  We use the Simon, Verde, & Jimenez (2005) determination of the redshift
dependence of the Hubble parameter to constrain cosmological parameters in
three dark energy cosmological models. We consider the standard $\Lambda$CDM
model, the XCDM parameterization of the dark energy equation of state, and a
slowly rolling dark energy scalar field with an inverse power-law potential.
The constraints are restrictive, consistent with those derived from Type Ia
supernova redshift-magnitude data, and complement those from galaxy cluster gas
mass fraction versus redshift data.
