English

Integrability of the Brouwer degree for irregular arguments

Classical Analysis and ODEs 2016-09-14 v3

Abstract

We prove that the Brouwer degree deg(u,U,)\mathrm{deg}(u,U,\cdot) for a function uC0,α(U;Rn)u\in C^{0,\alpha}( U;\mathbb{R}^n) is in Lp(Rn)L^p(\mathbb{R}^n) if 1p<nαd1\leq p<\frac{n\alpha}d, where URnU\subset \mathbb{R}^n is open and bounded and dd is the box dimension of U\partial U. This is supplemented by a theorem showing that ujuu_j\to u in C0,α(U;Rn)C^{0,\alpha}(U;\mathbb{R}^n) implies deg(uj,U,)deg(u,U,)\mathrm{deg}(u_j,U,\cdot)\to \mathrm{deg}(u,U,\cdot) in Lp(Rn)L^p(\mathbb{R}^n) for the parameter regime 1p<nαd1\leq p<\frac{n\alpha}d, while there exist convergent sequences ujuu_j\to u in C0,α(U;Rn)C^{0,\alpha}(U;\mathbb{R}^n) such that deg(uj,U,)Lp\|\mathrm{deg}(u_j,U,\cdot)\|_{L^p}\to \infty for the opposite regime p>nαdp>\frac{n\alpha}d.

Keywords

Cite

@article{arxiv.1508.06858,
  title  = {Integrability of the Brouwer degree for irregular arguments},
  author = {Heiner Olbermann},
  journal= {arXiv preprint arXiv:1508.06858},
  year   = {2016}
}

Comments

29 pages, 7 figures; statement and proof of Theorem 1.1 corrected, acknowledgments amended

R2 v1 2026-06-22T10:42:52.837Z