Auxiliary fields representation for modified gravity models
Abstract
We consider tensor-multiscalar representations for several types of modified gravity actions. The first example is the theory with the action representing an arbitrary smooth function of the scalar curvature R and (Box R), the integrand of the Gauss-Bonnet term and the square of the Weyl tensor. We present a simple procedure leading to an equivalent theory of a space-time metric and four auxiliary scalars and specially discuss calibration of a cosmological constant and the condition of the existence of dS-like solutions in the case of empty universe. The condition for obtaining a smaller number of independent scalar fields is derived. The second example is the Eddington-like gravity action. In this case we show, in particular, the equivalence of the theory to GR with the cosmological constant term, with or without use of the first-order formalism, and also discuss some possible generalizations.
Keywords
Cite
@article{arxiv.1101.5028,
title = {Auxiliary fields representation for modified gravity models},
author = {Davi C. Rodrigues and Filipe de O. Salles and Ilya L. Shapiro and Alexei A. Starobinsky},
journal= {arXiv preprint arXiv:1101.5028},
year = {2011}
}
Comments
Added a few comments on quantum properties and a new section about quantum UV completion of the classically equivalent theories, plus corresponding references. Fits the manuscript accepted for publication in Physical Review D. 29 pages, no figures