Non-linear dynamics of the minimal theory of massive gravity

¹ Institute of Theoretical Astrophysics, University of Oslo, PO Box 1029, Blindern, 0315 Oslo, Norway
e-mail: robert.hagala@astro.uio.no
² Expert Analytics AS, Tordenskiolds gate 6, 0160 Oslo, Norway
³ Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, 606-8502 Kyoto, Japan
⁴ Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 277-8583 Chiba, Japan

Received: 30 November 2020
Accepted: 3 March 2021

Abstract

We investigate cosmological signatures of the minimal theory of massive gravity (MTMG). To this aim, we simulate the normal branch of the MTMG by employing the RAMSESN-body code and extending it with an effective gravitational constant G_eff. We implement an environment-dependent G_eff as a function of the graviton mass and the local energy density as predicted by MTMG. We find that halo density profiles are not a good probe for MTMG because deviations from general relativity (GR) are quite small. Similarly, the matter power spectra show deviations only at the percentage level. However, we find a clear difference between MTMG and GR in that voids are denser in MTMG than in GR. As measuring void profiles is quite a complex task from an observational point of view, a better probe of MTMG would be the halo abundances. In this case, MTMG creates a larger amount of massive halos, while there is a suppression in the abundance of small halos.