On the nullity of the line graph of unicyclic graph with depth one

Abstract: A connected graph with a unique cycle is called a unicyclic graph. A unicyclic graph with depth one may be thought of as being obtained from a cycle by appending pendent edges on each vertex in the cycle (for some integer ), denoted by . In this paper, we give a complete characterization on the nullity of the line graph as follows: Let . Then [(i)] if and only if and . [(ii)] if and only if and either [(1)] for , the length of any zero chain of is even and ; or [(2)] and one of and must hold. [(iii)] , otherwise. [Copyright &y& Elsevier]