English

Graphs whose indecomposability graph is 2-covered

Combinatorics 2013-08-15 v1

Abstract

Given a graph G=(V,E)G=(V,E), a subset XX of VV is an interval of GG provided that for any a,bXa, b\in X and xVX x\in V \setminus X, {a,x}E\{a,x\}\in E if and only if {b,x}E\{b,x\}\in E. For example, \emptyset, {x}(xV)\{x\}(x\in V) and VV are intervals of GG, called trivial intervals. A graph whose intervals are trivial is indecomposable; otherwise, it is decomposable. According to Ille, the indecomposability graph of an undirected indecomposable graph GG is the graph I(G)\mathbb I(G) whose vertices are those of GG and edges are the unordered pairs of distinct vertices {x,y}\{x,y\} such that the induced subgraph G[V{x,y}]G[V \setminus \{x,y\}] is indecomposable. We characterize the indecomposable graphs GG whose I(G)\mathbb I(G) admits a vertex cover of size 2.

Keywords

Cite

@article{arxiv.1308.3074,
  title  = {Graphs whose indecomposability graph is 2-covered},
  author = {Rim Ben Hamadou and Imed Boudabbous},
  journal= {arXiv preprint arXiv:1308.3074},
  year   = {2013}
}

Comments

31 pages, 5 figures

R2 v1 2026-06-22T01:09:08.022Z