English

On powers of interval graphs and their orders

Combinatorics 2015-11-10 v2

Abstract

It was proved by Raychaudhuri in 1987 that if a graph power Gk1G^{k-1} is an interval graph, then so is the next power GkG^k. This result was extended to mm-trapezoid graphs by Flotow in 1995. We extend the statement for interval graphs by showing that any interval representation of Gk1G^{k-1} can be extended to an interval representation of GkG^k that induces the same left endpoint and right endpoint orders. The same holds for unit interval graphs. We also show that a similar fact does not hold for trapezoid graphs.

Keywords

Cite

@article{arxiv.1505.03459,
  title  = {On powers of interval graphs and their orders},
  author = {Florent Foucaud and Reza Naserasr and Aline Parreau and Petru Valicov},
  journal= {arXiv preprint arXiv:1505.03459},
  year   = {2015}
}

Comments

4 pages, 1 figure. It has come to our attention that Theorem 1, the main result of this note, follows from earlier results of [G. Agnarsson, P. Damaschke and M. M. Halldorsson. Powers of geometric intersection graphs and dispersion algorithms. Discrete Applied Mathematics 132(1-3):3-16, 2003]. This version is updated accordingly

R2 v1 2026-06-22T09:33:39.457Z