Attractor scenarios and superluminal signals in k-essence cosmology

@article{Kang2007AttractorSA,
  title={Attractor scenarios and superluminal signals in k-essence cosmology},
  author={Jin U. Kang and Vitaly Vanchurin and Sergei Winitzki},
  journal={Physical Review D},
  year={2007},
  volume={76},
  pages={083511}
}
Cosmological scenarios with k-essence are invoked in order to explain the observed late-time acceleration of the Universe. These scenarios avoid the need for fine-tuned initial conditions (the 'coincidence problem') because of the attractorlike dynamics of the k-essence field {phi}. It was recently shown that all k-essence scenarios with Lagrangians p=L(X){phi}{sup -2}, where X{identical_to}(1/2){phi}{sub ,{mu}}{phi}{sup ,{mu}}, necessarily involve an epoch where perturbations of {phi… 

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