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arXiv · 2606.31035

Nonlinear Landau Collisions Without Collision Tensors

R. Jorge·B. Herfray·C. Vega·V. Zhdankin
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Abstract

Far-from-equilibrium plasmas require nonlinear Coulomb collisions, but direct three-dimensional Hermite discretization of the Landau operator needs an impractical dense tensor. By porting quantum chemistry Coulomb-integral methods, we reduce the six-dimensional integrals to one-center Coulomb moments and separable exponential-sum contractions. This gives a four-order-of-magnitude working-memory reduction and enables nonlinear relaxation tests. Numerical simulations preserve invariants and show that finite-basis linearization changes relaxation and produces a fourfold angular error.

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R. Jorge, B. Herfray, C. Vega, V. Zhdankin. 2026-06-30. Nonlinear Landau Collisions Without Collision Tensors. https://arxiv.org/abs/2606.31035

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