English

Critical and Maximum Independent Sets of a Graph

Discrete Mathematics 2015-06-02 v1 Combinatorics

Abstract

Let G be a simple graph with vertex set V(G). A subset S of V(G) is independent if no two vertices from S are adjacent. By Ind(G) we mean the family of all independent sets of G while core(G) and corona(G) denote the intersection and the union of all maximum independent sets, respectively. The number d(X)= |X|-|N(X)| is the difference of the set of vertices X, and an independent set A is critical if d(A)=max{d(I):I belongs to Ind(G)} (Zhang, 1990). Let ker(G) and diadem(G) be the intersection and union, respectively, of all critical independent sets of G (Levit and Mandrescu, 2012). In this paper, we present various connections between critical unions and intersections of maximum independent sets of a graph. These relations give birth to new characterizations of Koenig-Egervary graphs, some of them involving ker(G), core(G), corona(G), and diadem(G).

Keywords

Cite

@article{arxiv.1506.00255,
  title  = {Critical and Maximum Independent Sets of a Graph},
  author = {Adi Jarden and Vadim E. Levit and Eugen Mandrescu},
  journal= {arXiv preprint arXiv:1506.00255},
  year   = {2015}
}

Comments

12 pages, 9 figures. arXiv admin note: substantial text overlap with arXiv:1407.7368