Recognizing Graphs without Asteroidal Triples

  • Authors:
  • Ekkehard Köhler

  • Affiliations:
  • -

  • Venue:
  • WG '00 Proceedings of the 26th International Workshop on Graph-Theoretic Concepts in Computer Science
  • Year:
  • 2000

Quantified Score

Hi-index 0.00

Visualization

Abstract

We consider the problem of recognizing AT-free graphs. Although there is a simple O(n3) algorithm, no faster method for solving this problem had been known. Here we give three different algorithms which have a better time complexity for graphs which are sparse or have a sparse complement; in particular we give algorithms which recognize AT-free graphs in O(nm + n2), O(m3/2 + n2), and O(n2.82 + nm). In addition we give a new characterization of graphs with bounded asteroidal number by the help of the knotting graph, a combinatorial structure which was introduced by Gallai for considering comparability graphs.