Anisotropic Mimetic Cosmology

Abstract

We consider a mimetic set up in which the mimetic scalar is coupled to a vector field. It is shown that such a field with a time-like component does not contribute to the background equations and yet produces healthy isocurvature perturbations with respect to ghost and gradient instabilities in spite of the absence of any propagating curvature perturbations at the level of the quadratic action. We then consider a vector field with space-like components which leads to an anisotropic Bianchi universe and show that the ghost and gradient instabilities are absent in the limit of high momenta and that the propagating curvature perturbations have healthy UV behavior.

arXiv comment12 pages, 4 figures, to appear in PRD

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• Consistency between black hole and mimetic gravity -- Case of $(2+1)$-dimensional gravity
• Mimetic Black Strings
• New anisotropic star solutions in mimetic gravity
• Topological black holes in mimetic gravity
• Structure formation in mimetic gravity
• Hamiltonian analysis of Mimetic gravity with higher derivatives
• Isotropic stellar model in mimetic theory
• Higher dimensional charged static and rotating solutions in mimetic gravity