Quantitative Closure Analysis toward Ideal Fluids

Gi-Chan Bae; Chanwoo Kim

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arXiv · 2603.14671

Quantitative Closure Analysis toward Ideal Fluids

Gi-Chan Bae·Chanwoo Kim

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Abstract

We establish the incompressible low--Mach/high--Reynolds limit for the Boltzmann equation for a broad class of initial data, without recourse to any asymptotic expansion. Exploiting the local Maxwellian manifold and the macro--micro decomposition in a new quasi-linear analysis, we derive quantitative estimates for the purely microscopic fluctuation, as well as bounds for the kinetic vorticity and the entropic fluctuation in terms of the initial data. As a consequence, in two space dimensions, the rescaled velocity and temperature converge to a global solution of the incompressible Euler equations coupled to a transported temperature, within the frameworks of DiPerna--Lions--Majda and Delort.

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Gi-Chan Bae, Chanwoo Kim. 2026-03-15. Quantitative Closure Analysis toward Ideal Fluids. https://arxiv.org/abs/2603.14671

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