English

Blockers for simple Hamiltonian paths in convex geometric graphs of odd order

Combinatorics 2018-06-07 v1

Abstract

Let G be a complete convex geometric graph, and let F be a family of subgraphs of G. A blocker for F is a set of edges, of smallest possible size, that has an edge in common with every element of F. In [C. Keller and M. A. Perles, Blockers for simple Hamiltonian paths in convex geometric graphs of even order, Disc. Comput. Geom., 60(1) (2018), pp. 1-8] we gave an explicit description of all blockers for the family of simple (i.e., non-crossing) Hamiltonian paths (SHPs) in G in the `even' case |V(G)|=2m. It turned out that all the blockers are simple caterpillar trees of a certain class. In this paper we give an explicit description of all blockers for the family of SHPs in the `odd' case |V(G)|=2m-1. In this case, the structure of the blockers is more complex, and in particular, they are not necessarily simple. Correspondingly, the proof is more complicated.

Keywords

Cite

@article{arxiv.1806.02178,
  title  = {Blockers for simple Hamiltonian paths in convex geometric graphs of odd order},
  author = {Chaya Keller and Micha A. Perles},
  journal= {arXiv preprint arXiv:1806.02178},
  year   = {2018}
}

Comments

22 pages, 12 figures