TY - JOUR
T1 - Some upper bounds for the signless laplacian spectral radius of digraphs
AU - Xi, Weige
AU - Wang, Ligong
N1 - Publisher Copyright:
© 2020 University of Isfahan.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Let G = (V(G), E(G) be a digraph without loops and multiarcs, where V(G) = (v1, v2,..., vn) and E(G) are the vertex set and the arc set of G, respectively. Let be the outdegree of the vertex vi. Let A(G) be the adjacency matrix of G and D(G) = diag be the diagonal matrix with outdegrees of the vertices of G. Then we call Q(G) = D(G) +-4(G) the signless Laplacian matrix of G. The spectral radius of Q(G) is called the signless Laplacian spectral radius of G. denoted by q(G). In this paper, some upper bounds for q(G) are obtained. Furthermore, some upper bounds on q(G) involving outdegrees and the average 2-outdegrees of the vertices of G are also derived.
AB - Let G = (V(G), E(G) be a digraph without loops and multiarcs, where V(G) = (v1, v2,..., vn) and E(G) are the vertex set and the arc set of G, respectively. Let be the outdegree of the vertex vi. Let A(G) be the adjacency matrix of G and D(G) = diag be the diagonal matrix with outdegrees of the vertices of G. Then we call Q(G) = D(G) +-4(G) the signless Laplacian matrix of G. The spectral radius of Q(G) is called the signless Laplacian spectral radius of G. denoted by q(G). In this paper, some upper bounds for q(G) are obtained. Furthermore, some upper bounds on q(G) involving outdegrees and the average 2-outdegrees of the vertices of G are also derived.
KW - Digraph
KW - Signless laplacian spectral radius
KW - Upper bounds
UR - http://www.scopus.com/inward/record.url?scp=85081688381&partnerID=8YFLogxK
U2 - 10.22108/toc.2019.105894.1515
DO - 10.22108/toc.2019.105894.1515
M3 - 文章
AN - SCOPUS:85081688381
SN - 2251-8657
VL - 8
SP - 49
EP - 60
JO - Transactions on Combinatorics
JF - Transactions on Combinatorics
IS - 4
ER -