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arXiv · 1101.5028

Auxiliary fields representation for modified gravity models

Davi C. Rodrigues·Filipe de O. Salles·Ilya L. Shapiro·Alexei A. Starobinsky
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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.

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Davi C. Rodrigues, Filipe de O. Salles, Ilya L. Shapiro, Alexei A. Starobinsky. 2011-01-26. Auxiliary fields representation for modified gravity models. https://doi.org/10.1103/physrevd.83.084028

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