Covariant Galileon
Abstract
We consider the recently introduced “Galileon” field in a dynamical spacetime. When the Galileon is assumed to be minimally coupled to the metric, we underline that both field equations of the Galileon and the metric involve up to thirdorder derivatives. We show that a unique nonminimal coupling of the Galileon to curvature eliminates all higher derivatives in all field equations, hence yielding secondorder equations, without any extra propagating degree of freedom. The resulting theory breaks the generalized “Galilean” invariance of the original model.
 Publication:

Physical Review D
 Pub Date:
 April 2009
 DOI:
 10.1103/PhysRevD.79.084003
 arXiv:
 arXiv:0901.1314
 Bibcode:
 2009PhRvD..79h4003D
 Keywords:

 04.50.h;
 11.10.z;
 98.80.k;
 Higherdimensional gravity and other theories of gravity;
 Field theory;
 Cosmology;
 High Energy Physics  Theory;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 10 pages, no figure, RevTeX4 format