491 citations · 6.8k across the 96 of their papers we have counts for
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Cherenkov radiation as ghost instability
Eugeny Babichev
We demonstrate that Cherenkov radiation can be interpreted as ghost instability of a certain type. Solutions of modified gravity theories often contain ghost instabilities. One typ…
Horndeski speed tests with scalar-photon couplings
Eugeny Babichev, Christos Charmousis, Benjamin Muntz +2
We revisit multi-messenger constraints from neutron star mergers on the speed of propagation of gravitational and electromagnetic waves in Horndeski and beyond Horndeski theories.…
Global conformal symmetry in scalar-tensor theories
Eugeny Babichev, Christos Charmousis, Mokhtar Hassaine +1
We study a subclass of Horndeski gravity which has both global conformal and shift symmetries. Global symmetries are characterised by the presence of a conserved current which has…
Generalisation of Conformal-Disformal Transformations of the Metric in Scalar-Tensor Theories
Eugeny Babichev, Keisuke Izumi, Karim Noui +2
We study new classes of metric transformations in the context of scalar-tensor theories, which involve both higher derivatives of the scalar field and derivatives of the metric its…
Testing disformal non-circular deformation of Kerr black holes with LISA
Eugeny Babichev, Christos Charmousis, Daniela D. Doneva +2
There is strong observational evidence that almost every large galaxy has a supermassive black hole at its center. It is of fundamental importance to know whether such black holes…
The cosmic trimmer: Black-hole hair in scalar-Gauss-Bonnet gravity is altered by cosmology
Eugeny Babichev, Ignacy Sawicki, Leonardo G. Trombetta
Static black holes in general relativity modified by a linear scalar coupling to the Gauss-Bonnet invariant always carry hair. We show that the same mechanism that creates the hair…