English

Decomposition of Greedy Tamari Intervals and Bipartite Planar Maps

Combinatorics 2026-07-01 v1

Abstract

The greedy Tamari poset, inspired by the well-studied Tamari lattice, was recently defined by Dermenjian in the more general setting of greedy ν\nu-Tamari posets. Bousquet-M\'elou and Chapoton counted intervals of the greedy mm-Tamari poset in 2024 by solving a functional equation, and found that they are equi-enumerous to planar (m+1)(m+1)-constellations. In this work, we give a combinatorial proof of this fact for the case m=1m = 1, which also gives the refined enumeration conjectured by Bousquet-M\'elou and Chapoton. This is done by establishing a recursive decomposition of greedy Tamari intervals isomorphic to that of bipartite planar maps. We also propose a more general and refined conjecture for the case of general mm.

Keywords

Cite

@article{arxiv.2607.01206,
  title  = {Decomposition of Greedy Tamari Intervals and Bipartite Planar Maps},
  author = {Philippe Biane and Wenjie Fang},
  journal= {arXiv preprint arXiv:2607.01206},
  year   = {2026}
}

Comments

22 pages, 14 figures, comments are welcome