129 citations · 453 across the 8 of their papers we have counts for
8 papers
Superradiant Instabilities in a Class of Scalar-Tensor Horndeski Theory
Theodoros Kolyvaris, Marina Koukouvaou, Antri Machattou +1
We study the superradiance effect in a class of scalar-tensor Horndeski theory. We first study the dynamics of a massive charged scalar wave scattered off the horizon of a Reissner…
Superradiant Amplification of a Scalar Wave Coupled Kinematically to Curvature Scattered off a Reissner-Nordström Black Hole
Theodoros Kolyvaris, Eleftherios Papantonopoulos
We study the dynamics of a massive charged scalar wave which except its canonical coupling to gravity it is also coupled kinematically to Einstein tensor. We find that as the stren…
Black Holes in Bi-scalar Extensions of Horndeski Theories
Christos Charmousis, Theodoros Kolyvaris, Eleftherios Papantonopoulos +1
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 shift symmetr…
Phase Transition to a Hairy Black Hole in Asymptotically Flat Spacetime
Theodoros Kolyvaris, George Koutsoumbas, Eleftherios Papantonopoulos +1
We discuss a phase transition of a Reissner-Nordström black hole to a hairy black hole in asymptotically flat spacetime. The hair is due to a massive charged scalar field. The no-h…
Scalar Hair from a Derivative Coupling of a Scalar Field to the Einstein Tensor
Theodoros Kolyvaris, George Koutsoumbas, Eleftherios Papantonopoulos +1
We consider a gravitating system of vanishing cosmological constant consisting of an electromagnetic field and a scalar field coupled to the Einstein tensor. A Reissner-Nordström b…
Lovelock solutions in the presence of matter sources
Yannis Bardoux, Christos Charmousis, Theodoros Kolyvaris
For a large class of space and time-dependent warped geometries we find the general solution of the 6-dimensional Einstein-Gauss-Bonnet equations in the presence of p-form matter f…