Abstract
The only known fully ghost-free and consistent Lorentz-invariant kinetic term for a graviton (or indeed for any spin-2 field) is the Einstein-Hilbert term. Here we propose and investigate a new candidate family of kinetic interactions and their extensions to derivative interactions involving several spin-2 fields. These new terms generically break diffeomorphism invariance(s) and as a result can lead to the propagation of 5 degrees of freedom for a single spin-2 field—analogous to ghost-free Massive Gravity. We discuss under what circumstances these new terms can be used to build healthy effective field theories and in the process establish the `Jordan' and `Einstein' frame pictures for Massive-, Bi- and Multi-Gravity.
Original language | English |
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Article number | 025 |
Pages (from-to) | 1-26 |
Number of pages | 26 |
Journal | Journal of Cosmology and Astroparticle Physics |
Volume | 2015 |
Issue number | 04 |
DOIs | |
Publication status | Published - 17 Apr 2015 |
Keywords
- modified gravity
- gravity
- dark energy theory
- RCUK
- STFC