Baryogenesis in Lorentz-violating gravity theories

Lorentz-violating theories of gravity typically contain constrained vector fields. We show that the lowestorder coupling of such vectors to U(1)-symmetric scalars can naturally give rise to baryogenesis in a manner akin to the Affleck-Dine mechanism. We calculate the cosmology of this new mechanism, demonstrating that a net B -Lcan be generated in the early Universe, and that the resulting baryon-tophoton ratio matches that which is presently observed. We discuss constraints on the model using solar system and astrophysical tests of Lorentz violation in the gravity sector. Generic Lorentz-violating theories can give rise to the observed matter-antimatter asymmetry without violating any current bounds. (C) 2017 The Author(s). Published by Elsevier B.V.