On (in)stabilities of perturbations in mimetic models with higher derivatives
General Relativity and Quantum Cosmology
2017-09-06 v3 Cosmology and Nongalactic Astrophysics
High Energy Physics - Theory
Abstract
Usually when applying the mimetic model to the early universe, higher derivative terms are needed to promote the mimetic field to be dynamical. However such models suffer from the ghost and/or the gradient instabilities and simple extensions cannot cure this pathology. We point out in this paper that it is possible to overcome this difficulty by considering the direct couplings of the higher derivatives of the mimetic field to the curvature of the spacetime.
Keywords
Cite
@article{arxiv.1704.06834,
title = {On (in)stabilities of perturbations in mimetic models with higher derivatives},
author = {Yunlong Zheng and Liuyuan Shen and Yicen Mou and Mingzhe Li},
journal= {arXiv preprint arXiv:1704.06834},
year = {2017}
}
Comments
10 pages, 1 figure, the version accepted by JCAP