Inflation from String/M-Theory Compactification?

TL;DR

This paper investigates the potential for obtaining accelerating 4D cosmologies from String/M-theory compactifications, demonstrating conditions under which positive scalar potentials lead to eternal acceleration, thus addressing the no-go theorem.

Contribution

It provides exact scalar potentials for dimensionally reduced theories and identifies conditions for eternal acceleration in hyperbolic and flux compactifications.

Findings

Positive scalar potentials in hyperbolic compactifications evade the no-go theorem.

Eternal acceleration occurs with specific gauge field configurations and potential parameters.

Accelerating cosmologies are possible with flat or hyperbolic 4D space-times under certain conditions.

Abstract

We present some exact scalar potentials for the dimensionally reduced theory and examine the possibility of obtaining accelerating 4d cosmology from String/M-theory, more generally, hyperbolic and flux compactification. In the hyperbolic case, even in the zero-flux limit, the scalar potential is positive for the 4d effective theory as required to get an accelerating universe, and thereby evading the ``no-go theorem'' given for static internal space. When we turn on the gauge fields as source terms at the cosmological background with potential V\propto exp(-2c\phi), we find eternally accelerating cosmologies when the 4d space-time is flat and c\geq 1, or hyperbolic and 1<c<\sqrt{2}.