English

A groupoid rack and spatial surfaces

Geometric Topology 2025-02-25 v5

Abstract

A spatial surface is a compact surface embedded in the 33-sphere. We assume that a spatial surface is oriented and that each connected component of a spatial surface is neither a disk nor without a boundary. A diagram of a spatial surface is a diagram of a spatial trivalent graph that is a spine of the spatial surface. In this paper, we introduce the notion of a groupoid rack, which is used for considering colorings for diagrams of spatial surfaces in order to obtain an invariant of spatial surfaces. Furthermore, we show that a groupoid rack has a universal property on colorings for diagrams of spatial surfaces.

Keywords

Cite

@article{arxiv.2310.06423,
  title  = {A groupoid rack and spatial surfaces},
  author = {Katsunori Arai},
  journal= {arXiv preprint arXiv:2310.06423},
  year   = {2025}
}

Comments

19 pages, 13 figures

R2 v1 2026-06-28T12:45:39.026Z