Cosmological Probes of Structure Growth and Tests of Gravity

TL;DR

This paper reviews how cosmological observations can test modifications to general relativity, focusing on structure growth and dark energy, to better understand cosmic acceleration.

Contribution

It provides an introductory overview of observational methods for testing modified gravity models in cosmology.

Findings

Cosmological observables can constrain gravity models.

Modified gravity offers alternative explanations for cosmic acceleration.

Observational limitations affect the testing of gravity theories.

Abstract

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic expansion. Understanding the nature of dark energy is one of the most appealing questions in achieving a self-consistent physical model at cosmological scales. Modification of general relativity could potentially provide a more natural and physical solution to the accelerated expansion. The growth of the cosmic structure is sensitive in constraining gravity models. In this paper, we aim to provide a concise introductory review of modified gravity models from an observational point of view. We will discuss various mainstream cosmological observables, and their potential advantages and limitations as probes of gravity models.