Graphs and Hermitian matrices: exact interlacing
Combinatorics
2007-05-23 v2 Commutative Algebra
Abstract
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.
Cite
@article{arxiv.math/0609572,
title = {Graphs and Hermitian matrices: exact interlacing},
author = {Bela Bollobas and Vladimir Nikiforov},
journal= {arXiv preprint arXiv:math/0609572},
year = {2007}
}