English

Alon-Tarsi for hypergraphs

Combinatorics 2025-01-03 v1 Discrete Mathematics

Abstract

Given a hypergraph H=(V,E)H=(V,E), define for every edge eEe\in E a linear expression with arguments corresponding with the vertices. Next, let the polynomial pHp_H be the product of such linear expressions for all edges. Our main goal was to find a relationship between the Alon-Tarsi number of pHp_H and the edge density of HH. We prove that AT(pH)=ed(H)+1AT(p_H)=\lceil ed(H)\rceil+1 if all the coefficients in pHp_H are equal to 11. Our main result is that, no matter what those coefficients are, they can be permuted within the edges so that for the resulting polynomial pHp_H^\prime, AT(pH)2ed(H)+1AT(p_H^\prime)\leq 2\lceil ed(H)\rceil+1 holds. We conjecture that, in fact, permuting the coefficients is not necessary. If this were true, then in particular a significant generalization of the famous 1-2-3 Conjecture would follow.

Keywords

Cite

@article{arxiv.2501.00157,
  title  = {Alon-Tarsi for hypergraphs},
  author = {Marcin Anholcer and Bartłomiej Bosek and Grzegorz Gutowski and Michał Lasoń and Jakub Przybyło and Oriol Serra and Michał Tuczyński and Lluís Vena and Mariusz Zając},
  journal= {arXiv preprint arXiv:2501.00157},
  year   = {2025}
}
R2 v1 2026-06-28T20:52:54.743Z