Journal
PHYSICAL REVIEW LETTERS
Volume 119, Issue 25, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevLett.119.251302
Keywords
-
Categories
Funding
- CNRS/INSU, France
- French Agence Nationale de la Recherche [ANR-12-BS05-0002]
- Agence Nationale de la Recherche (ANR) [ANR-12-BS05-0002] Funding Source: Agence Nationale de la Recherche (ANR)
Ask authors/readers for more resources
The observation of GW170817 and its electromagnetic counterpart implies that gravitational waves travel at the speed of light, with deviations smaller than a few x 10(-15). We discuss the consequences of this experimental result for models of dark energy and modified gravity characterized by a single scalar degree of freedom. To avoid tuning, the speed of gravitational waves must be unaffected not only for our particular cosmological solution but also for nearby solutions obtained by slightly changing the matter abundance. For this to happen, the coefficients of various operators must satisfy precise relations that we discuss both in the language of the effective field theory of dark energy and in the covariant one, for Horndeski, beyond Horndeski, and degenerate higher-order theories. The simplification is dramatic: of the three functions describing quartic and quintic beyond Horndeski theories, only one remains and reduces to a standard conformal coupling to the Ricci scalar for Horndeski theories. We show that the deduced relations among operators do not introduce further tuning of the models, since they are stable under quantum corrections.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available