Dynamics of Einstein–Aether scalar field cosmology

Abstract

In the context of Einstein-aether scalar field cosmology we solve the field equations and determine exact and analytic solutions. In particular, we consider a model proposed by Kanno and Soda where the aether and the scalar fields interact through the aether coefficient parameters, which are promoted to be functions of the scalar field. For this model, we write the field equations by using the minisuperspace approach and we determine the scalar field potentials which leads to Liouvilleintegrable systems. We solve the field equations for five families of scalar field potentials and, whether it is feasible, we write down the analytic solutions by using closed-form functions. 95.35.+d, 95.36.+x

Extended analysis for the evolution of the cosmological history in Einstein-aether scalar field theory

“…In addition when ζ = 0, that is W (φ) = const. we see that the latter dynamical system reduces to the one of [55] as expected. Before we continue with the rest of our analysis we present the different families of stationary points.…”

“…We preformed an extended analysis on the dynamics of the Einstein-Aether cosmology with a scalar field coupled to the aether field by generalized the analysis presented in [55]. Such an analysis is important in order to understand the viability of the Einstein-aether scalar field cosmology, as also to understand the contribution of new interaction terms, between the scalar field and the aether field, in the gravitational field equations.…”

“…The main results of this work are presented in Section 4 where we derive the stationary points for the four possible families of points, while we determine the stability conditions. Finally, in Section 5 we discuss our results by comparing them with that of the analysis in [55] and we draw our conclusions.…”

“…For this generic potential form exact solutions also determined, from where we found that except the scaling solution a (t) = a 0 t p and the de Sitter universe a (t) = a 0 e H0t , we can construct other kind of solutions such is the ΛCDM universe with a (t) = a 0 sinh 2 3 2 3 Λt . In this work we extend the analysis of [55] by assuming the potential form to be…”

“…In this work we extend the analysis of [55], by considered a more generic form of the scalar-field interaction model for the Einstein-aether cosmology. Because of the form of the interaction which we assume our analysis is valid and for the two different Einstein-aether scalar field theories presented by Donnelly et al [29] and Kanno et al [50].…”