Séminaire de Physique ThéoriqueHydrodynamic Excitations From Chiral Kinetic Theory and the Hydrodynamic Frames
Navid Abbasi (Institut de recherche en sciences fondamentales, Tehran)
Thursday 07 June 2018 14:00 - Tours - Salle 1180 (Bât E2)
The hydrodynamic limit in a weakly coupled system is equivalent with the long wave-length limit of the perturbations in the system, in the kinetic description. In this talk, I will consider a system of weakly interacting chiral fermions in presence of a background magnetic field. I will first show that Lorentz invariance obliges to modify the definition of the momentum current in phase space, when the system is out of equilibrium. Then by using the modified momentum current, I will derive the spectrum of hydro modes in the system in the frame work of chiral kinetic theory. Interestingly, the result does not coinside with the same spectrum obtained from the chiral hydrodynamics computations in the Landau-Lifshitz frame. By giving evidence from three different directions, I will motivate that the discrepancy is related to the ambiguity in defining the fluid velocity out of equilibrium.