Quintessence and Spontaneous Leptogenesis

Abstract

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 ${\partial }_{\mu }Q{J}_{B-L}^{\mu }$ suppressed by the Planck mass $M_{pl}$ or the Grand Unification Scale $M_{GUT}$, baryon number asymmetry $n_B/s\sim 10^{-10}$ can be naturally explained {\it via} leptogenesis. We study also the isocurvature baryon number fluctuation generated in our model.

Comments: 7pages,1figure