Cosmic Degeneracy with Dark Energy Equation of State

Abstract

We discuss a degeneracy between the geometry of the universe and the dark energy equation of state $w_{\mathrm{X}}$ which exists in the power spectrum of the cosmic microwave background. In particular, for the case with $w_{\mathrm{X}}<-1$, this degeneracy has interesting implications to a lower bound on $w_{\mathrm{X}}$ from observations. It is also discussed how this degeneracy can be removed using current observations of type Ia supernovae.

13 pages LaTeX with five [one new] eps figures

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