Nonminimal Scalar Effective Cosmology
Abstract
In this work we investigate the most general nonminimally coupled $\mathbb{Z}_2$ symmetric scalartensor effective field theory (EFT) of gravity up to dimension six in the operator expansion. The most general action is presented along with its equations of motion both in the covariant form and also in the coordinate form resulting from an FLRW analysis. The pressure and density of the scalar field are found as well as the equation of state parameter and some cosmological parameters. We analyse the background evolution of the scalar field within the framework of the slowroll approximation and provide a brief discussion of $\mathbb{Z}_2$ symmetry breaking of the scalar field which gives an order of magnitude constraint on one of the coupling constants. To provide a concrete example we choose a couple of potentials for the scalar field and explore the cosmology. Some brief comments on the range of validity of the EFT are also offered as well as the connections between the general model and wellknown examples in the literature.
 Publication:

arXiv eprints
 Pub Date:
 May 2023
 DOI:
 10.48550/arXiv.2305.13963
 arXiv:
 arXiv:2305.13963
 Bibcode:
 2023arXiv230513963H
 Keywords:

 High Energy Physics  Theory
 EPrint:
 13 pages, 0 figures