Higher-derivative operators and effective field theory for general scalar-tensor theories
Abstract
We discuss the extent to which it is necessary to include higher-derivative operators in the effective field theory of general scalar-tensor theories. We explore the circumstances under which it is correct to restrict to second-order operators only, and demonstrate this using several different techniques, such as reduction of order and explicit field redefinitions. These methods are applied, in particular, to the much-studied Horndeski theories. The goal is to clarify the application of effective field theory techniques in the context of popular cosmological models, and to explicitly demonstrate how and when higher-derivative operators can be cast into lower-derivative forms suitable for numerical solution techniques.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- February 2018
- DOI:
- 10.1088/1475-7516/2018/02/031
- arXiv:
- arXiv:1709.09695
- Bibcode:
- 2018JCAP...02..031S
- Keywords:
-
- High Energy Physics - Theory;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology
- E-Print:
- 37+3 pages. v2: version published in JCAP