Distance-regular graphs

ER Van Dam, JH Koolen, H Tanaka - arXiv preprint arXiv:1410.6294, 2014 - arxiv.org
This is a survey of distance-regular graphs. We present an introduction to distance-regular
graphs for the reader who is unfamiliar with the subject, and then give an overview of some …

[HTML][HTML] Optimization of eigenvalue bounds for the independence and chromatic number of graph powers

A Abiad, G Coutinho, MÀ Fiol, BD Nogueira… - Discrete …, 2022 - Elsevier
The k th power of a graph G=(V, E), G k, is the graph whose vertex set is V and in which two
distinct vertices are adjacent if and only if their distance in G is at most k. This article proves …

[HTML][HTML] A new class of polynomials from the spectrum of a graph, and its application to bound the k-independence number

MA Fiol - Linear Algebra and its Applications, 2020 - Elsevier
The k-independence number of a graph is the maximum size of a set of vertices at pairwise
distance greater than k. A graph is called k-partially walk-regular if the number of closed …

[HTML][HTML] Resistance characterizations of equiarboreal graphs

J Zhou, L Sun, C Bu - Discrete Mathematics, 2017 - Elsevier
A weighted (unweighted) graph G is called equiarboreal if the sum of weights (the number)
of spanning trees containing a given edge in G is independent of the choice of edge. In this …

The 2-partially distance-regular graphs such that their second largest local eigenvalues are at most one

Y Zhang, X Liang, JH Koolen - Discrete Mathematics, 2022 - Elsevier
In this paper, we will classify the 2-partially distance-regular graphs whose each local graph
has second largest eigenvalue at most one. As an application, we classify the 2-walk-regular …

On bipartite distance-regular Cayley graphs with small diameter

ER van Dam, M Jazaeri - arXiv preprint arXiv:2109.13849, 2021 - arxiv.org
We study bipartite distance-regular Cayley graphs with diameter three or four. We give
sufficient conditions under which a bipartite Cayley graph can be constructed on the …

Spectrally extremal vertices, strong cospectrality and state transfer

G Coutinho - arXiv preprint arXiv:1501.04398, 2015 - arxiv.org
In order to obtain perfect state transfer between two sites in a network of interacting qubits,
their corresponding vertices in the underlying graph must satisfy a combinatorial property …

[HTML][HTML] Some spectral and quasi-spectral characterizations of distance-regular graphs

A Abiad, ER Van Dam, MA Fiol - Journal of Combinatorial Theory, Series A, 2016 - Elsevier
In this paper we consider the concept of preintersection numbers of a graph. These numbers
are determined by the spectrum of the adjacency matrix of the graph, and generalize the …

Edge-disjoint spanning trees and forests of graphs

J Zhou, C Bu, HJ Lai - Discrete Applied Mathematics, 2021 - Elsevier
The spanning tree packing number of a graph G is the maximum number of edge-disjoint
spanning trees in G, and the arboricity of G is the minimum number of edge-disjoint forests …

Thin Q-Polynomial Distance-Regular Graphs Have Bounded

YY Tan, JH Koolen, MY Cao, J Park - Graphs and Combinatorics, 2022 - Springer
In this paper, we look at distance-regular graphs with induced subgraphs K r, t, where 1≤
r≤ t are integers. In particular, we show that if a distance-regular graph Γ with diameter D≥ …