Scaling Cosmologies from Duality Twisted Compactifications

TL;DR

This paper investigates how duality symmetries in higher-dimensional theories enable the emergence of cosmological scaling solutions in four dimensions, especially when moduli fields have non-standard kinetic terms.

Contribution

It demonstrates that global SL(n,R) or O(2,2) symmetries in higher-dimensional actions facilitate scaling solutions in four-dimensional cosmologies with non-canonical kinetic energy.

Findings

Scaling solutions arise when higher-dimensional actions have SL(n,R) or O(2,2) symmetry.

Duality symmetries can generate non-trivial scaling behavior for moduli fields.

Compactification of eleven-dimensional gravity on elliptic twisted tori is explored.

Abstract

Oscillating moduli fields can support a cosmological scaling solution in the presence of a perfect fluid when the scalar field potential satisfies appropriate conditions. We examine when such conditions arise in higher-dimensional, non-linear sigma-models that are reduced to four dimensions under a generalized Scherk-Schwarz compactification. We show explicitly that scaling behaviour is possible when the higher-dimensional action exhibits a global SL(n,R) or O(2,2) symmetry. These underlying symmetries can be exploited to generate non-trivial scaling solutions when the moduli fields have non-canonical kinetic energy. We also consider the compactification of eleven-dimensional vacuum Einstein gravity on an elliptic twisted torus.