We review the topic of 4D Einstein–Gauss–Bonnet (4DEGB) gravity, which has been the
subject of considerable interest over the past two years. Our review begins with a general …

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 …

We review spherical and inhomogeneous analytic solutions of the field equations of Einstein
and of scalar–tensor gravity, including Brans–Dicke theory, non-minimally (possibly …

Searching for violations of the no-hair theorem (NHT) is a powerful way to test gravity, and
more generally fundamental physics, particularly with regards to the existence of additional …

Recently new scalarized black hole solutions were constructed in the extended scalar-
tensor-Gauss-Bonnet gravity, where the scalar field is sourced by the curvature of the …

We consider an action for an Abelian gauge field for which the density is given by a power of
the Maxwell Lagrangian. In d spacetime dimensions this action is shown to enjoy conformal …

We naturally extend general relativity with a conformally coupled scalar field by only
requiring conformal invariance of the scalar field equation of motion and not of the action …

Chern-Simons gravity rotating Kerr-type black hole solutions are revisited from the point of
view of their scalarization, namely examining the backreaction of pseudoscalar axion fields …

A bstract We study certain bi-scalar-tensor theories emanating from conformal symmetry
requirements of Horndeski's four-dimensional action. The former scalar is a Galileon with …

The theory of massive gravity in three dimensions recently proposed by Bergshoeff, Hohm
and Townsend (BHT) is considered. At the special case when the theory admits a unique …