Galileons on Cosmological Backgrounds

TL;DR

This paper develops four-dimensional effective field theories for generalized DBI galileons on cosmological backgrounds, highlighting their symmetry properties and potential role in universe evolution.

Contribution

It introduces a new class of galileon theories on Friedmann-Robertson-Walker spacetimes with non-linear symmetries derived from higher-dimensional bulk symmetries.

Findings

Theories are invariant under non-linear transformations.

Framework for exploring galileons in cosmology.

Potential implications for universe evolution.

Abstract

We construct four-dimensional effective field theories of a generalized DBI galileon field, the dynamics of which naturally take place on a Friedmann-Robertson-Walker spacetime. The theories are invariant under non-linear symmetry transformations, which can be thought of as being inherited from five-dimensional bulk Killing symmetries via the probe brane technique through which they are constructed. The resulting model provides a framework in which to explore the cosmological role that galileons may play as the universe evolves.