English

A Construction of non-degenerate $\mathbb{Z}_{2}$-harmonic functions on $\mathbb{R}^{n}$

Differential Geometry 2025-10-15 v2 Classical Analysis and ODEs

Abstract

We discover an explicit construction of non-degenerate Z2\mathbb{Z}_{2}-harmonic functions on Rn,n3\mathbb{R}^{n},n\geq 3, using a variant of ellipsoidal coordinates on Rn\mathbb{R}^{n}. The branching set of these examples is a codimension-22 ellipsoid, providing the first known family of non-degenerate Z2\mathbb{Z}_{2}-harmonic 11-forms on Rn\mathbb{R}^{n} with compact branching sets. Moreover, the graph of the related Z2\mathbb{Z}_{2}-harmonic one form in TRnT^{*}\mathbb{R}^{n} can be obtained as a certain limit of a specific sequence of Lawlor's necks in Cn=TRn\mathbb{C}^{n}=T^{*}\mathbb{R}^{n}.

Keywords

Cite

@article{arxiv.2503.19286,
  title  = {A Construction of non-degenerate $\mathbb{Z}_{2}$-harmonic functions on $\mathbb{R}^{n}$},
  author = {Dashen Yan},
  journal= {arXiv preprint arXiv:2503.19286},
  year   = {2025}
}

Comments

24 pages. Revised introduction, updated Corollary 4.3 and references