English

Induced Tur\'an problems and traces of hypergraphs

Combinatorics 2020-02-19 v1

Abstract

Let FF be a graph. We say that a hypergraph HH contains an induced Berge FF if the vertices of FF can be embedded to HH (e.g., V(F)V(H)V(F)\subseteq V(H)) and there exists an injective mapping ff from the edges of FF to the hyperedges of HH such that f(xy)V(F)={x,y}f(xy) \cap V(F) = \{x,y\} holds for each edge xyxy of FF. In other words, HH contains FF as a trace. Let exr(n,BindF)ex_{r}(n,B_{ind} F) denote the maximum number of edges in an rr-uniform hypergraph with no induced Berge FF. Let ex(n,Kr,F)ex(n,K_r, F) denote the maximum number of KrK_r's in an FF-free graph on nn vertices. We show that these two Tur\'an type functions are strongly related.

Keywords

Cite

@article{arxiv.2002.07350,
  title  = {Induced Tur\'an problems and traces of hypergraphs},
  author = {Zoltan Furedi and Ruth Luo},
  journal= {arXiv preprint arXiv:2002.07350},
  year   = {2020}
}
R2 v1 2026-06-23T13:44:50.047Z