176 citations · 3.9k across the 153 of their papers we have counts for
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Disformal Transition of a Black Hole to a Wormhole in Scalar-Tensor Horndeski Theory
Nikos Chatzifotis, Eleftherios Papantonopoulos, Christoforos Vlachos
We consider disformal transformations in a subclass of Horndeski theory in which a scalar field is kinetically coupled to the Einstein tensor. We apply a disformal transformation o…
Stability of black holes with non-minimally coupled scalar hair to the Einstein tensor
Nikos Chatzifotis, Christoforos Vlachos, Kyriakos Destounis +1
General relativity admits a plethora of exact compact object solutions. The augmentation of Einstein's action with non-minimal coupling terms leads to modified theories with rich s…
Gravity Wormholes sourced by a Phantom Scalar Field
Thanasis Karakasis, Eleftherios Papantonopoulos, Christoforos Vlachos
We derive an exact wormhole spacetime supported by a phantom scalar field in the context of gravity. Without specifying the form of the function, the scal…
Using atomic clocks to detect local dark matter halos
Chris Kouvaris, Eleftherios Papantonopoulos, Lauren Street +1
It is possible that bosonic dark matter forms halos around the Sun or the Earth. We discuss the possibility of probing such halos with atomic clocks. Focusing on either a Higgs por…
Hairy Black Holes in Disformal Scalar-Tensor Gravity Theories
Cristian Erices, Pantelis Filis, Eleftherios Papantonopoulos
We show that the no-hair theorem for scalar-tensor theories with bi-metric structure can be evaded. We find that hairy black hole solutions in the presence of an electric charge ad…
Exact Black Hole Solutions with a Conformally Coupled Scalar Field and Dynamic Ricci Curvature in Gravity Theories
Thanasis Karakasis, Eleftherios Papantonopoulos, Zi-Yu Tang +1
We report exact black hole solutions in asymptotically flat or (A)dS four-dimensional spacetime with a conformally coupled self-interacting scalar field in gravity. We first…