Speaker: Prof. Vadim Cheianov, Instituut-Lorentz, Leiden UniversityTitle: Damping rate of the axial charge in an ultra-relativistic QED plasma
Abstract. Ultra-relativistic limit in a QED plasma corresponds to temperatures much greater than the electron mass. In this limit it is natural to approximate electrons as massless particles, which, in particular, implies the existence of a new approximately conserved quantity - the axial charge. The approximate conservation of the axial charge has important ramifications for the hydrodynamics of the plasma, leading to macroscopic physical effects, for example the inverse magnetic cascade, and more generally, chiral magneto-hydrodynamics (chi-MHD). To understand the applicability of chi-MHD one needs to know the rate of decay of the axial charge due to the presence of a small electron mass. In this talk I will show how this problem was addressed in the past and why the axial charge relaxation rates given in literature are off by at least two orders of magnitude. I will give the correct expression for the axial charge relaxation rate and briefly discuss this result's implications for physics.
Venue: online (zoom). For a zoom link please contact Oleg Lychkovskiy (lychkovskiy(at)gmail.com).