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<title>Rosivaldo Gonçalves — Neckpinch</title><link>https://neckpinch.com/authors/rosivaldo-goncalves/</link><description>New arXiv papers by Rosivaldo Gonçalves, from Neckpinch</description>
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<item><title>Anisotropic Parabolic Obstacle Problems and the Stefan Problem: Regularity of the Evolving Free Boundary</title><link>https://neckpinch.com/papers/2606.29058/</link><guid isPermaLink="false">arxiv:2606.29058</guid><pubDate>Sat, 27 Jun 2026 00:00:00 GMT</pubDate><description>Ezequiel Barbosa, Rosivaldo Gonçalves, Luan de Figueiredo — We study a parabolic obstacle problem for surfaces evolving by anisotropic mean curvature flow subject to an obstacle constraint. Given a convex obstacle and initial data, we seek an evolving surface minimizing an anisotropic energy functional while remaining above the obstacle; as a special case, this framework includes the anisotropic Stefan problem, where the free boundary represents a phase transition interface with direction-dependent surface tension. The central tool is the Cahn–Hoffman transform S(x) = A^(−1/2)x, which maps the Wulff ellipsoid x : x^T A⁻¹x ≤ 1\ to the Euclidean unit ball and converts the anisotropic problem into an equivalent isotropic one with a generalized Robin-type condition on the free boundary. We prove optimal regularity of the solution (C^(1,α) in space and C^(0,α/2) in time up to the free boundary) and C^(1,α)-regularity of the evolving free boundary at non-degenerate points. The parabolic Hausdorff dimension of the space-time singular set is shown to be at most n − 1.</description><category>Mean curvature flow</category><category>Anisotropic &amp; nonlocal flows</category><category>Free boundary &amp; capillary</category></item>
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