A subdivision theorem for vertices not on internal paths

In 1975 Hoffman and Smith showed that for a graph G≠D˜n with an internal path, the value of the largest eigenvalue decreases strictly each time we subdivide the internal path. In this paper we extend this result to show that for a graph G≠K1,4 with a vertex of degree 4 or more, we can subdivide said vertex to create an internal path and the value of the largest eigenvalue also strictly decreases.