Supernovae, Lensed CMB and Dark Energy

Abstract

Supernova distance and primary CMB anisotropy measurements provide powerful probes of the dark energy evolution in a flat universe but degrade substantially once curvature is marginalized. We show that lensed CMB polarization power spectrum measurements, accessible to next generation ground based surveys such as SPTpol or QUIET, can remove the curvature degeneracy at a level sufficient for the SNAP and Planck surveys and allow a measurement of sigma(w_p)=0.03, sigma(w_a)=0.3 jointly with sigma(Omega_K)=0.0035. This expectation assumes that the sum of neutrino masses is independently known to better than 0.1 eV. This assumption is valid if the lightest neutrino is assumed to have negligible mass in a normal neutrino mass hierarchy and is potentially testable with upcoming direct laboratory measurements.