Cover-incomparability graphs and chordal graphs

Autor: Manoj Changat, Joseph Mathews, Antony Mathews, Boštjan Brešar, Tanja Gologranc
Rok vydání: 2010
Předmět:
Zdroj: Discrete Applied Mathematics. 158(16):1752-1759
ISSN: 0166-218X
DOI: 10.1016/j.dam.2010.07.001
Popis: The problem of recognizing cover-incomparability graphs (i.e. the graphs obtained from posets as the edge-union of their covering and incomparability graph) was shown to be NP-complete in general [J. Maxová, P. Pavlíkova, A. Turzík, On the complexity of cover-incomparability graphs of posets, Order 26 (2009) 229–236], while it is for instance clearly polynomial within trees. In this paper we concentrate on (classes of) chordal graphs, and show that any cover-incomparability graph that is a chordal graph is an interval graph. We characterize the posets whose cover-incomparability graph is a block graph, and a split graph, respectively, and also characterize the cover-incomparability graphs among block and split graphs, respectively. The latter characterizations yield linear time algorithms for the recognition of block and split graphs, respectively, that are cover-incomparability graphs.
Databáze: OpenAIRE