Multi-field galileons and higher co-dimension branes

Abstract

In the decoupling limit, the DGP model reduces to the theory of a scalar field pi, with interactions including a specific cubic self-interaction - the galileon term. This term, and its quartic and quintic generalizations, can be thought of as arising from a probe 3-brane in a 5-dimensional bulk with Lovelock terms on the brane and in the bulk. We study multi-field generalizations of the galileon, and extend this probe brane view to higher co-dimensions. We derive an extremely restrictive theory of multiple galileon fields, interacting through a quartic term controlled by a single coupling, and trace its origin to the induced brane terms coming from Lovelock invariants in the higher co-dimension bulk. We explore some properties of this theory, finding de Sitter like self accelerating solutions. These solutions have ghosts if and only if the flat space theory does not have ghosts. Finally, we prove a general non-renormalization theorem: multi-field galileons are not renormalized quantum mechanically to any loop in perturbation theory.

34 pages, 2 figures. v2 typos corrected, comments added, version appearing in PRD

References in corpus (8)

• Covariant Galileon
• Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors
• Imperfect Dark Energy from Kinetic Gravity Braiding
• Galileon Cosmology
• DBI and the Galileon reunited
• Counterterms in Dimensionally Continued AdS Gravity
• (De)coupling Limit of DGP
• Higher Curvature Brane Corrections to the DGP Model

Cited by in corpus (9)

• Galileon inflation
• Symmetries for Galileons and DBI scalars on curved space
• Matter perturbations in Galileon cosmology
• General Embedded Brane Effective Field Theories
• Stability and superluminality of spherical DBI galileon solutions
• Theories of Dark Energy with Screening Mechanisms
• Cosmology of the selfaccelerating third order Galileon
• Instabilities of Spherical Solutions with Multiple Galileons and SO(N) Symmetry
• Goldstone's Theorem and Hamiltonian of Multi-galileon Modified Gravity