Beyond Einstein: Cosmological Tests of Model Independent Modified Gravity

TL;DR

This paper investigates how including galaxy cluster data can enhance constraints on model-independent modified gravity theories by combining CMB, SZ cluster catalogues, and weak lensing surveys.

Contribution

It introduces galaxy clusters as an additional probe to improve constraints on modified gravity parameters in a model-independent framework.

Findings

Adding cluster counts improves constraints on modified gravity.

Combining CMB, SZ, and weak lensing data yields tighter bounds.

Galaxy clusters are a valuable addition to cosmological tests of gravity.

Abstract

Model-independent parametrisations of modified gravity have attracted a lot of attention over the past few years; numerous combinations of experiments and observables have been suggested to constrain these parameterisations, and future surveys look very promising. 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 whether they could improve the constraints on the modified gravity parameters. In particular, we forecast the constraints from combining the Planck CMB spectrum and SZ cluster catalogue and a DES-like Weak Lensing survey. We've found that adding cluster counts improves the constraints obtained from combining CMB and WL data.