English

Simple formulas for constellations and bipartite maps with prescribed degrees

Combinatorics 2020-12-11 v2

Abstract

We obtain simple quadratic recurrence formulas counting bipartite maps on surfaces with prescribed degrees (in particular, 2k2k-angulations), and constellations. These formulas are the fastest known way of computing these numbers. Our work is a natural extension of previous works on integrable hierarchies (2-Toda and KP), namely the Pandharipande recursion for Hurwitz numbers (proven by Okounkov and simplified by Dubrovin-Yang-Zagier), as well as formulas for several models of maps (Goulden-Jackson, Carrell-Chapuy, Kazarian-Zograf). As for those formulas, a bijective interpretation is still to be found. We also include a formula for monotone simple Hurwitz numbers derived in the same fashion. These formulas also play a key role in subsequent work of the author with T. Budzinski establishing the hyperbolic local limit of random bipartite maps of large genus.

Keywords

Cite

@article{arxiv.1904.05371,
  title  = {Simple formulas for constellations and bipartite maps with prescribed degrees},
  author = {Baptiste Louf},
  journal= {arXiv preprint arXiv:1904.05371},
  year   = {2020}
}

Comments

16 pages, 4 figures, extended abstract in FPSAC 2019, to appear in CJM

R2 v1 2026-06-23T08:35:53.437Z