  The $\Lambda$CDM scenario to form galaxies encounters many problems when
confronted with observations, namely the prediction of dark matter cusps in all
galaxies, and in particular in dwarf irregulars, dominated by dark matter, or
the low angular momentum and consequent small size of galaxy disks, or the high
predicted number of small systems. We will consider the hypothesis that the
baryonic dark matter could be in the form of gas and could be continuously
involved in the galaxy formation scenario. Through cold gas accretion all along
a galaxy life, angular momentum could be increased, galaxy disks could be more
dominated by baryons than previously thought, and small systems could merge
more frequently.
