Variations of the Cosmic Expansion Field and the Value of the Hubble   Constant
  Four Hubble diagrams are combined to test for the linearity of the cosmic expansion field. The expansion rate, H_0, is found to decrease by ~5% out to 18000km/s. Beyond this distance the mean value of H_0 is close to the value at 10000km/s. The absolute value of H_0 is derived in two different ways. The one leads through Cepheids from HST and blue SNe Ia to H_0=57+/-7 (external error) at 30000km/s. The other uses various distance indicators to the Virgo cluster whose distance can be extended to 10000km/s by means of only relative cluster distances; the result of H_0 is closely the same. Independent distances from purely physical methods (SZ effect, gravitational lenses, and MBW fluctuations) cluster about H_0(cosmic)=58. 
G.A. Tammann (Astron. Inst., Univ. Basel)