English

Edge Partitions of Complete Geometric Graphs (Part 1)

Combinatorics 2021-12-20 v2 Computational Geometry

Abstract

In this paper, we disprove the long-standing conjecture that any complete geometric graph on 2n2n vertices can be partitioned into nn plane spanning trees. Our construction is based on so-called bumpy wheel sets. We fully characterize which bumpy wheels can and in particular which \emph{cannot} be partitioned into plane spanning trees (or even into arbitrary plane \emph{subgraphs}), including a complete description of all possible partitions (into plane spanning trees). Furthermore, we show a sufficient condition for \emph{generalized wheels} to not admit a partition into plane spanning trees, and give a complete characterization when they admit a partition into plane spanning double stars.

Keywords

Cite

@article{arxiv.2108.05159,
  title  = {Edge Partitions of Complete Geometric Graphs (Part 1)},
  author = {Johannes Obenaus and Joachim Orthaber},
  journal= {arXiv preprint arXiv:2108.05159},
  year   = {2021}
}