New Constraints on the Early Expansion History
  Cosmic microwave background measurements have pushed to higher resolution,
lower noise, and more sky coverage. These data enable a unique test of the
early universe's expansion rate and constituents such as effective number of
relativistic degrees of freedom and dark energy. Using the most recent data
from Planck and WMAP9, we constrain the expansion history in a model
independent manner from today back to redshift z=10^5. The Hubble parameter is
mapped to a few percent precision, limiting early dark energy and extra
relativistic degrees of freedom within a model independent approach to 2-16%
and 0.71 equivalent neutrino species respectively (95% CL). Within dark
radiation, barotropic aether, and Doran-Robbers models, the early dark energy
constraints are 3.3%, 1.9%, 1.2% respectively.
