Probing the dark side: Constraints on the dark energy equation of state from CMB, large scale structure and Type Ia supernovae

By S. Hannestad, E. Mortsell. 2002

161 citations recorded by the source corpus.

We have reanalyzed constraints on the equation of state parameter, ${w}_{Q}\ensuremath{\equiv}P/\ensuremath{\rho},$ of the dark energy, using several cosmological data sets and relaxing the usual constraint ${w}_{Q}g~\ensuremath{-}1.$ We find that combining cosmic microwave background, large scale structure, and type Ia supernova data yields a nontrivial lower bound on ${w}_{Q}.$ At 95.4% confidence we find, assuming a flat geometry of the universe, a bound of $\ensuremath{-}2.68l{w}_{Q}l\ensuremath{-}0.78$ if ${w}_{Q}$ is taken to be a completely free parameter. Reassuringly we also find that the constraint ${w}_{Q}g~\ensuremath{-}1$ does not significantly bias the overall allowed region for ${w}_{Q}.$ When this constraint is imposed the 95.4% confidence bound is $\ensuremath{-}1l~{w}_{Q}l\ensuremath{-}0.71.$ Also, a pure cosmological constant $(w=\ensuremath{-}1)$ is an excellent fit to all available data. Based on simulations of future data from the Planck CMB experiment and the SNAP and SNfactory supernova experiments we estimate that it will be possible to constrain ${w}_{Q}$ at the 5% level in the future.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6d6790d5b76609dfc991a4a263f10be31d6f7d55

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

The dS/CFT Correspondence and the Big Smash (2001, methodology): “The current data are summarized in Figure 4 of [4].”
Cosmological parameters from supernova observations: A critical comparison of three data sets (2003, background): “…of exotic forms of energy densities – possibly scalar fields with negative kinetic energies [such models are explored, for example, in Caldwell (2002); Hannestad & Mörtsell (2002); Carroll, Hoffman, & Trodden (2003); Caldwell, Kamionkowski, & Weinberg (2003); Melchiorri et al. (2003); Singh,…”
FRIEDMANN–ROBERTSON–WALKER BRANE COSMOLOGICAL EQUATIONS FROM THE FIVE-DIMENSIONAL BULk (A)dS BLACK HOLE (2002, result): “Moreover, as a result of acceleration it looks that the cosmology with negative density energy and negative pressure does not seem to contradict to the astronomical data (for recent initial steps to study such cosmology, see [ 2 ]).”