EJC
2008
13 years 4 months ago
2008
We explore the connection between locally constrained graph homomorphisms and degree matrices arising from an equitable partition of a graph. We provide several equivalent charact...
EJC
2008
13 years 4 months ago
2008
In this paper, the q
EJC
2008
13 years 4 months ago
2008
In this paper, we compute the congruences of Catalan and Motzkin numbers modulo 4 and 8. in particular, we prove the conjecture proposed by Deutsch and Sagan that no Motzkin numbe...
EJC
2008
13 years 4 months ago
2008
Two new series of substitution tilings are introduced in which the tiles appear in infinitely many orientations. It is shown that several properties of the well-known pinwheel tili...
EJC
2008
13 years 4 months ago
2008
The adaptable chromatic number of a graph G is the smallest integer k such that for any edge k-colouring of G there exists a vertex kcolouring of G in which the same colour never ...
EJC
2008
13 years 4 months ago
2008
This paper revisits the existence and construction problems for polygonal designs (a special class of partially balanced incomplete block designs associated with regular polygons)...
EJC
2008
13 years 4 months ago
2008
The numbers game is a one-player game played on a finite simple graph with certain "amplitudes" assigned to its edges and with an initial assignment of real numbers to i...
EJC
2008
13 years 4 months ago
2008
We study restricted homomorphism dualities in the context of classes with bounded expansion. This presents a generalization of restricted dualities obtained earlier for bounded deg...
EJC
2008
13 years 4 months ago
2008
Tension-continuous (shortly TT) mappings are mappings between the edge sets of graphs. They generalize graph homomorphisms. From another perspective, tension-continuous mappings a...
EJC
2008
13 years 4 months ago
2008
The notion of noncrossing linked partition arose from the study of certain transforms in free probability theory. It is known that the number of noncrossing linked partitions of [...