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In this paper, in terms of Wiener index, hyper-Wiener index and Harary index, we first give some sufficient conditions for a nearly balance bipartite graph with given minimum degree to be traceable. Secondly, we establish some conditions for a k-connected graph to be Hamilton-connected and traceable for every vertex, respectively.

In this paper, we establish sufficient conditions for a connected claw-free graph to be traceable in terms of the signless Laplacian spectral radius of the graph or Laplacian eigenvalues of its complements, respectively.

Let S n c be the set of all connected graph each of which is a complement of an n -vertex unicyclic graph. Li and Wang (2012) determined the graphs with the least signless Laplacian eignvalue among all the graphs of the complements of n -vertex trees. In this paper, as a continuance of it, the unique graph among S n c which minimizes the least signless Laplacian eigenvalue is identified.

Let G be a simple graph and let Q (G) be the signless Laplacian matrix of G. In this paper we obtain some results on the spectral perturbation of the matrix Q (G) under an edge addition or an edge contraction.

In this paper, we study the Hamiltonicity of graphs with large minimum degree. Firstly, we present some conditions for a simple graph to be Hamilton-connected and traceable from every vertex in terms of the spectral radius of the graph or its complement respectively. Secondly, we give the conditions for a nearly balanced bipartite graph to be traceable in terms of spectral radius, signless Laplacian spectral radius of the graph or its quasi-complement respectively., Comment: 21 pages, 2 figures. arXiv admin note: text overlap with arXiv:1602.01033 by other authors

In this paper we establish some spectral conditions for a graph to be Hamilton-connected in terms of the spectral radius of the adjacency matrix or the signless Laplacian of the graph or its complement. For the existence of Hamiltonian paths or cycles in a graph, we also give a sufficient condition by the signless Laplacian spectral radius.