A note on Laplacian eigenvalues and domination
نویسندگان
چکیده
منابع مشابه
Note on the normalized Laplacian eigenvalues of signed graphs
The normalized Laplacian of a graph was introduced by F.R.K. Chung and has been studied extensively over the last decade. In this paper, we introduce the notion of the normalized Laplacian of signed graphs and extend some fundamental concepts of the normalized Laplacian from graphs to signed graphs.
متن کاملOn Laplacian Eigenvalues of a Graph
Let G be a connected graph with n vertices and m edges. The Laplacian eigenvalues are denoted by μ1(G) ≥ μ2(G) ≥ ·· · ≥ μn−1(G) > μn(G) = 0. The Laplacian eigenvalues have important applications in theoretical chemistry. We present upper bounds for μ1(G)+ · · ·+μk(G) and lower bounds for μn−1(G)+ · · ·+μn−k(G) in terms of n and m, where 1 ≤ k ≤ n−2, and characterize the extremal cases. We also ...
متن کاملA note on domination and independence-domination numbers of graphs∗
Vizing’s conjecture is true for graphs G satisfying γ(G) = γ(G), where γ(G) is the domination number of a graph G and γ(G) is the independence-domination number of G, that is, the maximum, over all independent sets I in G, of the minimum number of vertices needed to dominate I . The equality γ(G) = γ(G) is known to hold for all chordal graphs and for chordless cycles of length 0 (mod 3). We pro...
متن کاملA note on domination and total domination in prisms
Recently, Azarija et al. considered the prism G K2 of a graph G and showed that γt(G K2) = 2γ(G) if G is bipartite, where γt(G) and γ(G) are the total domination number and the domination number of G. In this note, we give a simple proof and observe that there are similar results for other pairs of parameters. We also answer a question from that paper and show that for all graphs γt(G K2) ≥ 4 3...
متن کاملEla a Note on a Distance Bound Using Eigenvalues of the Normalized Laplacian Matrix∗
Let G be a connected graph, and let X and Y be subsets of its vertex set. A previously published bound is considered that relates the distance between X and Y to the eigenvalues of the normalized Laplacian matrix for G, the volumes of X and Y , and the volumes of their complements. A counterexample is given to the bound, and then a corrected version of the bound is provided.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Linear Algebra and its Applications
سال: 2014
ISSN: 0024-3795
DOI: 10.1016/j.laa.2014.02.025