1,378 research outputs found
The number of independent sets of tricyclic graphs
AbstractLet Tn be the class of tricyclic graphs G on n vertices. In this work, the graphs in Tn with the smallest number of independent sets are characterized
Trees with Given Stability Number and Minimum Number of Stable Sets
We study the structure of trees minimizing their number of stable sets for
given order and stability number . Our main result is that the
edges of a non-trivial extremal tree can be partitioned into stars,
each of size or , so that every vertex is included in at most two
distinct stars, and the centers of these stars form a stable set of the tree.Comment: v2: Referees' comments incorporate
A characterization of graphs with rank 5
AbstractThe rank of a graph G is defined to be the rank of its adjacency matrix. In this paper, we consider the following problem: what is the structure of a connected graph G with rank 5? or equivalently, what is the structure of a connected n-vertex graph G whose adjacency matrix has nullity n-5? In this paper, we completely characterize connected graphs G whose adjacency matrix has rank 5
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