Heavy spin-2 Dark Matter

TL;DR

This paper proposes that a heavy spin-2 particle, described by ghost-free bimetric theory, can account for dark matter phenomena, fitting cosmological and local gravity tests and predicting a mass in the 1-100 TeV range.

Contribution

It introduces a model where a heavy spin-2 field explains dark matter, consistent with current observations and tests, extending General Relativity with ghost-free bimetric theory.

Findings

Heavy spin-2 particle can explain dark matter observations.

The model is consistent with cosmological and local gravity tests.

Predicted spin-2 mass range is 1 to 100 TeV.

Abstract

We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the requirement of stability constrains the spin-2 mass to be in the 1 to 100 TeV range.