Now showing items 1-3 of 3

  • An interlacing approach for bounding the sum of Laplacian eigenvalues of graphs 

    Abiad, Aida; Fiol Mora, Miquel Àngel; Haemers, Willem H.; Perarnau Llobet, Guillem (2014)
    Conference report
    Open Access
    We apply eigenvalue interlacing techniques for obtaining lower and upper bounds for the sums of Laplacian eigenvalues of graphs, and characterize equality. This leads to generalizations of, and variations on theorems by ...
  • On the k-independence number of graphs 

    Abiad, Aida; Coutinho, Gabriel; Fiol Mora, Miquel Àngel (2019)
    Restricted access - publisher's policy
    This paper generalizes and unifies the existing spectral bounds on the k-independence number of a graph, which is the maximum size of a set of vertices at pairwise distance greater than k. The previous bounds known in the ...
  • Some spectral and quasi-spectral characterizations of distance-regular graphs 

    Abiad, Aida; Van Dam, Edwin R; Fiol Mora, Miquel Àngel (2016-10-01)
    Open Access
    In this paper we consider the concept of preintersection numbers of a graph. These numbers are determined by the spectrum of the adjacency matrix of the graph, and generalize the intersection numbers of a distance-regular ...