The Cosmology of a Universe with Spontaneously-Broken Lorentz Symmetry

A self consistent effective field theory of modified gravity has recently been proposed with spontaneous breaking of local Lorentz invariance. The symmetry is broken by a vector field with the wrong-sign mass term and it has been shown to have additional graviton modes and modified dispersion relati...

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Bibliographic Details
Main Authors: Ferreira, P, Gripaios, B, Saffari, R, Zlosnik, T
Format: Journal article
Published: 2006
Description
Summary:A self consistent effective field theory of modified gravity has recently been proposed with spontaneous breaking of local Lorentz invariance. The symmetry is broken by a vector field with the wrong-sign mass term and it has been shown to have additional graviton modes and modified dispersion relations. In this paper we study the evolution of a homogeneous and isotropic universe in the presence of such a vector field with a minimum lying along the time-like direction. A plethora of different regimes is identified, such as accelerated expansion, loitering, collapse and tracking.