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Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

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Source. Z. Füredi and D. Gerbner, Hypergraphs without exponents, J. Combin. Theory Ser. A 184 (2021), Paper No. 105517, doi:10.1016/j.jcta.2021.105517. Labels and pages are those of the arXiv preprint arXiv:1906.06657v1 named on the source card.

Statement

Conjecture (p. 2, quoted). "We conjecture that examples with no exponents should exist for k=3k=3 and 4, too."

An example here is a single kk-uniform hypergraph HH for which there is no real α\alpha with exk(n,H)=Θ(nα)\mathrm{ex}_k(n,H)=\Theta(n^\alpha) (p. 2). The abstract (p. 1) states the same conjecture for k∈{3,4}k\in\{3,4\}. For k≥5k\ge5 such hypergraphs are given by Theorem 3.3, for instance Qk(3)Q_k(3). The paper recalls (p. 2) that the Ruzsa--Szemerédi (6,3)(6,3)-theorem gives a family of two 3-uniform hypergraphs with no exponent, so the open case is that of a single forbidden hypergraph.

Proof pointer

Posed without proof.

Read depth

Claims checked: read on the page images of pp. 1--2 of the preprint.

Bears on

  • Problem 713: the conjecture concerns 3- and 4-uniform hypergraphs, not graphs, and the paper relates it to the problem in no way beyond recalling the Erdős--Simonovits conjectures on graph exponents (pp. 1--2).