Estimation of the Hubble Constant and Constraint on Descriptions of Dark Energy

Understand

Joint analysis of Cosmic Microwave Background, Baryon Acoustic Oscillation, and supernova data has enabled precision estimation of cosmological parameters.

• New programs will push to 1% uncertainty in the dark energy equation of state and tightened constraint on curvature, requiring close attention to systematics.
• Direct 1% measurement of the Hubble constant (H0) would provide a new constraint.
• It can be obtained without overlapping systematics directly from recessional velocities and geometric distance estimates for galaxies via the mapping of water maser emission that traces the accretion disks of nuclear black holes.