Bimetric gravity is cosmologically viable
arXiv:1503.07521 · doi:10.1016/j.physletb.2015.06.062
Abstract
Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous work has suggested that its cosmological solutions are generically plagued by instabilities. We show that by taking the Planck mass for the second metric, , to be small, these instabilities can be pushed back to unobservably early times. In this limit, the theory approaches general relativity with an effective cosmological constant which is, remarkably, determined by the spin-2 interaction scale. This provides a late-time expansion history which is extremely close to CDM, but with a technically-natural value for the cosmological constant. We find should be no larger than the electroweak scale in order for cosmological perturbations to be stable by big-bang nucleosynthesis. We further show that in this limit the helicity-0 mode is no longer strongly-coupled at low energy scales.
8+2 pages, 2 tables. Version published in PLB. Minor typo corrections from v3
References in corpus (28)
- Resummation of Massive Gravity
- Massive gravity: nonlinear instability of the homogeneous and isotropic universe
- Multi-field galileons and higher co-dimension branes
- Accelerated expansion from ghost-free bigravity: a statistical analysis with improved generality
- On couplings to matter in massive (bi-)gravity
- Stable and unstable cosmological models in bimetric massive gravity
- Ghosts & Matter Couplings in Massive (bi-&multi-)Gravity
- Non-Renormalization and Naturalness in a Class of Scalar-Tensor Theories
- Spontaneous Lorentz Breaking and Massive Gravity
- Viable cosmology in bimetric theory
- Cosmological perturbations in massive bigravity
- Massive gravity from bimetric gravity
- Gravitational waves in bigravity cosmology
- The coupling to matter in Massive, Bi- and Multi-Gravity
- Cosmic expansion histories in massive bigravity with symmetric matter coupling
- Appearance of Boulware-Deser ghost in bigravity with doubly coupled matter
- Particular Solutions in Bimetric Theory and Their Implications
- Cosmology in bimetric theory with an effective composite coupling to matter
- Linear growth of structure in massive bigravity
- Higuchi Ghosts and Gradient Instabilities in Bimetric Gravity
- Cosmology of bigravity with doubly coupled matter
- Cosmological perturbations in massive gravity with doubly coupled matter
- Quantum corrections in massive bigravity and new effective composite metrics
- Integrated Sachs-Wolfe effect in massive bigravity
- Mass eigenstates in bimetric theory with matter coupling
- Cosmological viability of massive gravity with generalized matter coupling
- Surfing gravitational waves: can bigravity survive growing tensor modes?
- On Consistent Kinetic and Derivative Interactions for Gravitons