Results 11 to 20 of about 322,612 (279)

On almost distance-regular graphs [PDF]

open access: yesJournal of Combinatorial Theory, Series A, 2011
Distance-regular graphs are a key concept in Algebraic Combinatorics and have given rise to several generalizations, such as association schemes. Motivated by spectral and other algebraic characterizations of distance-regular graphs, we study `almost distance-regular graphs'.
Dalfó Simó, Cristina   +4 more
openaire   +11 more sources

Shilla distance-regular graphs

open access: yesEuropean Journal of Combinatorics, 2010
14 ...
Koolen, JH, Park, J
openaire   +5 more sources

The distance spectrum of two new operations of graphs [PDF]

open access: yesTransactions on Combinatorics, 2020
Let $G$ be a connected graph with vertex set $V(G)=\{v_1, v_2,\ldots,v_n\}$‎. ‎The distance matrix $D=D(G)$ of $G$ is defined so that its $(i,j)$-entry is equal to the distance $d_G(v_i,v_j)$ between the vertices $v_i$ and $v_j$ of $G$‎. ‎The eigenvalues
Zikai Tang   +3 more
doaj   +1 more source

Arithmetic completely regular codes [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2016
In this paper, we explore completely regular codes in the Hamming graphs and related graphs. Experimental evidence suggests that many completely regular codes have the property that the eigenvalues of the code are in arithmetic progression.
Jacobus Koolen   +3 more
doaj   +1 more source

Some Resolving Parameters in a Class of Cayley Graphs

open access: yesJournal of Mathematics, 2022
Resolving parameters are a fundamental area of combinatorics with applications not only to many branches of combinatorics but also to other sciences.
Jia-Bao Liu, Ali Zafari
doaj   +1 more source

ON SOME VERTEX-TRANSITIVE DISTANCE-REGULAR ANTIPODAL COVERS OF COMPLETE GRAPHS

open access: yesUral Mathematical Journal, 2022
In the present paper, we classify abelian antipodal distance-regular graphs \(\Gamma\) of diameter 3 with the following property: \((*)\) \(\Gamma\) has a transitive group of automorphisms \(\widetilde{G}\) that induces a primitive almost simple ...
Ludmila Yu. Tsiovkina
doaj   +1 more source

The Generalized Distance Spectrum of the Join of Graphs [PDF]

open access: yes, 2020
Let G be a simple connected graph. In this paper, we study the spectral properties of the generalized distance matrix of graphs, the convex combination of the symmetric distance matrix D(G) and diagonal matrix of the vertex transmissions Tr(G) .
Alhevaz, Abdollah   +3 more
core   +2 more sources

D-magic strongly regular graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2020
For a set of distances D, a graph G on n vertices is said to be D-magic if there exists a bijection and a constant k such that for any vertex x, where is the D-neighbourhood set of x.
Rinovia Simanjuntak, Palton Anuwiksa
doaj   +1 more source

Geometric aspects of 2-walk-regular graphs [PDF]

open access: yes, 2013
A $t$-walk-regular graph is a graph for which the number of walks of given length between two vertices depends only on the distance between these two vertices, as long as this distance is at most $t$. Such graphs generalize distance-regular graphs and $t$
Cámara, Marc   +3 more
core   +1 more source

SHILLA GRAPHS WITH \(b=5\) AND \(b=6\)

open access: yesUral Mathematical Journal, 2021
A \(Q\)-polynomial Shilla graph with \(b = 5\) has intersection arrays \(\{105t,4(21t+1),16(t+1); 1,4 (t+1),84t\}\), \(t\in\{3,4,19\}\). The paper proves that distance-regular graphs with these intersection arrays do not exist.
Alexander A. Makhnev, Ivan N. Belousov
doaj   +1 more source

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