Partial regularity for the optimal $p$-compliance problem with length penalization
Bohdan Bulanyi
TL;DR
The paper analyzes the optimal $p$-compliance problem with a length penalization in a bounded domain, proving that minimizers cannot contain loops and are $C^{1,\alpha}$-regular at $\mathcal{H}^{1}$-a.e. points of the free set inside the domain for all $p\in(N-1,\infty)$. The authors develop a higher-dimensional regularity theory by combining a decay of the $p$-energy under flatness control with an $\varepsilon$-regularity framework, and they introduce a localized energy-difference bound, capacity-based regularity tools, and a density control mechanism to handle the codimension-$N-1$ free boundary. A key technical contribution is the development of barrier constructions and compactness arguments to obtain energy decay and to propagate flatness through scales, culminating in a partial regularity result that extends prior 2D results to any $N\ge2$ and $p> N-1$. The work advances the understanding of free boundary problems with length penalization in the nonlinear $p$-Laplacian setting, with implications for shape optimization and the structure of optimal networks.
Abstract
We establish a partial $C^{1,α}$ regularity result for minimizers of the optimal $p$-compliance problem with length penalization in any spatial dimension $N\geq 2$, extending some of the results obtained in [Chambolle-Lamboley-Lemenant-Stepanov 17], [Bulanyi-Lemenant 20]. The key feature is that the $C^{1,α}$ regularity of minimizers for some free boundary type problem is investigated with a free boundary set of codimension $N-1$. We prove that every optimal set cannot contain closed loops, and it is $C^{1,α}$ regular at $\mathcal{H}^{1}$-a.e. point for every $p\in (N-1,+\infty)$.
