Infinitely many accumulation points of codegree Turán densities

2025/02/19 by Heng Li, Li, Heng, Weichan Liu +5
Mathematics · #05C35 #05C42 #05C65 #Combinatorics (math.CO) #FOS: Mathematics #Meromorphic and Entire Functions

paper · pdf · doi:10.48550/arxiv.2502.13485

openalex publication_date 2025/02/19 · openalex created_date 2025/02/21 · openalex updated_date 2026/07/28

Abstract

The codegree Turán density γ(F) of a k-graph F is the smallest γ∈[0,1) such that every k-graph H with δ_k-1(H)≥(γ+o(1))\vert V(H)\vert contains a copy of F. We prove that for all k,r∈ℕ with k≥3, (r-1)/(r) is an accumulation point of Γ^(k)=\γ(F):F is a k-graph\. This makes progress on a problem posed by Mubayi and Zhao.

Related

• Vanishing codegree Turán density implies vanishing uniform Turán density
• Codegree Turán density of complete r-uniform hypergraphs
• Hypergraphs accumulate infinitely often
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• Hypergraphs of arbitrary uniformity with vanishing codegree Turán density