Baryon Asymmetry of Universe: View from Superfluid 3He

The origin of the excess of matter over antimatter in our Universe remains one of the fundamental problems. Dynamical baryogenesis in the process of the broken symmetry electroweak transition in the expanding Universe is the widely discussed model where the baryonic asymmetry is induced by the quantum chiral anomaly. We discuss the modelling of this phenomenon in superfluid3He and superconductors where the chiral anomaly is realized in the presence of quantized vortex, which introduces nodes into the energy spectrum of the fermionic quasiparticles. The spectral flow of fermions through the nodes during the vortex motion leads to the creation of fermionic charge from the superfluid vacuum and to transfer of the superfluid linear momentum into the heat bath, thus producing an extra force on the vortex, which in some cases compensates the Magnus force. This spectral-flow force was calculated 20 years ago by Kopnin and Kravtsov for s-wave superconductors, but only recently was it measured in a broad temperature range in Manchester experiments on rotating superfluid3He. The ”momentogenesis” observed in3He is analogous to the dynamical production of baryons by cosmic strings. Some other possible scenaria of baryogenesis related to superfluid3He are discussed.