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arXiv · 2203.13177

A monotonicity formula for minimizers of the Mumford-Shah functional in 2d and a sharp lower bound on the energy density

Julian Fischer
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Abstract

We establish a new monotonicity formula for minimizers of the Mumford-Shah functional in planar domains. Our formula follows the spirit of Bucur-Luckhaus, but works with the David-Léger entropy instead of the energy. Interestingly, this allows for a sharp truncation threshold. In particular, our monotonicity formula is able to discriminate between points at a $C^1$ interface and any other type of singularity in terms of a finite gap in the entropy. As a corollary, we prove an optimal lower bound on the energy density around any nonsmooth point for minimizers of the Mumford-Shah functional.

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Julian Fischer. 2022-03-24. A monotonicity formula for minimizers of the Mumford-Shah functional in 2d and a sharp lower bound on the energy density. https://arxiv.org/abs/2203.13177

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