Relativistic plasma viscosity of the Burnett kind.

Hydrodynamic equations to describe relativistic and ultrarelativistic plasma dynamics were obtained by Dzhavakhishvili and Tsintsadze [Sov. Phys. JETP 37, 666 (1973)] using the Chapman and Enskog scheme to solve the relativistic kinetic equations for the different plasma species. This approach leads to a representation of the particle viscosities in the Navier-Stokes form and, therefore, some relevant physical processes, such as the Burnett type of particle viscosity, cannot be properly dealt with in this scheme. In this paper we employ the extended Grad method to derive hydrodynamic equations which include ultrarelativistic viscosities of the Burnett type, i.e., viscosities that depend not only on derivatives of the particle macroscopic velocities but also on derivatives of particle heat fluxes.