Kantowski-Sachs and Bianchi type models with a general non-canonical scalar field

Abstract

The paper deals with spatially homogeneous and anisotropic Kantowski-Sachs and Bianchi universes with a general non-canonical scalar field with the Lagrangian L = F(X) − Ω(ϕ), where \(X = \frac{1}{2}{\phi _i}{\phi ^i}\). We discuss a general non-canonical scalar field in three different cosmologies: (i) cosmology with a constant potential, Ω(ϕ) = Ω₀ = const, (ii) cosmology with a constant equation-of-state parameter, i.e., γ_ϕ = const, and (iii) cosmology with a constant speed of sound, i.e., c_s² = const. For a constant potential, we have shown that the k-essence Lagrangian and the Lagrangian of the present model are equivalent. Dissipation of anisotropy, when the universe is filled with a general non-canonical scalar field, is investigated. The existence of an average bounce in Kantowski-Sachs and locally rotationally symmetric Bianchi-I and Bianchi-III models is discussed in detail.