English

Perfect tilings with the generalised triangle in $k$-graphs

Combinatorics 2025-08-19 v1

Abstract

Denote by TkT_k the generalised triangle, a kk-uniform hypergraph on vertex set {1,2,,2k1}\{1,2,\dots,2k-1\} with three edges {1,,k1,k}\{1,\dots,k-1,k\},{1,,k1,k+1}\{1,\dots,k-1,k+1\} and {k,k+1,,2k1}\{k,k+1,\dots,2k-1\}. Recently, Bowtell, Kathapurkar, Morrison and Mycroft [arXiv: 2505.05606] established the exact minimum codegree threshold for perfect T3T_3-tilings in 33-graphs. In this paper, we extend their result to all k3k \geq 3, determining the optimal minimum codegree threshold for perfect TkT_k-tilings in kk-graphs. Our proof uses the lattice-based absorption method, as is usual, but develops a unified and effective approach to build transferrals for all uniformities, which is of independent interest. Additionally, we establish an asymptotically tight minimum codegree threshold for a rainbow variant of the problem.

Keywords

Cite

@article{arxiv.2508.12311,
  title  = {Perfect tilings with the generalised triangle in $k$-graphs},
  author = {Weichan Liu and Xiangxiang Nie and Donglei Yang and Lin-Peng Zhang},
  journal= {arXiv preprint arXiv:2508.12311},
  year   = {2025}
}
R2 v1 2026-07-01T04:53:38.009Z