57 citations · 91 across the 7 of their papers we have counts for
7 papers
Effective dark matter fluid with higher derivative corrections
N. A. Koshelev
The effective field theory for hydrodynamics allows to write the action functional for fluid. In this paper, some simplest possible higher derivative terms in the fluid action and…
Spatial averaging and a non-Gaussianity
N. A. Koshelev
The spatial averaging used for the splitting of the local scale factor on the homogeneous background and small inhomogeneous perturbation leads to a non-local relationship between…
To the study of non-Gaussianity in two-field slow-roll inflation
N. A. Koshelev
The general expression for the second order large scale curvature perturbation in the form of a functional over a background solution is derived. The explicit expressions was obtai…
Non-adiabatic perturbations in multi-component perfect fluids
N. A. Koshelev
The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbat…
On the growth of perturbations in interacting dark energy and dark matter fluids
N. A. Koshelev
The covariant generalizations of the background dark sector coupling suggested in G. Mangano, G. Miele and V. Pettorino, Mod. Phys. Lett. A 18, 831 (2003) are considered. The evolu…
Comments on scalar-tensor representation of nonlocally corrected gravity
N. A. Koshelev
The scalar-tensor representation of nonlocally corrected gravity is considered. Some special solutions of the vacuum background equations were obtained that indicate to the nonequi…