English

Induced rational exponents near two

Combinatorics 2026-05-06 v2

Abstract

Given a bipartite graph HH and a natural number ss, let ex(n,H,s)\mathrm{ex}^*(n,H,s) denote the maximum number of edges in an nn-vertex graph that contains neither Ks,sK_{s,s} nor an induced copy of HH. Hunter, Milojevi\'c, Sudakov, and Tomon conjectured that ex(n,H,s)=OH,s(ex(n,H))\mathrm{ex}^*(n,H,s)=O_{H,s}(\mathrm{ex}(n,H)) whenever HH is connected. Motivated by this conjecture and the rational exponents conjecture, Dong, Gao, Li, and Liu conjectured that for every rational r(1,2)r\in (1,2) there is a bipartite graph HH and an s0s_0 such that ex(n,H,s)=Θ(nr)\mathrm{ex}^*(n,H,s)=\Theta(n^r) for all ss0s\geq s_0. We prove that the latter conjecture holds for all rationals r=2a/br=2-a/b, where a,bNa,b\in\mathbb{N} satisfy bmax{a,(a1)2}b\geq \max\{a,(a-1)^2\}. Our result extends a well-known result of Conlon and Janzer to the induced setting and adds more evidence to support the former conjecture.

Keywords

Cite

@article{arxiv.2604.05288,
  title  = {Induced rational exponents near two},
  author = {Tao Jiang and Sean Longbrake},
  journal= {arXiv preprint arXiv:2604.05288},
  year   = {2026}
}

Comments

18 pages

R2 v1 2026-07-01T11:56:23.888Z