Zero-relaxation-time limits in the hydrodynamic equations for plasmas revisited

Abstract.

A rigorous proof of the zero-relaxation-time limits in the hydrodynamic equations for plasmas is given. The equations consist of the Euler equations for the electrons and/or ions coupled with a linear or nonlinear Poisson equation. The proof is based on high energy estimates for the Euler equations and appropriate compactness arguments. The theorem is valid for all adiabatic states for both electrons and ions and thus improves our previous results [9].