A trinity of duality: non-separable planar maps, $\beta$-(1,0) trees and synchronized intervals

Abstract

The dual of a map is a fundamental construction on combinatorial maps, but many other combinatorial objects also possess their notion of duality. For instance, the Tamari lattice is isomorphic to its order dual, which induces an involution on the set of so-called "synchronized intervals" introduced by Pr\'eville-Ratelle and the present author. Another example is the class of $\beta$-(1,0) trees, which has a mysterious involution $h$ proposed by Claesson, Kitaev and Steingr\'imsson (2009). These two classes of combinatorial objects are all in bijection with the class of non-separable planar maps, which is closed by map duality. In this article, we show that we can identify the notions of duality in these three classes of objects using previously known natural bijections, which leads to a bijective proof of a result from Kitaev and de Mier (2013). We also discuss how various statistics are transferred by duality and by the bijections we used.