On the Measurement of the Hubble Constant in a Local Low-Density Universe

Astrophysical observations indicate that the ``Local Universe" has arelatively lower matter density ($\Omega_0$) than the predictions of thestandard inflation cosmology and the large-scale motions of galaxies whichprovide a mean mass density to be very close to unity. In such a localunderdense region the Hubble expansion may not be representative of the globalbehaviour. Utilizing an underdense sphere embedded in a flat universe as themodel of our ``Local Universe", we show that the local Hubble constant would be1.2 -- 1.4 times larger than the global value on scale of $\sim80$ Mpc,depending on the variation of $\Omega_0$. This may account for the recentmeasurements of the unpleasantly large Hubble constant of $\sim$80 km/s/Mpcusing the Cepheid variables in the Virgo cluster and the relative distancebetween Virgo and Coma cluster and removes the resulted apparent paradox of theage of our universe.Comment: 9 pages, Latex file, 3 figures available by reques