EJC
2006
13 years 4 months ago
2006
The general symplectic graph Sp(2, q) is introduced. It is shown that Sp(2, q) is strongly regular. Its parameters are computed, its chromatic number and group of graph automorphis...
EJC
2006
13 years 4 months ago
2006
As a generalization of Deza graphs, we introduce Deza digraphs and describe the basic theory of these graphs. We also prove the necessary and sufficient conditions when a weakly d...
EJC
2006
13 years 4 months ago
2006
It is known that a graded lattice of rank n is supersolvable if and only if it has an EL-labelling where the labels along any maximal chain are exactly the numbers 1, 2, . . . , n ...
EJC
2006
13 years 4 months ago
2006
EJC
2006
13 years 4 months ago
2006
A class C of graphs is said to be H-bounded if each graph in the class C admits a homomorphism to H. We give a general necessary and sufficient condition for the existence of boun...
EJC
2006
13 years 4 months ago
2006
EJC
2006
13 years 4 months ago
2006
EJC
2006
13 years 4 months ago
2006
A general method for finding elementary abelian regular covering projections of finite connected graphs is applied to the Petersen graph. As a result, a complete list of pairwise ...
EJC
2006
13 years 4 months ago
2006
We apply Computational Algebra methods to the construction of Hadamard matrices with two circulant cores, given by Fletcher, Gysin and Seberry. We introduce the concept of Hadamar...
EJC
2006
13 years 4 months ago
2006
Average distance of a graph is expressed in terms of its canonical metric representation. The equality can be modified to an inequality in such a way that it characterizes isometr...