70 AIM, UMR 7158, CEA/DRF, CNRS, Université Paris Diderot, Irfu/Service d'Astrophysique,
Centre de Saclay, FR-91191 Gif-sur-Yvette, France

We review recent developments and results in testing general relativity (GR) at cosmological
scales. The subject has witnessed rapid growth during the last two decades with the aim of …

Horizon-scale images of black holes (BHs) and their shadows have opened an
unprecedented window onto tests of gravity and fundamental physics in the strong-field …

The gravitational wave observations GW150914 and GW151226 by Advanced LIGO provide
the first opportunity to learn about physics in the extreme gravity environment of coalescing …

We introduce a new class of scalar-tensor theories that extend Horndeski, or" generalized
galileon", models. Despite possessing equations of motion of higher order in derivatives, we …

In this review we present a thoroughly comprehensive survey of recent work on modified
theories of gravity and their cosmological consequences. Amongst other things, we cover …

Gravitational waves (GWs) provide a new tool to probe the nature of dark energy (DE) and
the fundamental properties of gravity. We review the different ways in which GWs can be …

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 …

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 …

We review and extend a novel approach that we recently introduced, to describe general
dark energy or scalar-tensor models. Our approach relies on an Arnowitt-Deser-Misner …