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PreprintCC BY 4.0arXiv

A Tight Fractional Version of Generalized Tuza's Conjecture

Abstract

For an r-uniform hypergraph H, let ν(H) be the maximum number of edges no two of which share r−1 vertices, and τ(H) the minimum number of (r−1)-sets such that every edge contains one of them. Aharoni and Zerbib conjectured that τ(H)≤⌈(r+1)/2⌉ ν(H), which for r=3 generalizes Tuza's conjecture on triangles. We prove that the fractional relaxation τ*(H) of τ(H) satisfies τ*(H)≤(r+1)/2 ν(H). This constant is best possible for every r, and for r≥4 it improves on the previous bound of roughly 3r/4.

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BibTeX
@misc{wang2026tight,
  title = {{A Tight Fractional Version of Generalized Tuza's Conjecture}},
  author = {Sichen Wang},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.35836},
  eprint = {2609.35836},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.35836},
  note = {CC BY 4.0},
}
RIS
TY  - UNPB
TI  - A Tight Fractional Version of Generalized Tuza's Conjecture
AU  - Sichen Wang
PY  - 2026
DA  - 2026/09/24
PB  - arXiv
DO  - 10.48550/arxiv.2609.35836
UR  - https://arxiv.org/abs/2609.35836
AB  - For an r-uniform hypergraph H, let ν(H) be the maximum number of edges no two of which share r−1 vertices, and τ(H) the minimum number of (r−1)-sets such that every edge contains one of them. Aharoni and Zerbib conjectured that τ(H)≤⌈(r+1)/2⌉ ν(H), which for r=3 generalizes Tuza's conjecture on triangles. We prove that the fractional relaxation τ^*(H) of τ(H) satisfies τ^*(H)≤(r+1)/2 ν(H). This constant is best possible for every r, and for r≥4 it improves on the previous bound of roughly 3r/4.
ER  -