English

The linear Tur\'an number of the 3-graph $P_5$

Combinatorics 2026-01-28 v1

Abstract

We prove that for any linear 3-graph on nn vertices without a path of length 5, the number of edges is at most 1511n\frac{15}{11}n, and the equality holds if and only if the graph is the disjoint union of G0G_0, a graph with 11 vertices and 15 edges. Thus, exL(n,P5)1511nex_L(n,P_5)\leq \frac{15}{11}n, and the equality holds if and only if 11n11|n.

Keywords

Cite

@article{arxiv.2601.19068,
  title  = {The linear Tur\'an number of the 3-graph $P_5$},
  author = {Chaoliang Tang and Hehui Wu and Junchi Zhang},
  journal= {arXiv preprint arXiv:2601.19068},
  year   = {2026}
}