Phantom crossing dark energy in Horndeski's theory

Abstract

The $\Lambda$CDM model is a remarkably successful model which is consistent with the observations of cosmic microwave background radiation (CMB), baryon acoustic oscillation (BAO), and large scale structure of the Universe. However, the discrepancy in the value of $H_0$ between the local observations and PLANCK observation of CMB was recently pointed out. One of the way to ease the discrepancy is to introduce phantom dark energy instead of the cosmological constant. While, phantom dark energy often suffer from the instabilities. We will investigate the general solution to overcome the difficulty of phantom dark energy and construct some particular models which have a phantom crossing and can be consistent with the observations.