Disformal Transformations in Scalar-Torsion Gravity

We study disformal transformations in the context of scalar extensions to teleparallel gravity, in which the gravitational interaction is mediated by the torsion of a flat, metric compatible connection. We find a generic class of scalar-torsion actions which is invariant under disformal transformations, and which possesses different invariant subclasses. For the most simple of these subclasses we explicitly derive all terms that may appear in the action. We propose to study actions from this class as possible teleparallel analogues of healthy beyond Horndeski theories.Comment: LaTeX, 11 pages. Contribution to the proceedings of the conference "Teleparallel Universes" in Salamanca 26-28 November 2018; published versio

Parameterized post-Newtonian limit of Horndeski's gravity theory

We present a recent result on the parameterized post-Newtonian (PPN) limit of Horndeski's gravity theory and its consistency with solar system observations.Comment: 2 pages, no figures; to appear in the conference proceedings of the XIIth International Conference on Gravitation, Astrophysics and Cosmology, World Scientific Publishing Compan