines the linear growth of matter fluctuations in the MCG universe. The resulting growth equation shows that MCG enhances cosmic structure formation at high redshifts and suppresses it at low redshifts when compared to the $\Lambda$CDM cosmological model.