Ludwin A. BASILIO-HERNÁNDEZ, Walter CARBALLOSA, Jesús LEAÑOS, José M. SIGARRETA
We introduce the differential polynomial of a graph. The differential polynomial of a graph G of order n is the polynomial B(G; x):=Σk=-n∂(G) Bk(G) xn+k, where Bk(G) denotes the number of vertex subsets of G with differential equal to k. We state some properties of B(G; x) and its coefficients. In particular, we compute the differential polynomial for complete, empty, path, cycle, wheel and double star graphs. We also establish some relationships between B(G; x) and the differential polynomials of graphs which result by removing, adding, and subdividing an edge from G.