7 papers
Neutron stars with primary scalar hair
Hamza Boumaza, Christos Charmousis, David Langlois +1
We investigate static and spherically symmetric neutron star solutions endowed with primary scalar hair in a subfamily of Degenerate-Higher-Order-Scalar-Tensor (DHOST) theories of…
Radial Perturbations of Black Holes in DHOST Theories
Christos Charmousis, Simon Iteanu, David Langlois +1
We study radial perturbations of static black holes with primary hair in a subfamily of degenerate higher-order scalar-tensor (DHOST) theories. We recast the equation of motion for…
An effective cosmological constant as black hole primary hair
Christos Charmousis, Pedro G. S. Fernandes, Mokhtar Hassaine
We study Generalized Proca theories inspired by the recent regularised Proca theory of four-dimensional Gauss-Bonnet gravity. By abandoning the rigid constraints typically imposed…
Theoretical filters for shift-symmetric Horndeski gravities
Athanasios Bakopoulos, Christos Charmousis, Nikos Chatzifotis +1
We investigate the structure of nontrivial maximally symmetric vacua and compact-object solutions in shift-symmetric scalar-tensor theories. Focusing on Horndeski gravity, we deriv…
Rotating spacetimes with a free scalar field in four and five dimensions
José Barrientos, Christos Charmousis, Adolfo Cisterna +1
We construct explicit rotating solutions in Einstein's theory of relativity with a minimally coupled free scalar field rederiving and finding solutions in four or five spacetime di…
Proca theory of four-dimensional regularized Gauss-Bonnet gravity and black holes with primary hair
Christos Charmousis, Pedro G. S. Fernandes, Mokhtar Hassaine
We introduce a novel, well-defined four-dimensional regularized Gauss-Bonnet theory of gravity by applying a dimensional regularization procedure. The resulting theory is a vector-…