English

Hypergraph removal with polynomial bounds

Combinatorics 2025-06-04 v2

Abstract

Given a fixed kk-uniform hypergraph FF, the FF-removal lemma states that every hypergraph with few copies of FF can be made FF-free by the removal of few edges. Unfortunately, for general FF, the constants involved are given by incredibly fast-growing Ackermann-type functions. It is thus natural to ask for which FF one can prove removal lemmas with polynomial bounds. One trivial case where such bounds can be obtained is when FF is kk-partite. Alon proved that when k=2k=2 (i.e. when dealing with graphs), only bipartite graphs have a polynomial removal lemma. Kohayakawa, Nagle and R\"odl conjectured in 2002 that Alon's result can be extended to all k>2k>2, namely, that the only kk-graphs FF for which the hypergraph removal lemma has polynomial bounds are the trivial cases when FF is kk-partite. In this paper we prove this conjecture.

Keywords

Cite

@article{arxiv.2202.07567,
  title  = {Hypergraph removal with polynomial bounds},
  author = {Lior Gishboliner and Asaf Shapira},
  journal= {arXiv preprint arXiv:2202.07567},
  year   = {2025}
}
R2 v1 2026-06-24T09:39:00.686Z