We consider the problem of coloring edges of a graph subject to the following constraints: for every vertex v, all the edges incident with v have to be colored with at most q colors. The goal is to find a coloring satisfying the above constraints and using the maximum number of colors. Notice that the notion of coloring is different than in the classical edge coloring problem, as neighboring ed...

For two graphs, G and H , an edge coloring of a complete graph is (G,H)-good if there is no monochromatic subgraph isomorphic to G and no rainbow subgraph isomorphic to H in this coloring. The set of numbers of colors used by (G,H)-good colorings of Kn is called a mixed Ramsey spectrum. This note addresses a fundamental question of whether the spectrum is an interval. It is shown that the answe...

We produce an edge-coloring of the complete 3-uniform hypergraph on n vertices with e √ log logn) colors such that the edges spanned by every set of five vertices receive at least three distinct colors. This answers the first open case of a question of Conlon-Fox-Lee-Sudakov [1] who asked whether such a coloring exists with (log n) colors.

Given an edge colouring of a graph with a set of m colours, we say that the graph is (exactly) m-coloured if each of the colours is used. In 1999, Stacey and Weidl, partially resolving a conjecture of Erickson from 1994, showed that for a fixed natural number m > 2 and for all sufficiently large k, there is a k-colouring of the complete graph on N such that no complete infinite subgraph is exac...

The Ramsey number R(G1; G2; : : : ; Gn) is the smallest integer p such that for any n-edge coloring (E1; E2; : : : ; En) of Kp; Kp[Ei] contains Gi for some i, Gi as a subgraph in Kp[Ei]. Let R(m1; m2; : : : ; mn):=R(Km1 ; Km2 ; : : : ; Kmn); R(m; n):=R(m1; m2; : : : ; mn) if mi=m for i=1; 2; : : : ; n. A formula is obtained for R(G1; G2; : : : ; Gn). c © 2001 Elsevier Science B.V. All rights re...

We explore properties of edge colorings of graphs defined by set intersections. An edge coloring of a graphG with vertex set V ={1,2, . . . ,n} is called transitive if one can associate sets F1,F2, . . . ,Fn to vertices of G so that for any two edges ij,kl∈E(G), the color of ij and kl is the same if and only if Fi∩Fj =Fk∩Fl. The term transitive refers to a natural partial order on the color set...

The topic of this paper is the rectangle-free coloring of grids using four colors which is equivalent to the edge coloring of complete bipartite graphs without complete monochromatic subgraphs K2,2. Despite a strong mathematical background it is not known whether rectangle-free 4-colorable grids exist for five large grid sizes. We present in this paper an approach that solves the most complex p...

Let s(n, t) be the maximum number of colors in an edge-coloring of the complete graph Kn that has no rainbow spanning subgraph with diameter at most t. We prove s(n, t) = (n−2 2 ) +1 for n, t ≥ 3, while s(n, 2) = (n−2 2 )