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The Cosmology of a Universe with Spontaneously-Broken Lorentz Symmetry

P. G. Ferreira·B. M. Gripaios·R. Saffari·T. G. Zlosnik
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Abstract

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.

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P. G. Ferreira, B. M. Gripaios, R. Saffari, T. G. Zlosnik. 2006-10-04. The Cosmology of a Universe with Spontaneously-Broken Lorentz Symmetry. https://doi.org/10.1103/physrevd.75.044014

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