  The baryon-antibaryon asymmetry (excess of matter over antimatter in our
Universe), indicated by observational data from the Cosmic Microwave Background
anisotropies, predictions of primordial Nucleosynthesis, and the absence of
intense radiation from matter-antimatter annihilation, constitutes an unsolved
puzzle in cosmology. Two mechanisms for baryon asymmetry have been proposed as
extensions of the Standard Model of Particle Physics at high energies. They
rely on new couplings involving the baryon number current, one with a scalar
field, called Spontaneous Baryogenesis, and the other with space-time
curvature, named Gravitational Baryogenesis. These two mechanisms are
investigated in the context of many bouncing scenarios, either symmetric or
asymmetric around the bounce. It is shown that the constraints on the free
parameters of these scenarios, imposed to yield the observed baryon-to-entropy
ratio, are mild, already containing the values compatible with other
observational constraints coming from the features of the power spectra of
cosmological perturbations. Hence, realistic bouncing models can yield the
observed baryon-antibaryon asymmetry if one of the two mechanisms proposed
takes place in nature.

General Relativity and Quantum Cosmology