Anisotropic Inflation from Extra Dimensions

TL;DR

This paper explores how vacuum multidimensional cosmological models with internal Lie group manifolds can naturally lead to accelerated expansion of the external universe, driven by internal space dynamics without fine tuning.

Contribution

It introduces a novel class of models with internal spaces as Lie group manifolds, demonstrating generic power law inflation driven by internal space evolution without fine tuning.

Findings

Internal space dynamics induce power law inflation.

The model does not require fine tuning or inflaton potentials.

Internal volume grows logarithmically during inflation.

Abstract

Vacuum multidimensional cosmological models with internal spaces being compact $n$-dimensional Lie group manifolds are considered. Products of 3-spheres and $SU(3)$ manifold (a novelty in cosmology) are studied. It turns out that the dynamical evolution of the internal space drives an accelerated expansion of the external world (power law inflation). This generic solution (attractor in a phase space) is determined by the Lie group space without any fine tuning or arbitrary inflaton potentials. Matter in the four dimensions appears in the form of a number of scalar fields representing anisotropic scale factors for the internal space. Along the attractor solution the volume of the internal space grows logarithmically in time. This simple and natural model should be completed by mechanisms terminating the inflationary evolution and transforming the geometric scalar fields into ordinary particles.