Stable cosmological solutions in Horndeski theory

TL;DR

This paper introduces a novel method for constructing stable cosmological solutions within Horndeski theory, overcoming previous no-go restrictions by considering singular gauge conditions, resulting in stable bouncing and genesis universes described by GR with unconventional scalar fields.

Contribution

The paper presents a new approach to achieve stable solutions in Horndeski theory by utilizing singular gauge conditions, expanding the possibilities for stable cosmological models.

Findings

Constructed spatially flat, stable bouncing universe solutions.

Developed genesis universe solutions within Horndeski theory.

Demonstrated stability despite no-go theorem restrictions.

Abstract

It is known that the construction of a completely stable solution in Horndeski theory is restricted very strongly by the so-called no-go theorem. Previously, various techniques have been used to avoid the conditions of the theorem. In this paper a new way of constructing stable solutions are shown in the general Horndeski theory. We considered the situation in which the unitary gauge studied earlier turns out to be singular. On this basis we construct a spatially flat, stable bouncing and genesis Universe solutions which are described by General Relativity with non-conventional scalar field.