  The presence of ultra-high energy cosmic rays in the universe in the
pre-ionization epoch enhances significantly H$_2$ kinetics in virialized halos.
It results in more efficient radiative cooling and decreases the lower mass
limit of the first star-forming systems. Consequently, the fraction of baryons
contained in the first luminous objects and their contribution to the
reionization of the universe can significantly increase in comparison with the
standard scenario.
