A Lower Bound on Spectral Radius of Graphs with Given Domination Number 2

The domination number γ(G) of a graph G(V,E) is the minimum cardinality of a subset S of V such that every vertex is either in the set S or is adjacent to some vertices in the set.In this paper we study a lower bound on spectral radius of graphs on n vertices with domination number 2,and determine the extremal graphs that attain the lower bound on spectral radius.