Cluster Constraints on f(R) Gravity

TL;DR

This paper uses galaxy cluster data combined with other cosmological observations to place stringent constraints on f(R) modified gravity models, significantly narrowing the allowed parameter space.

Contribution

First simulation-calibrated cluster abundance constraints on f(R) gravity, improving previous bounds by nearly four orders of magnitude in field amplitude.

Findings

Stringent limits on f(R) field amplitude.

Reduced the force modification range from Gpc to tens of Mpc.

Enhanced constraints by nearly 4 orders of magnitude.

Abstract

Modified gravitational forces in models that seek to explain cosmic acceleration without dark energy typically predict deviations in the abundance of massive dark matter halos. We conduct the first, simulation calibrated, cluster abundance constraints on a modified gravity model, specifically the modified action f(R) model. The local cluster abundance, when combined with geometric and high redshift data from the cosmic microwave background, supernovae, H_0 and baryon acoustic oscillations, improve previous constraints by nearly 4 orders of magnitude in the field amplitude. These limits correspond to a 2 order of magnitude improvement in the bounds on the range of the force modification from the several Gpc scale to the tens of Mpc scale.