A counterexample to sparse removal
Combinatorics
2013-12-12 v1
Abstract
The Tur\'{a}n number of a graph , denoted , is the maximum number of edges in an -vertex graph with no subgraph isomorphic to . Solymosi conjectured that if is any graph and where , then any -vertex graph with the property that each edge lies in exactly one copy of has edges. This can be viewed as conjecturing a possible extension of the removal lemma to sparse graphs, and is well-known to be true when is a non-bipartite graph, in particular when is a triangle, due to Ruzsa and Szemer\'{e}di. Using Sidon sets we exhibit infinitely many bipartite graphs for which the conjecture is false.
Cite
@article{arxiv.1312.2994,
title = {A counterexample to sparse removal},
author = {Craig Timmons and Jacques Verstraete},
journal= {arXiv preprint arXiv:1312.2994},
year = {2013}
}