English

When is the Direct Product of Generalized Mycielskians a Cover Graph?

Combinatorics 2012-02-28 v1

Abstract

A graph is said to be a cover graph if it is the underlying graph of the Hasse diagram of a finite partially ordered set. The direct product G X H of graphs G and H is the graph having vertex set V(G) X V(H) and edge set E(G X H) = {(g_i,h_s)(g_j,h_t): g_ig_j belongs to E(G) and h_sh_t belongs to E(H)}. We prove that the direct product M_m(G) X M_n(H) of the generalized Mycielskians of G and H is a cover graph if and only if G or H is bipartite.

Keywords

Cite

@article{arxiv.1202.5720,
  title  = {When is the Direct Product of Generalized Mycielskians a Cover Graph?},
  author = {Hsin-Hao Lai and Ko-Wei Lih and Chen-Ying Lin and Li-Da Tong},
  journal= {arXiv preprint arXiv:1202.5720},
  year   = {2012}
}

Comments

9 pages, accepted by Ars Combinatoria on May 13, 2010