Scalar-tensor $\sigma$-cosmologies

TL;DR

This paper demonstrates that scalar-tensor sigma-models are conformally equivalent to general relativity with a minimally coupled wavemap, leading to natural inflation driven by curvature couplings and wavemap interactions.

Contribution

It establishes a conformal equivalence between scalar-tensor sigma-models and general relativity with a wavemap, providing a new perspective on inflation mechanisms.

Findings

Scalar-tensor sigma-models are conformally equivalent to GR with wavemaps.

Inflation naturally arises from curvature couplings and wavemap self-interactions.

The framework offers a new approach to modeling inflation in cosmology.

Abstract

We show that the scalar-tensor $\sigma$-model action is conformally equivalent to general relativity with a minimally coupled wavemap with a particular target metric. Inflation on the source manifold is then shown to occur in a natural way due both to the arbitrary curvature couplings and the wavemap self-interactions.