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

By A. Lue, Glenn Starkman. 2004

146 citations recorded by the source corpus.

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.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a96f3aef8c9ae5690717bfe96977d748d9769666

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Citations in the corpus

Brane-World Gravity (2004, background): “Thus, 5D gravity in normal DGP can in principle reduce the bare vacuum energy significantly [371, 298].”
The phenomenology of Dvali–Gabadadze–Porrati cosmologies (2005, methodology): “We need to redo the computation to include the background cosmology, and indeed we will find a cosmology dependent new gravitational force [55,56,34].”
Galileon Cosmology (2009, background): “While decoupled locally, the scalar field can have interesting cosmological effects in the much sparser cosmic environment.”
Null energy condition and superluminal propagation (2005, background): “A no-go theorem valid in ordinary 4D theories may point towards more exotic scenarii, like for instance the Dvali-Gabadadze-Porrati model [6] where an effective w slightly less than −1 for dark energy can be achieved [7, 8], without manifest pathologies [9].”