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arXiv · 2607.22064

Convergence of a two-relaxation-times kinetic approximation towards the solution of a scalar conservation law

Denise Aregba-Driollet·Thomas Bellotti
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Abstract

We introduce a two-relaxation-times (TRT) kinetic approximation for scalar non-linear conservation laws in one space dimension, addressing the convergence of relaxation approximations to entropy solutions. The proposed TRT system, derived from a lattice Boltzmann scheme, generalizes the classical BGK (single-relaxationtime) framework. Requesting quasi-monotonicity of the relaxation operator, we establish global existence of solutions for the TRT system and prove their convergence, using a lattice Boltzmann scheme, to the entropy solution of the original conservation law as the relaxation times vanish. Moreover, we propose a qualitative analysis, clarifying the role of relaxation parameters and equilibrium coefficients in shaping solutions, via Chapman-Enskog expansion and looking at travelling wave solutions.

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Denise Aregba-Driollet, Thomas Bellotti. 2026-07-24. Convergence of a two-relaxation-times kinetic approximation towards the solution of a scalar conservation law. https://arxiv.org/abs/2607.22064

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