Strong Edge Criticality for Cardinality-Redundance in Graphs
نویسندگان
1 Department of Mathematics, Shahed University, Tehran, I. R. Iran
2 Department of Mathematics, Shahed University, Tehran, I. R. Iran
doi
10.22052/mir.2025.256792.1518چکیده
A vertex $v$ in a graph $G$ is said to be over-dominated by a subset $S$ of vertices of $G$ if $|N[v]\cap S|\geq 2$. The cardinality--redundance of $S$, which we denote by $CR(S)$, is the number of vertices of $G$ that are over-dominated by $S$. The cardinality--redundance number of a graph $G$, which we denote by $CR(G)$, is the minimum among all cardinality--redundances $CR(S)$ taken over all dominating sets $S$. In this paper, we study those graphs whose cardinality--redundance decreases by two upon the removal of any arbitrary edge. We refer to such graphs as cardinality--redundance strong edge critical graphs. We give a general characterization for all cardinality--redundance strong edge critical graphs, and then focus on the cardinality--redundance strong edge critical graphs having cardinality--redundance $2$, and present several characterizations for these graphs.