  It is shown that the Hubble constant can be derived from the standard
luminosity function of galaxies as well as from a new luminosity function as
deduced from the mass-luminosity relationship for galaxies. An analytical
expression for the Hubble constant can be found from the maximum number of
galaxies (in a given solid angle and flux) as a function of the redshift. A
second analytical definition of the Hubble constant can be found from the
redshift averaged over a given solid angle and flux. The analysis of two
luminosity functions for galaxies brings to four the new definitions of the
Hubble constant. The equation that regulates the Malmquist bias for galaxies is
derived and as a consequence it is possible to extract a complete sample. The
application of these new formulae to the data of the two-degree Field Galaxy
Redshift Survey provides a Hubble constant of $( 65.26 \pm 8.22 ) \mathrm{\ km\
s}^{-1}\mathrm{\ Mpc}^{-1}$ for a redshift lower than 0.042. All the results
are deduced in a Euclidean universe because the concept of space-time curvature
is not necessary as well as in a static universe because two mechanisms for the
redshift of galaxies alternative to the Doppler effect are invoked.
