Cosmologies with scalar fields from higher dimensions applied to Bianchi type $\rm VI_{h=-1}$ model: classical and quantum solutions

TL;DR

This paper derives and analyzes classical and quantum solutions for a Bianchi type VI_{-1} cosmological model from a higher-dimensional scalar-tensor theory, revealing symmetries and exact solutions in both classical and quantum regimes.

Contribution

It constructs a four-dimensional effective model from higher-dimensional gravity with scalar fields and solves the classical and quantum equations for a specific anisotropic cosmology.

Findings

Exact classical solutions with hidden symmetry B=C

Quantum Wheeler-DeWitt equation solved explicitly

Scale factor behavior analyzed in both classical and quantum contexts

Abstract

In this work we construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. The corresponding action in four dimensions is similar to the action of K-essence theories. This approach is applied to anisotropic cosmological Bianchi type $VI_{(h=-1)}$ model for which we study the classical coupling of the anisotropic scale factors with the two real scalar moduli produced by the compactification process. The classical Einstein field equations give us a hidden symmetry, corresponding to equal radii B=C, which permits us to solve exactly the equations of motion. With this hidden symmetry, then we solve the FRW, finding that the scale factor goes to B radii. Also the corresponding Wheeler-DeWitt (WDW) equation in the context of Standard Quantum Cosmology is solved. Bohm's formalism for this cosmological model is revisited too.