O Pikhurko, K Staden, ZB Yilma - Mathematical proceedings of the …, 2017 - cambridge.org
Let k:=(k1,..., ks) be a sequence of natural numbers. For a graph G, let F (G; k) denote the number of colourings of the edges of G with colours 1,..., s such that, for every c∈{1,..., s}, the …
C Hoppen, H Lefmann, K Odermann - SIAM Journal on Discrete Mathematics, 2017 - SIAM
We consider a multicolored version of a question posed by Erdös and Rothschild. For a fixed positive integer r and a fixed graph F, we look for n-vertex graphs that admit the …
C Hoppen, H Lefmann, K Odermann - European Journal of Combinatorics, 2017 - Elsevier
Inspired by previous work of Balogh (2006), we show that, given r≥ 5 and n large, the balanced complete bipartite graph K n∕ 2, n∕ 2 is the n-vertex graph that admits the largest …
C Hoppen, H Lefmann - European Journal of Combinatorics, 2015 - Elsevier
We consider an extremal problem motivated by a question of Erdős and Rothschild (Erdős, 1974) regarding edge-colorings of graphs avoiding a given monochromatic subgraph. An …
C Hoppen, H Lefmann, D Nolibos - Discrete Mathematics, 2021 - Elsevier
Given integers r≥ 2, k≥ 3 and 2≤ s≤(k 2), and a graph G, we consider r-edge-colorings of G with no copy of a complete graph K k on k vertices where s or more colors appear, which …
JO Bastos, C Hoppen, H Lefmann, A Oertel… - Discrete Applied …, 2023 - Elsevier
We consider a version of the Erdős–Rothschild problem for families of graph patterns. For any fixed k≥ 3, let r 0 (k) be the largest integer such that the following holds for all 2≤ r≤ r 0 …
The typical extremal problem asks how large a structure can be without containing a forbidden substructure. The Erdős–Rothschild problem, introduced in 1974 by Erdős and …
C Hoppen, H Lefmann, K Odermann - Electronic Notes in Discrete …, 2015 - Elsevier
A rainbow Erdős-Rothschild problem Page 1 A rainbow Erdos-Rothschild problem Carlos Hoppena,1,2 Hanno Lefmannb,1,3 Knut Odermannb,1,4 a Instituto de Matemática …
O Pikhurko, K Staden - Forum of Mathematics, Sigma, 2023 - cambridge.org
Given a sequence of natural numbers and a graph G, let denote the number of colourings of the edges of G with colours, such that, for every, the edges of colour c contain no clique of …