Matter-antimatter asymmetry in generalized coupling theories

We explore the gravitational baryogenesis paradigm in the homogeneous and isotropic cosmology of generalized coupling gravity and, in particular, of the so-called Minimal Exponential Measure Model (MEMe). We show that, also in this theory, the time derivative of the Ricci scalar couples with matter currents and can preserve an unbalance in the baryon-antibaryon number beyond thermal equilibrium. Using the current bounds on the ratio of baryon number to entropy density, we can considerably improve the known constraints on the parameter q that characterizes the MEMe model. This estimate also allows us to draw stringent constraints on the spatial curvature of the cosmological model.