Stable bouncing solutions in teleparallel Horndeski gravity

Abstract

In order to have singularity-free solutions at the beginning of the Universe, we need to violate the null energy condition. In the general class of Horndeski gravity, there are healthy NEC-violating solutions, which however are plagued with instabilities or some kind of pathologies in the history of the Universe; this is known as the no-go theorem. In this paper, we study the possibility of stable bouncing solutions in the Teleparallel analogue of Horndeski gravity and we show explicitly that there exist healthy violations of the no-go theorem.