This article is intended to review the recent developments in the Horndeski theory and its
generalization, which provide us with a systematic understanding of scalar–tensor theories …

This paper reviews scalar–tensor theories characterized by a Lagrangian that, despite the
presence of second-order derivatives, contains a single scalar degree of freedom. These …

We study new consistent scalar-tensor theories of gravity recently introduced by Langlois
and Noui with potentially interesting cosmological applications. We derive the conditions for …

We consider all degenerate scalar-tensor theories that depend quadratically on second-
order derivatives of a scalar field, which we have identified in a previous work. These …

Mimetic gravity is a Weyl‐symmetric extension of General Relativity, related to the latter by a
singular disformal transformation, wherein the appearance of a dust‐like perfect fluid can …

Mimetic gravity has gained significant appeal in cosmological contexts, but static spherically
symmetric space-times within the baseline theory are highly non-trivial: the two natural …

We perform a Hamiltonian analysis of a large class of scalar-tensor Lagrangians which
depend quadratically on the second derivatives of a scalar field. By resorting to a convenient …

Most existing theories of dark energy and/or modified gravity, involving a scalar degree of
freedom, can be conveniently described within the framework of the Effective Theory of Dark …

Invertible disformal transformations serve as a useful tool to explore ghost-free scalar-tensor
theories. In this paper, we construct a generalization of invertible disformal transformations …

In this work, we analyse static spherically symmetric solutions in the framework of mimetic
gravity, an extension of general relativity where the conformal degree of freedom of gravity is …