The “gravitational baryogenesis” scenario is extended to generate both baryon and dark matter asymmetries in the matter dominated era corresponding to post-inflationary reheating. A minimal extension requires a singlet fermion $X$ for dark matter and a singlet scalar $S$. With two or more hidden sector fermions, the scenario can lead to nucleon decay into dark matter with a lifetime of order ${10}^{34–36}\mathrm{yr}$, which is relevant for current or future experiments. The correct multicomponent relic density can be obtained if dark matter fermions couple to a sub-GeV vector boson that weakly interacts with the standard model through mixing. The typical inflationary scale in the scenario is of order ${10}^{16}\mathrm{GeV}$ which suggests that tensor mode perturbations could potentially be within observational reach.

• Received 16 September 2013

DOI:https://doi.org/10.1103/PhysRevD.88.095004