• DOI:10.1103/PhysRevD.70.101501
• Corpus ID: 8297754

How a brane cosmological constant can trick us into thinking that w<-1

@article{Lue2004HowAB,
  title={How a brane cosmological constant can trick us into thinking that w<-1},
  author={Arthur Lue and Glenn D Starkman},
  journal={Physical Review D},
  year={2004},
  volume={70},
  pages={101501}
}

• A. Lue, G. Starkman
• Published 12 August 2004
• Physics
• Physical Review D

Observations exploring the contemporary cosmic acceleration have sparked interest in dark energy models possessing equations of state with $wl\ensuremath{-}1$. We review how the cosmic expansion history of a Dvali-Gabadadze-Porrati (DGP) braneworld model with a standard brane cosmological constant can mimic that of ordinary 4D gravity with $wl\ensuremath{-}1$ ``phantom'' dark energy for observationally relevant redshifts. We reinterpret the effective phantom nature of the dark energy as arising from dynamical-screening of the brane cosmological constant in DGP. This unusual variety of expansion history is thus possible without violating the null-energy condition, without ghosts and without any big rip, in a model which seems no more contrived than most evolving dark energy models. We indicate ways by which one may observationally test this effective $wl\ensuremath{-}1$ possibility, and differentiate it from ordinary phantom dark energy.