Search
Search Results
-
Weakly distance-regular digraphs whose underlying graphs are distance-regular, I
Weakly distance-regular digraphs are a natural directed version of distance-regular graphs. In Wang and Suzuki (Discrete Math 264:225–236, 2003), the...
-
On Bounding the Diameter of a Distance-Regular Graph
In this note we investigate how to use an initial portion of the intersection array of a distance-regular graph to give an upper bound for the...
-
Distance-regular Cayley graphs over dicyclic groups
The characterization of distance-regular Cayley graphs originates from the problem of identifying strongly regular Cayley graphs, or equivalently,...
-
PBIB-Designs from Certain Subsets of Distance-Regular Graphs
Partially balanced incomplete block (PBIB)-designs are well known to be the generalization of combinatorial 2-designs. In this paper, we first...
-
The k-adjacency operators and adjacency Jacobi matrix on distance-regular graphs
We deal in this work with a class of graphs, namely, the class of distance-regular graphs, in which on the basis of k -adjacency operators, the...
-
The Koolen–Park Boundary and Distance-Regular Graphs without m-Claws
AbstractJ.H. Koolen and J. Park found a boundary for the maximum size of the coclique in the neighborhood of a vertex of a distance-regular graph....
-
On the distance spectra of central vertex join and central edge join of two regular graphs
In this article, we compute the distance, distance Laplacian, and distance signless Laplacian eigenvalues of central vertex and central edge join of...
-
The Largest Moore Graph and a Distance-Regular Graph with Intersection Array {55, 54, 2; 1, 1, 54}
We point out possible automorphisms of a distance-regular graph Γ with intersection array {55, 54, 2; 1, 1, 54} and spectrum 55 1 , 7 1617 ,−1 110 ,−8 1408 .
-
Quadratic Embedding Constants of Graph Joins
The quadratic embedding constant (QE constant) of a graph is a new characteristic value of a graph defined through the distance matrix. We derive...
-
-
Weakly Distance-Regular Digraphs of One Type of Arcs
In this paper, we classify all commutative weakly distance-regular digraphs of girth g and one type of arcs under the assumption that
... -
Diameter of the Commutativity Graph of the Real Sedenions
The commutativity graph of the real sedenion algebra is considered. It is shown that the elements whose imaginary parts are not zero divisors...