English

Comparing list-color functions of uniform hypergraphs with their chromatic polynomials (III)

Combinatorics 2024-10-02 v4

Abstract

For a hypergraph H{\cal H}, let P(H,k)P({\cal H},k) and Pl(H,k)P_l({\cal H},k) be its chromatic polynomial and list-color function respectively, and let τ(H)\tau'({\cal H}) be the least non-negative integer qq such that P(H,k)=Pl(H,k)P({\cal H},k)=P_l({\cal H},k) holds for all integers kqk\ge q. In this article, we show that for any rr-uniform hypergraph H{\cal H} of order nn and size mm and any kk-assignment LL of H{\cal H}, where r3r\ge 3, P(H,L)P(H,k)min{0.02k,k(m1)}knr1eE(H)(kveL(v))P({\cal H},L)-P({\cal H},k)\ge \min \{0.02k, k-(m-1)\} k^{n-r-1}\sum_{e\in E({\cal H})} \left ( k-\left |\bigcap_{v\in e}L(v)\right | \right ) holds for km14k\ge m-1\ge 4. It follows that τ(H)m1\tau'({\cal H})\le m-1, improving the current best result on τ(H)\tau'({\cal H}).

Keywords

Cite

@article{arxiv.2212.02045,
  title  = {Comparing list-color functions of uniform hypergraphs with their chromatic polynomials (III)},
  author = {Fengming Dong and Meiqiao Zhang},
  journal= {arXiv preprint arXiv:2212.02045},
  year   = {2024}
}

Comments

This article is a sister paper of "Compare list-color functions of uniform hypergraphs with their chromatic polynomials (I)" at arXiv:2305.02497. The later is now completed in a new approach, and it covers the main result in the former