English

Polynomial removal lemmas for ordered graphs

Combinatorics 2023-03-13 v2

Abstract

A recent result of Alon, Ben-Eliezer and Fischer establishes an induced removal lemma for ordered graphs. That is, if FF is an ordered graph and ε>0\varepsilon>0, then there exists δF(ε)>0\delta_{F}(\varepsilon)>0 such that every nn-vertex ordered graph GG containing at most δF(ε)nv(F)\delta_{F}(\varepsilon) n^{v(F)} induced copies of FF can be made induced FF-free by adding/deleting at most εn2\varepsilon n^2 edges. We prove that δF(ε)\delta_{F}(\varepsilon) can be chosen to be a polynomial function of ε\varepsilon if and only if V(F)=2|V(F)|=2, or FF is the ordered graph with vertices x<y<zx<y<z and edges {x,y},{x,z}\{x,y\},\{x,z\} (up to complementation and reversing the vertex order). We also discuss similar problems in the non-induced case.

Keywords

Cite

@article{arxiv.2110.03577,
  title  = {Polynomial removal lemmas for ordered graphs},
  author = {Lior Gishboliner and István Tomon},
  journal= {arXiv preprint arXiv:2110.03577},
  year   = {2023}
}
R2 v1 2026-06-24T06:42:45.440Z