Results 31 to 40 of about 322,612 (279)

DISTANCE-REGULAR GRAPH WITH INTERSECTION ARRAY {27, 20, 7; 1, 4, 21} DOES NOT EXIST

open access: yesUral Mathematical Journal, 2020
In the class of distance-regular graphs of diameter 3 there are 5 intersection arrays of graphs with at most 28 vertices and noninteger eigenvalue. These arrays are \(\{18,14,5;1,2,14\}\), \(\{18,15,9;1,1,10\}\), \(\{21,16,10;1,2,12\}\), \(\{24,21,3;1,3 ...
Konstantin S. Efimov   +1 more
doaj   +1 more source

THE VERTEX DISTANCE COMPLEMENT SPECTRUM OF SUBDIVISION VERTEX JOIN AND SUBDIVISION EDGE JOIN OF TWO REGULAR GRAPHS

open access: yesUral Mathematical Journal, 2021
The vertex distance complement (VDC) matrix \(\textit{C}\), of a connected graph  \(G\) with vertex set consisting of \(n\) vertices, is a real symmetric matrix \([c_{ij}]\) that takes the value \(n - d_{ij}\) where \(d_{ij}\) is the distance between the
Ann Susa Thomas   +2 more
doaj   +1 more source

Edge-distance-regular graphs are distance-regular

open access: yesJournal of Combinatorial Theory, Series A, 2013
A graph is edge-distance-regular when it is distance-regular around each of its edges and it has the same intersection numbers for any edge taken as a root. In this paper we give some (combinatorial and algebraic) proofs of the fact that every edge-distance-regular graph $\G$ is distance-regular and homogeneous.
Cámara Vallejo, Marc   +4 more
openaire   +5 more sources

Distance-regular Cayley graphs with small valency

open access: yes, 2019
We consider the problem of which distance-regular graphs with small valency are Cayley graphs. We determine the distance-regular Cayley graphs with valency at most $4$, the Cayley graphs among the distance-regular graphs with known putative intersection ...
Jazaeri, Mojtaba, van Dam, Edwin R.
core   +1 more source

Handicap Labelings of 4-Regular Graphs

open access: yesAdvances in Electrical and Electronic Engineering, 2017
Let G be a simple graph, let f : V(G)→{1,2,...,|V(G)|} be a bijective mapping. The weight of v ∈ V(G) is the sum of labels of all vertices adjacent to v. We say that f is a distance magic labeling of G if the weight of every vertex is the same
Petr Kovar   +3 more
doaj   +1 more source

Distance-regular Subgraphs in a Distance-regular Graph, IV

open access: yesEuropean Journal of Combinatorics, 1995
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +4 more sources

The spectral excess theorem for distance-regular graphs having distance-d graph with fewer distinct eigenvalues [PDF]

open access: yes, 2015
Let G be a distance-regular graph with diameter d and Kneser graph K=Gd, the distance-d graph of G. We say that G is partially antipodal when K has fewer distinct eigenvalues than G. In particular, this is the case of antipodal distance-regular graphs (K
Fiol Mora, Miquel Àngel
core   +3 more sources

The matching polynomial of a distance-regular graph

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2000
A distance-regular graph of diameter d has 2d intersection numbers that determine many properties of graph (e.g., its spectrum). We show that the first six coefficients of the matching polynomial of a distance-regular graph can also be determined from ...
Robert A. Beezer, E. J. Farrell
doaj   +1 more source

Distance spectrum of Indu–Bala product of graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2016
The D-eigenvalues μ1,μ2,…,μn of a graph G of order n are the eigenvalues of its distance matrix D and form the distance spectrum or D-spectrum of G denoted by SpecD(G). Let G1 and G2 be two regular graphs. The Indu–Bala product of G1 and G2 is denoted by
G. Indulal, R. Balakrishnan
doaj   +1 more source

Entanglement of free Fermions on Hadamard graphs

open access: yesNuclear Physics B, 2020
Free Fermions on vertices of distance-regular graphs are considered. Bipartitions are defined by taking as one part all vertices at a given distance from a reference vertex.
Nicolas Crampé, Krystal Guo, Luc Vinet
doaj   +1 more source

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