English

New skew Laplacian energy of a simple digraph

Combinatorics 2013-04-25 v1

Abstract

For a simple digraph GG of order nn with vertex set {v1,v2,,vn}\{v_1,v_2,\ldots, v_n\}, let di+d_i^+ and did_i^- denote the out-degree and in-degree of a vertex viv_i in GG, respectively. Let D+(G)=diag(d1+,d2+,,dn+)D^+(G)=diag(d_1^+,d_2^+,\ldots,d_n^+) and D(G)=diag(d1,d2,,dn)D^-(G)=diag(d_1^-,d_2^-,\ldots,d_n^-). In this paper we introduce SL~(G)=D~(G)S(G)\widetilde{SL}(G)=\widetilde{D}(G)-S(G) to be a new kind of skew Laplacian matrix of GG, where D~(G)=D+(G)D(G)\widetilde{D}(G)=D^+(G)-D^-(G) and S(G)S(G) is the skew-adjacency matrix of GG, and from which we define the skew Laplacian energy SLE(G)SLE(G) of GG as the sum of the norms of all the eigenvalues of SL~(G)\widetilde{SL}(G). Some lower and upper bounds of the new skew Laplacian energy are derived and the digraphs attaining these bounds are also determined.

Keywords

Cite

@article{arxiv.1304.6465,
  title  = {New skew Laplacian energy of a simple digraph},
  author = {Qingqiong Cai and Xueliang Li and Jiangli Song},
  journal= {arXiv preprint arXiv:1304.6465},
  year   = {2013}
}

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13 pages