English

A verification of Wilf's conjecture up to genus 100

Group Theory 2023-10-13 v1

Abstract

For a numerical semigroup SNS \subseteq \mathbb{N}, let m,e,c,gm,e,c,g denote its multiplicity, embedding dimension, conductor and genus, respectively. Wilf's conjecture (1978) states that e(cg)ce(c-g) \ge c. As of 2023, Wilf's conjecture has been verified by computer up to genus g66g \le 66. In this paper, we extend the verification of Wilf's conjecture up to genus g100g \le 100. This is achieved by combining three main ingredients: (1) a theorem in 2020 settling Wilf's conjecture in the case em/3e \ge m/3, (2) an efficient trimming of the tree T\mathcal{T} of numerical groups identifying and cutting out irrelevant subtrees, and (3) the implementation of a fast parallelized algorithm to construct the tree T\mathcal{T} up to a given genus. We further push the verification of Wilf's conjecture up to genus 120120 in the particular case where mm divides cc. Finally, we unlock three previously unknown values of the number ngn_g of numerical semigroups of genus gg, namely for g=73,74,75g=73,74,75.

Keywords

Cite

@article{arxiv.2310.07742,
  title  = {A verification of Wilf's conjecture up to genus 100},
  author = {Manuel Delgado and Shalom Eliahou and Jean Fromentin},
  journal= {arXiv preprint arXiv:2310.07742},
  year   = {2023}
}