منابع مشابه
Interlacing Eigenvalues and Graphs
We give several old and some new applications of eigenvalue interlacing to matrices associated to graphs. Bounds are obtained for characteristic numbers of graphs, such as the size of a maximal (colclique, the chromatic number, the diameter, and the bandwidth, in terms of the eigenvalues of the Standard adjacency matrix or the Laplacian matrix. We also deal with inequalities and regularity resu...
متن کاملInterlacing adjoints on directed graphs
For an integer k ≥ 1, the k-th interlacing adjoint of a digraph G is the digraph ιk(G) with vertex-set V (G) k , and arcs ((u1, . . . , uk), (v1, . . . , vk)) such that (ui, vi) ∈ A(G) for i = 1, . . . , k and (vi, ui+1) ∈ A(G) for i = 1, . . . , k − 1. For every k we derive upper and lower bounds for the chromatic number of ιk(G) in terms of that of G. In particular, we find tight bounds on th...
متن کاملHitting times and Interlacing Eigenvalues: a Stochastic Approach Using Intertwinings
We develop a systematic matrix-analytic approach, based on intertwinings of Markov semigroups, for proving theorems about hitting-time distributions for finite-state Markov chains—an approach that (sometimes) deepens understanding of the theorems by providing corresponding sample-path-by-sample-path stochastic constructions. We employ our approach to give new proofs and constructions for two th...
متن کاملGraphs and Hermitian matrices: Exact interlacing
We prove conditions for equality between the extreme eigenvalues of a matrix and its quotient: In particular, we give a lower bound on the largest singular value of a matrix and generalize a result of Finck and Grohmann about the largest eigenvalue of a graph. Keywords: extreme eigenvalues, tight interlacing, graph Laplacian, singular values, nonnegative matrix 1 Introduction Our notation is st...
متن کاملGraphs and Hermitian matrices: eigenvalue interlacing
Our first aim in this note is to prove some inequalities relating the eigenvalues of a Hermitian matrix with the eigenvalues of its principal matrices induced by a partition of the index set. One of these inequalities extends an inequality proved by Hoffman in [9]. Secondly, we apply our inequalities to estimate the eigenvalues of the adjacency matrix of a graph, and prove, in particular, that ...
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ژورنال
عنوان ژورنال: Linear Algebra and its Applications
سال: 1995
ISSN: 0024-3795
DOI: 10.1016/0024-3795(95)00199-2