An application of Hoffman graphs for spectral characterizations of graphs

Qianqian Yang; Aida Abiad Monge; Jack H. Koolen

doi:10.37236/6428

An application of Hoffman graphs for spectral characterizations of graphs

Qianqian Yang
, Aida Abiad Monge
, Jack H. Koolen^*

^*Corresponding author for this work

QE Operations research

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

In this paper, we present that the 2-clique extension of the (t+1) × (t+1)-grid is determined by its spectrum if t is large enough. By applying results of Gavrilyuk and Koolen, this implies that the Grassmann graph J ₂(2D, D) is determined by its intersection array as a distance-regular graph if D is large enough. The main tool we are using is Hoffman graphs.

Original language	English
Article number	P1.12
Number of pages	24
Journal	Electronic Journal of Combinatorics
Volume	24
Issue number	1
DOIs	https://doi.org/10.37236/6428
Publication status	Published - 20 Jan 2017

Keywords

Hoffman graph
graph eigenvalue
interlacing
walk-regular
spectral characterizations
SMALLEST EIGENVALUE

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10.37236/6428Licence: CC BY

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keywords = "Hoffman graph, graph eigenvalue, interlacing, walk-regular, spectral characterizations, SMALLEST EIGENVALUE",

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KW - graph eigenvalue

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KW - spectral characterizations

KW - SMALLEST EIGENVALUE

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An application of Hoffman graphs for spectral characterizations of graphs

Abstract

Keywords

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