  I propose that the primordial baryon asymmetry of the universe was induced by
the presence of a non-vanishing antisymmetric field background H_ijk across the
three space dimensions. This background creates a dilute (B-L)-number density
in the universe cancelling the contribution from baryons and leptons. This
situation naturally appears if the U(1)_{B-L} symmetry is gauged and the
corresponding gauge boson gets a Stuckelberg mass by combining with an
antisymmetric field B_ij. All these ingredients are present in D-brane models
of particle physics. None of the Sakharov conditions are required.
