  We introduce a toy model of baryogenesis where our usual visible Universe is
a 3-brane coevolving with a hidden 3-brane in a multidimensional bulk, in an
ekpyrotic-like approach. The visible matter and antimatter sectors are coupled
with the hidden matter and antimatter sectors, breaking the C/CP invariance and
leading to baryogenesis occurring after the quark-gluon era. The issue of
leptogenesis is also discussed. This model complements cosmological approaches
in which dark matter and dark energy could naturally emerge from many-brane
scenarios.
