English

$Z$-oriented triangulations of surfaces

Combinatorics 2020-02-07 v3

Abstract

The main objects of the paper are zz-oriented triangulations of connected closed 22-dimensional surfaces. A zz-orientation of a map is a minimal collection of zigzags which double covers the set of edges. We have two possibilities for an edge -- zigzags from the zz-orientation pass through this edge in different directions (type I) or in the same direction (type II). Then there are two types of faces in a triangulation: the first type is when two edges of the face are of type I and one edge is of type II and the second type is when all edges of the face are of type II. We investigate zz-oriented triangulations with all faces of the first type (in the general case, any zz-oriented triangulation can be shredded to a zz-oriented triangulation of such type). A zigzag is homogeneous if it contains precisely two edges of type I after any edge of type II. We give a topological characterization of the homogeneity of zigzags; in particular, we describe a one-to-one correspondence between zz-oriented triangulations with homogeneous zigzags and closed 22-cell embeddings of directed Eulerian graphs in surfaces. At the end, we give an application to one type of the zz-monodromy.

Keywords

Cite

@article{arxiv.2001.02626,
  title  = {$Z$-oriented triangulations of surfaces},
  author = {Adam Tyc},
  journal= {arXiv preprint arXiv:2001.02626},
  year   = {2020}
}

Comments

One of the results of this preprint (Proposition 3) can be found in arXiv:1902.10788. Since I am a single author of this statement, I rewrite this result to make the material self-completed. The remaining two authors of arXiv:1902.10788 do not have any objections and do not plan to include this result in their forthcoming paper. arXiv admin note: substantial text overlap with arXiv:1902.10788

R2 v1 2026-06-23T13:06:10.240Z