Exploració per autor "Gago Álvarez, Silvia"Més informació

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    • On decay centrality in graphs 

      Coronicová Hurajová, Jana; Gago Álvarez, Silvia; Madaras, Tomas (2018-08-06)
      Article
      Accés obert
      The decay centrality of a vertex v in a graph G with respect to a parameter d¿(0,1) is a polynomial in d such that for fixed k the coefficient of dk is equal to the number of vertices of G at distance k from v. This invariant ...

    • On golden spectral graphs 

      Estrada Roger, Ernesto; Gago Álvarez, Silvia (2009-03-26)
      Report de recerca
      Accés obert
      The concept of golden spectral graphs is introduced and some of their general properties reported. Golden spectral graphs are those having a golden proportion for the spectral ratios defined on the basis of the spectral ...

    • The betweenness centrality of a graph 

      Gago Álvarez, Silvia (2007-05-10)
      Article
      Accés obert
      A measure of the centrality of a vertex of a graph is the portion of shortest paths crossing through it between other vertices of the graph. This is called betweenness centrality and here we study some of its general ...

    • The group inverse of extended symmetric and periodic Jacobi matrices 

      Gago Álvarez, Silvia (2016-02-02)
      Report de recerca
      Accés obert
      In this work, we explicitly compute the group inverse of symmetric and periodic Jacobi matrices with constant elements that have been extended by adding a row and a column conveniently de ned. For this purpose, we interpret ...

    • The inverses of some circulant matrices 

      Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gago Álvarez, Silvia; Jiménez Jiménez, María José; Mitjana Riera, Margarida (2015-11-01)
      Article
      Accés obert
      We present here necessary and su cient conditions for the invertibility of circulant and symmetric matrices that depend on three parameters and moreover, we explicitly compute the inverse. The techniques we use are related ...

    • Two-side boundary value problems in distance-regular graphs 

      Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gago Álvarez, Silvia (Universidad de Almería, 2012)
      Comunicació de congrés
      Accés obert
      In this work we analyze regular boundary value problems on a distanceregular graph associated with Schr¨odinger operators in the case that the boundary has two vertices. Moreover, we obtain the Green matrix for each ...