Dark energy loopholes some time after GW170817

Bordin, Lorenzo; Copeland, Edmund J; Padilla, Antonio

Abstract

We revisit the constraints on scalar tensor theories of modified gravity following the purge of GW170817. We pay particular attention to dynamical loopholes where the anomalous speed of propagation of the gravitational wave can vanish on-shell, when we impose the dynamical field equations. By working in the effective field theory formalism we are able to improve on previous analyses, scanning a much wider class of theories, including Beyond Horndeski and DHOST. Furthermore, the formalism is well adapted to consider the effect of inhomogeneous perturbations, where we explicitly take into account the fact that the galactic overdensities are pressureless to leading order.

Citation

Bordin, L., Copeland, E. J., & Padilla, A. (2020). Dark energy loopholes some time after GW170817. Journal of Cosmology and Astroparticle Physics, 2020(11), Article 063. https://doi.org/10.1088/1475-7516/2020/11/063

• Journal Article Type: Article
• Acceptance Date: Oct 6, 2020
• Online Publication Date: Nov 30, 2020
• Publication Date: 2020-11
• Deposit Date: Oct 28, 2020
• Publicly Available Date: Dec 1, 2021
• Journal: Journal of Cosmology and Astroparticle Physics
• Electronic ISSN: 1475-7516
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 2020
• Issue: 11
• Article Number: 063
• DOI: https://doi.org/10.1088/1475-7516/2020/11/063
• Keywords: dark energy theory, gravitational waves / theory, modified gravity
• Public URL: https://nottingham-repository.worktribe.com/output/4996003
• Publisher URL: https://iopscience.iop.org/article/10.1088/1475-7516/2020/11/063