Speaker
Nikos Mavromatos
(University of London (GB))
Description
I will discuss ways by means of which CPT in early epochs of the Universe may be violated, leading initially to an asymmetry in the populations of leptons versus antileptons (Leptogenesis), which may then be communicated to the baryon sector (via Baryon-Lepton-number (B-L) conserving processes) to produce the observed Baryon Asymmetry (Baryogenesis). These include: space-time curvature/spin coupling in non-standard (Lorentz-violating) geometries of the early Universe, such as axisymmetric black-hole geometries and certain Bianchi cosmologies or propagation in stochastically fluctuating space-time geometries of Finsler type, geometries with Kalb-Ramond torsion backgrounds and D-brane defect foam. In all such models CPT Violation occurs as a result of different dispersion relations induced between particles and antiparticles in the above backgrounds. In the D-brane (quantum-gravity) foam model there is a preferential role of neutrinos in coupling with the foam, which is due to electric charge conservation for specifically stringy reasons. Such models may then serve as ways of generating baryongenesis from leptogenesis without the need for extra sources of CP violation.
Author
Nikos Mavromatos
(University of London (GB))
