6 papers
Caustic formation in DBI models: Wave propagation on planar domain walls
E. Babichev, B. Gafarov, S. Ramazanov +1
We investigate propagation of generic waves on thin planar domain walls effectively described by the scalar Dirac-Born-Infeld model (DBI). We pay a particular attention to the poss…
Ghost-free, gauge invariant SVT generalizations of Horndeski theory
S. Mironov, A. Shtennikova, M. Valencia-Villegas
We analyze the generalizations of Kaluza--Klein compactifications of 5D Horndeski theory. They are Scalar--Vector--Tensor (SVT) theories with higher derivatives in the action, but…
Luminal Scalar-Tensor theories for a not so dark Dark Energy
S. Mironov, A. Shtennikova, M. Valencia-Villegas
In general the speed of Gravitational Waves (GWs) in Scalar-Tensor modifications of Einstein's gravity is different from the speed of Light. Nevertheless, it has been measured that…
Higher derivative SVT theories from Kaluza-Klein reductions of Horndeski theory
S. Mironov, A. Shtennikova, M. Valencia-Villegas
It was recently pointed out that some precise Photon-Galileon couplings in four dimensions (4D) -- inspired by a higher dimensional reduction -- are enough to obtain a Horndeski th…
Reviving Horndeski after GW170817 by Kaluza-Klein compactifications
S. Mironov, A. Shtennikova, M. Valencia-Villegas
The application of Horndeski theory/ Galileons for late time cosmology is heavily constrained by the strict coincidence in the speed of propagation of gravitational and electromagn…
Healthy Horndeski cosmologies with torsion
S. Mironov, M. Valencia-Villegas
We show that the full Horndeski theory with both curvature and torsion can support nonsingular, stable and subluminal cosmological solutions at all times. Thus, with torsion, the u…