491 citations · 6.8k across the 96 of their papers we have counts for
4 papers · 2 filters
Black Hole in a Radiation-Dominated Universe
Eugeny Babichev, Vyacheslav Dokuchaev, Yury Eroshenko
We study a black hole in an expanding Universe during the radiation-dominated stage. In the case when the black hole radius is much smaller than the cosmological horizon, we presen…
The sound of DHOST
Eugeny Babichev, Antoine Lehébel
We show that, in generic higher-order scalar-tensor theories which avoid the Ostrogradsky instability, the presence of a scalar field significantly modifies the propagation of matt…
Recovering P(X) from a canonical complex field
Eugeny Babichev, Sabir Ramazanov, Alexander Vikman
We study the correspondence between models of a self-interacting canonical complex scalar field and P(X)-theories/shift-symmetric k-essence. Both describe the same background cosmo…
Hamiltonian vs stability and application to Horndeski theory
Eugeny Babichev, Christos Charmousis, Gilles Esposito-Farese +1
A Hamiltonian density bounded from below implies that the lowest-energy state is stable. We point out, contrary to common lore, that an unbounded Hamiltonian density does not neces…