Now showing items 1-6 of 6

    • A note on the order of iterated line digraphs 

      Dalfó, Cristina; Fiol, Miguel Angel (Wiley Periodicals Inc., 2016-06)
      Given a digraph G, we propose a new method to find therecurrence equation for the number of vertices nk of the k-iterated linedigraph Lk(G), for k≥0, where L0(G)=G. We obtain this result by usingthe minimal polynomial of ...
    • 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, ...
    • Cospectral digraphs from locally line digraphs 

      Dalfó, Cristina; Fiol, Miguel Angel (Elsevier, 2016-07)
      A digraph Γ =(V, E) is a line digraph when every pair of vertices u, v∈V have either equal or disjoint in-neighborhoods. When this condition only applies for vertices in a given subset (with at least two elements), we say ...
    • On d-Fibonacci digraphs 

      Dalfó, Cristina; Fiol, Miguel Angel (Institut Teknologi Bandung (ITB) Indonesia; Indonesian Combinatorial Society (InaCombS); GTA Research Group, University of Newcastle (Australia), 2021)
      The d-Fibonacci digraphs F(d, k), introduced here, have the number of vertices following some generalized Fibonacci-like sequences. They can be defined both as digraphs on alphabets and as iterated line digraphs. Here we ...
    • 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 ...
    • The spectra of subKautz and cyclic Kautz digraphs 

      Dalfó, Cristina (Elsevier, 2017)
      Kautz digraphs K(d, `) are a well-known family of dense digraphs, widely studied as a good model for interconnection networks. Closely related with these, the cyclic Kautz CK(d, `) and the subKautz sK(d, 2) digraphs were ...