Title

The (1,2)-Step Competition Graph of a Tournament

Document Type

Article

Publication Date

1-28-2011

Source Publication

Discrete Applied Mathematics

Abstract

The competition graph of a digraph, introduced by Cohen in 1968, has been extensively studied. More recently, in 2000, Cho, Kim, and Nam defined the m-step competition graph. In this paper, we offer another generalization of the competition graph. We define the (1,2)-step competition graph of a digraph D, denoted C1,2(D), as the graph on V(D) where {x,y}∈E(C1,2(D)) if and only if there exists a vertex z≠x,y, such that either dD−y(x,z)=1 and dD−x(y,z)≤2 or dD−x(y,z)=1 and dD−y(x,z)≤2. In this paper, we characterize the (1,2)-step competition graphs of tournaments and extend our results to the (i,k)-step competition graph of a tournament.

Comments

Discrete Applied Mathematics, Volume 159, Issues 2–3, pp 100–103 (January, 2011). DOI: 10.1016/j.dam.2010.10.008