Expansion in matrix-weighted graphs

Autor: Jakob Hansen
Rok vydání: 2021
Předmět:
Zdroj: Linear Algebra and its Applications. 630:252-273
ISSN: 0024-3795
DOI: 10.1016/j.laa.2021.08.009
Popis: A matrix-weighted graph is an undirected graph with a $k\times k$ positive semidefinite matrix assigned to each edge. There are natural generalizations of the Laplacian and adjacency matrices for such graphs. These matrices can be used to define and control expansion for matrix-weighted graphs. In particular, an analogue of the expander mixing lemma and one half of a Cheeger-type inequality hold for matrix-weighted graphs. A new definition of a matrix-weighted expander graph suggests the tantalizing possibility of families of matrix-weighted graphs with better-than-Ramanujan expansion.
21 pages, 2 figures
Databáze: OpenAIRE