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More about spontaneous Lorentz-violation and infrared modification of gravity

M. V. Libanov·V. A. Rubakov
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Abstract

We consider a model with Lorentz-violating vector field condensates, in which dispersion laws of all perturbations, including tensor modes, undergo non-trivial modification in the infrared. The model is free of ghosts and tachyons at high 3-momenta. At low 3-momenta there are ghosts, and at even lower 3-momenta there exist tachyons. Still, with appropriate choice of parameters, the model is phenomenologically acceptable. Beyond a certain large distance scale and even larger time scale, the gravity of a static source changes from that of General Relativity to that of van Dam--Veltman--Zakharov limit of the Fierz--Pauli theory. Yet the late time cosmological evolution is always determined by the standard Friedmann equation, modulo small correction to the ``cosmological Planck mass'', so the modification of gravity cannot by itself explain the accelerated expansion of the Universe. We argue that the latter property is generic in a wide class of models with condensates.

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M. V. Libanov, V. A. Rubakov. 2005-07-28. More about spontaneous Lorentz-violation and infrared modification of gravity. https://doi.org/10.1088/1126-6708%2F2005%2F08%2F001

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