Can the universe exit from phantom inflation due to gravitational back reaction?

Abstract

The effects of the gravitational back reaction of cosmological perturbations are investigatedin a phantom inflation model. The effective energy–momentum tensor of thegravitational back reaction of cosmological perturbations whose wavelengths arelarger than the Hubble radius is calculated. Our results show that the effectsof gravitational back reaction will counteract that of the phantom energy. It isdemonstrated in a chaotic phantom inflation model that if the phantom field at the end ofinflation is larger than a critical value determined by the necessary e-folds, thephantom inflation phase might be terminated by the gravitational back reaction.