Upper bounds on signed 2-independence number of graphs

作者：Shan EF^*; Sohn MY; Kang LY

来源：Ars Combinatoria, 2003, 69: 229-239.

• signed 2-independence function
• signed domination
• r-partite graph

A function f: V --> {-1, 1} defined on the vertices of a graph G = (V, E) is a signed 2-independence function if the sum of its function values over any closed neighbourhood is at most one. That is, for every v is an element of V, f (N[v]) less than or equal to 1, where N[v] consists of v and every vertex adjacent to v. The weight of a signed 2-independence function is f(V) = Sigmaf(v), over all vertices v is an element of V. The signed 2-independence number of a graph G, denoted alpha(s)(2)(G), is the maximum weight of a signed 2-independence function of G. In this article, we give some new upper bounds on alpha(s)(2)(G) of G, and establish a sharp upper bound on alpha(s)(2)(G) for an r-partite graph.

• 出版日期2003-10
• 单位上海大学