Multidimensional world, inflation and modern acceleration

TL;DR

This paper develops a multidimensional gravity model with curvature-nonlinear terms that naturally produces both early inflation and modern acceleration, aligning with observations without small parameters.

Contribution

It introduces a cosmological model derived from pure multidimensional gravity that explains inflation and acceleration through effective scalar fields linked to extra dimensions.

Findings

Model reproduces inflation and current acceleration consistent with data.

Effective inflaton mass depends on initial conditions, explaining its smallness.

Predicts future changes in physical laws due to increasing extra dimensions.

Abstract

Starting from pure multidimensional gravity with curvature-nonlinear terms but no matter fields in the initial action, we obtain a cosmological model with two effective scalar fields related to the size of two extra factor spaces. The model includes both an early inflationary stage and that of modern accelerated expansion and satisfies the observational data. There are no small parameters; the effective inflaton mass depends on the initial conditions which explain its small value as compared to the Planck mass. At the modern stage, the size of extra dimensions slowly increases, therefore this model predicts drastic changes in the physical laws of our Universe in the remote future.