Counting Cycles
(a) Find a relation between the Katz centrality defined in Eq. (8.3) and the
α-centrality introduced in Section 2.3.
(b) Prove that C3 is k-cyclic for every k ≥ 3 except k = 4.
(c) Prove that the property ck(Ck) = 2k is valid for every k ≥ 3. See in the text the
proof that c3(C3) = 6.
(d) Consider a graph G with N nodes K links and adjacency matrix A = {aij}. Prove
that the number of subgraphs of G isomorphic to graphs H1, H2, H3, H4 and H5,
shown in Figures 8.1, 8.2 and 8.3, are respectively: