Quintessence and spontaneous leptogenesis

We propose in this paper a scenario of spontaneous baryogenesis in cosmological models of quintessence by introducing a derivative coupling of the quintessence scalar Q to the baryon current J(B)(mu) or the current of the baryon number minus lepton number J(B-L)(mu). We find that with a dimension-5 operator partial derivative(mu)QJ(B-L)(mu) suppressed by the Planck mass M-pl or the grand unification scale M-GUT, baryon number asymmetry n(B)/ssimilar to10(-10) can be naturally explained via leptogenesis. We study also the isocurvature baryon number fluctuation generated in our model.