Now showing items 1-5 of 5

    • An algebraic approach to lifts of digraphs 

      Dalfó, Cristina; Fiol, Miguel Angel; Miller, Mirka; Ryan, Joe; Sirán, Jozef (Elsevier, 2018)
      We present some applications of a new matrix approach for studying the properties of the lift of a voltage digraph, which has arcs weighted by the elements of a group. As a main result, when the involved group is Abelian, ...
    • On the spectra and eigenspaces of the universal adjacency matrices of arbitrary lifts of graphs 

      Dalfó, Cristina; Fiol, Miguel Angel; Pavlíková, Sona; Sirán, Jozef (Taylor & Francis, 2022-02-19)
      The universal adjacency matrix U of a graph Γ, with adjacency matrix A, is a linear combination of A, the diagonal matrix D of vertex degrees, the identity matrix I, and the all-1 matrix J with real coefficients, that is, ...
    • Spectra and eigenspaces of arbitrary lifts of graphs 

      Dalfó, Cristina; Fiol, Miguel Angel; Pavlíiková, Sona; Sirán, Jozef (Springer, 2021-09-23)
      We describe, in a very explicit way, a method for determining the spectra and bases of all the corresponding eigenspaces of arbitrary lifts of graphs (regular or not).
    • Spectra and eigenspaces of arbitrary lifts of graphs 

      Dalfó, Cristina; Fiol, Miguel Angel; Pavlíková, Sona; Sirán, Jozef (Faculty of Mathematics, Physics and Informatics, Comenius University, 2019)
      We describe, in a very explicit way, a method for determining the spec-tra and bases of all the corresponding eigenspaces of arbitrary lifts of graphs (regularor not).
    • The spectra of lifted digraphs 

      Dalfó, Cristina; Fiol, Miguel Angel; Sirán, Jozef (Springer, 2019-01-02)
      We present a method to derive the complete spectrum of the lift Γα of a base digraph Γ , with voltage assignment α on a (finite) group G. The method is based on assigning to Γ a quotient-like matrix whose entries are ...