Nullity of b-Bridge Coalescence Graphs
Khidir R. Sharaf, Nechirvan Badal Ibrahim · Journal of Zankoy Sulaimani - Part A · 2016
The nullity η(G) (degree of singularity) of a graph G is the algebraic multiplicity of thenumber zero in the spectrum of G. If G is a graph containing a vertex of degree one andH be the subgraph obtained from G, by deleting this vertex together with the vertexadjacent to it then, η(G) = η(H). In this paper, we proved that nullity of a graph is themaximum number of independent variables in a high zero-sum weighting for it. Theabove procedures are applied to evaluate the nullity of b-bridge coalescence graphs.They are also applied to determine the nullity of edge introducing between t-tuplecoalescence graphs and nullity of paths introducing between (n, m)-tuples of coalescencegraphs.