摘要:Let be an undirected simple graph of order . Let be the adjacency matrix of , and let be its eigenvalues. The energy of is defined as . Denote by a bipartite graph. In this paper, we establish the sufficient conditions for having a Hamiltonian path or cycle or to be Hamilton-connected in terms of the energy of the complement of , and give the sufficient condition for having a Hamiltonian cycle in terms of the energy of the quasi-complement of .