Massive and modified gravity as self-gravitating media

Guillermo Ballesteros (1, 2) , Comelli Denis (3) , Pilo Luigi (4)

1 IPHT - Institut de Physique Théorique - UMR CNRS 3681
2 Theory Division
3 INFN - Istituto Nazionale di Fisica Nucleare [Ferrara]
4 Dipartimento di Scienze Fisiche e Chimiche [L'Aquila]

We study the effective field theory that describes the low-energy physics of self-gravitating media. The field content consists of four derivatively coupled scalar fields that can be identified with the internal comoving coordinates of the medium. Imposing SO(3) internal spatial invariance, the theory describes supersolids. Stronger symmetry requirements lead to superfluids, solids and perfect fluids, at lowest order in derivatives. In the unitary gauge, massive gravity emerges, being thus the result of a continuous medium propagating in spacetime. Our results can be used to explore systematically the effects and signatures of modifying gravity consistently at large distances. The dark sector is then described as a self-gravitating medium with dynamical and thermodynamic properties dictated by internal symmetries. These results indicate that the divide between dark energy and modified gravity, at large distance scales, is simply a gauge choice.

Domaines: Physique des Hautes Energies - Théorie [hep-th]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Relativité Générale et Cosmologie Quantique [gr-qc]; Physique des Hautes Energies - Phénoménologie [hep-ph]

Guillermo Ballesteros, Comelli Denis, Pilo Luigi. Massive and modified gravity as self-gravitating media. Physical Review D, 2016, 94, pp.124023. ⟨10.1103/PhysRevD.94.124023⟩. ⟨cea-01296404⟩