On $C^{1,\alpha}$-regularity for critical points of a geometric obstacle-type problem
Abstract
We consider critical points of the geometric obstacle problem on vectorial maps $u: \mathbb{B}^2 \subset \mathbb{R}^2 \to \mathbb{R}^N$ \[ \int_{\mathbb{B}^2} |\nabla u|^2 \quad \mbox{subject to $u \in \mathbb{R}^N \backslash \mathbb{B}^N(0)$}. \] Our main result is $C^{1,\alpha}$-regularity for any $\alpha < 1$. Technically, we split the map $u=\lambda v$, where $v: \mathbb{B}^2 \to \mathbb{S}^{N-1}$ is the vectorial component and $\lambda = |u|$ the scalar component measuring the distance to the origin. While $v$ satisfies a weighted harmonic map equation with weight $\lambda^2$, $\lambda$ solves the obstacle problem for \[ \int_{\mathbb{B}^2} |\nabla \lambda|^2+\lambda^2 |\nabla v|^2, \quad \mbox{subject to $\lambda \geq 1$}. \] where $|\nabla v|^2 \in L^1(\mathbb{B}^2)$. We then play ping-pong between the increases in the regularity of $\lambda$ and $v$ to obtain finally the $C^{1,\alpha}$-result.
- Publication:
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arXiv e-prints
- Pub Date:
- November 2018
- DOI:
- 10.48550/arXiv.1811.00829
- arXiv:
- arXiv:1811.00829
- Bibcode:
- 2018arXiv181100829K
- Keywords:
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- Mathematics - Analysis of PDEs
- E-Print:
- J. Math. Pures Appl. 2020