Linear growth of structure in projected massive gravity

TL;DR

This paper studies how matter fluctuations grow in a specific ghost-free massive gravity model, finding that modifications are minimal at small scales and identifying observationally viable parameter regions.

Contribution

It introduces a concrete, ghost-free projected massive gravity model and analyzes its impact on linear matter growth, providing observational constraints.

Findings

Modification to linear growth is strongly suppressed at subhorizon scales.

A parameter region exists that aligns with both observations and theoretical consistency.

The model is free of the Boulware-Deser ghost and preserves Lorentz symmetry.

Abstract

In the present paper, we investigate the linear growth of matter fluctuations based on a concrete model of the projected massive gravity, which is free of the Boulware-Deser ghost and preserves the global Lorentz symmetry. We found that at subhorizon scales, the modification to the linear growth is strongly suppressed even without nonlinear screening of an additional force. In addition, we obtain observational constraints from distance and redshift space distortion measurements and find that there is a parameter region that is consistent both observationally and theoretically.