Extended anisotropic models in noncompact Kaluza-Klein theory

TL;DR

This paper derives new exact solutions for extended anisotropic models in five-dimensional modified Brans-Dicke theory, analyzing their four-dimensional dynamics and implications for Kaluza-Klein cosmology.

Contribution

It introduces extended 5D anisotropic models within modified Brans-Dicke theory and explores their induced 4D cosmological dynamics, extending previous work in standard Brans-Dicke and related theories.

Findings

New exact solutions for 5D LRS space-times

Analysis of scale factor evolution of extra dimension

Comparison with standard Brans-Dicke and general relativity results

Abstract

In this paper, new exact solutions for locally rotational symmetric (LRS) space-times are obtained within the modified Brans-Dicke theory (MBDT) (Rasouli et al 2014 Class. Quantum Grav. 31 115002). Specifically, extended five-dimensional (5D) versions of Kantowski-Sachs, LRS Bianchi type I and Bianchi type III are investigated in the context of the standard Brans-Dicke theory. We subsequently extract their corresponding dynamics on a 4D hypersurface. Our results are discussed regarding others obtained in the standard Brans-Dicke theory, induced-matter theory and general relativity. Moreover, we comment on the evolution of the scale factor of the extra spatial dimension, which is of interest in Kaluza-Klein frameworks.