English

Constraints for $b$-deformed constellations

Combinatorics 2023-12-19 v1

Abstract

Hurwitz numbers count branched covers of the sphere and have been of interest in various fields of mathematics. Motivated by the Matching-Jack conjecture of Goulden and Jackson, Chapuy and Do\l\k{e}ga recently introduced a notion of bb-deformed double weighted Hurwitz numbers. It equips orientable and non-orientable maps and constellations with bb-weights defined inductively. It is then unclear whether some elementary properties of orientable maps remain true due to the nature of the bb-weights. We consider here the case of the Virasoro constraints, which express that choosing a corner is equivalent to rooting in terms of generating functions. We prove this property for two families of bb-deformed Hurwitz numbers, namely 3-constellations and bipartite maps with black vertices of degrees bounded by 3. The proof is built upon functional equations from Chapuy and Do\l\k{e}ga and a lemma which extracts the constraints provided they close in some appropriate sense for the commutator. This requires to calculate the constraint algebra which in those two families do not form a Lie algebra but a generalization of independent interest with structure operators instead of structure constants.

Keywords

Cite

@article{arxiv.2312.10752,
  title  = {Constraints for $b$-deformed constellations},
  author = {Valentin Bonzom and Victor Nador},
  journal= {arXiv preprint arXiv:2312.10752},
  year   = {2023}
}

Comments

44 pages, 4 Figures. arXiv admin note: text overlap with arXiv:2312.00056

R2 v1 2026-06-28T13:53:58.699Z