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arXiv · 2604.15144

A post-processed higher-order multiscale method for nondivergence-form elliptic equations

Moritz Hauck·Roland Maier·Timo Sprekeler
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Abstract

We study the finite element approximation of linear second-order elliptic partial differential equations in nondivergence form with highly heterogeneous diffusion and drift coefficients. A generalized Cordes condition is imposed to guarantee that a suitably renormalized version of the nondivergence-form differential operator is near the Laplacian. Based on a stabilized symmetric formulation for the gradient that enables the use of $H^1$-conforming approximation spaces, we construct a multiscale method following the methodology of the localized orthogonal decomposition with coarse basis functions tailored to the heterogeneous coefficients. We employ a novel post-processing strategy to obtain higher-order convergence rates, overcoming previous limitations imposed by the low regularity of the load functional. Numerical experiments demonstrate the performance of the method.

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Moritz Hauck, Roland Maier, Timo Sprekeler. 2026-04-16. A post-processed higher-order multiscale method for nondivergence-form elliptic equations. https://arxiv.org/abs/2604.15144

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