The Measurement of the Hubble Constant H_0 in the Solar System

Values of the Hubble constant reported to date which are based on measurement of the Sunyaev-Zeldovich (SZ) effect in clusters of galaxies are systematically lower than those derived by other methods (e.g., Cepheid variable stars, or the…

The precise measurement of the Hubble constant H0 is one of the foundations of the current cosmological paradigm. Due to correlations between H0 and the remaining cosmological parameters, a precise measurement of H0 is critical in view of future…

Considerable progress has been made in determining the Hubble constant over the past two decades.We discuss the cosmological context and impor- tance of an accurate measurement of the Hubble constant, focusing on six high-precision…

Establishing accurate extragalactic distances has provided an immense challenge to astronomers since the 1920s. The situation has improved dramatically as better detectors have become available, and as several new, promising techniques have been…

Revised Hipparcos parallaxes for classical Cepheids are analysed together with 10 Hubble Space Telescope (HST)-based parallaxes. In a reddening-free V, I relation we find that the coefficient of logP is the same within the uncertainties in our…

Non-zero neutrino mass would affect the evolution of the Universe in observable ways, and a strong constraint on the mass can be achieved using combinations of cosmological data sets. We focus on the power spectrum of cosmic microwave background…

In Papers I and II from the Megamaser Cosmology Project (MCP), we reported initial observations of water masers in an accretion disk of a supermassive black hole at the center of the galaxy UGC 3789, which gave an angular-diameter distance to the…

The long-standing argument as to whether the Hubble constant is closer to 50 or 100 km s-1Mpc-1 may be due to large local disturbances in galactic motions caused by excess mass in the Coma-Sculptor cloud. Outside this region, a value of 85 to 95 km…

Multiple evidence is compiled and discussed that the large-scale value of the Hubble constant must lie within the range of 45 < H0 < 65. (SECTION: A Debate on The Scale of the Universe)

Ten years ago our team completed the Hubble Space Telescope Key Project on the extragalactic distance scale. Cepheids were detected in some 25 galaxies and used to calibrate four secondary distance indicators that reach out into the expansion field…