Reconstructing Horndeski theories from phenomenological modified gravity and dark energy models on cosmological scales

TL;DR

This paper develops a method to reconstruct Horndeski scalar-tensor theories from phenomenological dark energy and modified gravity models, analyzing their underlying theories and proposing a new stable parametrization basis.

Contribution

It introduces a reconstruction technique linking effective field theory parameters to Horndeski theories and proposes a novel stable parametrization basis for these models.

Findings

Reconstructed Horndeski theories from phenomenological models

Analyzed theories with weak gravity, shielding, and self-acceleration

Proposed a new stable parametrization basis

Abstract

Recently we have derived a set of mapping relations that enables the reconstruction of the family of Horndeski scalar-tensor theories which reproduce the background dynamics and linear perturbations of a given set of effective field theory of dark energy coefficients. In this paper we present a number of applications of this reconstruction. We examine the form of the underlying theories behind different phenomenological parameterizations of modified gravity and dark energy used in the literature, as well as examine theories that exhibit weak gravity, linear shielding, and minimal self-acceleration. Finally, we propose a new inherently stable parametrization basis for modified gravity and dark energy models.