Fluid moments of the Landau collision operator

TL;DR

This paper introduces a new method to accurately compute fluid moments of the nonlinear Landau collision operator, enhancing plasma fluid models for weakly collisional and strong flow regimes.

Contribution

It presents an integral identity and a systematic method for exact computation of fluid moments, improving the modeling of Coulomb collisions in plasma physics.

Findings

Provides exact expressions for fluid moments of the Landau operator

Extends fluid models to weakly collisional regimes

Offers a rigorous computational framework

Abstract

One important problem in plasma physics is the lack of an accurate and complete description of Coulomb collisions in associated fluid models. To shed light on the problem, this Letter introduces an integral identity involving the multi-dimensional Hermite tensor polynomials and presents a method for computing exact expressions for the fluid moments of the nonlinear Landau collision operator. The proposed methodology provides a systematic and rigorous means of extending the validity of fluid models that have an underlying inverse-square force particle dynamics to weakly collisional and strong flow regimes.