Testing model independent modified gravity with future large scale surveys

TL;DR

This paper investigates how including galaxy cluster data can enhance constraints on model-independent modified gravity parameters using future large-scale surveys and forecasts the potential improvements over current methods.

Contribution

It introduces the use of galaxy clusters in combination with CMB and weak lensing data to improve constraints on modified gravity parameters, highlighting their significance.

Findings

Cluster counts significantly improve constraints over CMB and WL alone.

Future surveys could further tighten constraints on modified gravity models.

Adding galaxy clusters enhances the potential of cosmological tests of gravity.

Abstract

Model-independent parametrisations of modified gravity have attracted a lot of attention over the past few years and numerous combinations of experiments and observables have been suggested to constrain the parameters used in these models. Galaxy clusters have been mentioned, but not looked at as extensively in the literature as some other probes. Here we look at adding galaxy clusters into the mix of observables and examine how they could improve the constraints on the modified gravity parameters. In particular, we forecast the constraints from combining Planck satellite Cosmic Microwave Background (CMB) measurements and Sunyaev-Zeldovich (SZ) cluster catalogue with a DES-like weak lensing survey. We find that cluster counts significantly improve the constraints over those derived using CMB and WL. We then look at surveys further into the future, to see how much better it may be feasible to make the constraints.