Graph homomorphisms and chromatic numbers are foundational concepts in modern graph theory, with widespread applications that extend from combinatorial optimisation to theoretical computer science. A ...

A k-graph is an ordered couple (V, E) where V is a set and E a set of k-tuples of elements of V; thus, a 2-graph is an ordinary graph. If the notions of the independent set and the chromatic number ...

For a given set M of positive integers, a well-known problem of Motzkin asked to determine the maximal asymptotic density of M-sets, denoted by μ(M), where an M-set is a set of non-negative integers ...