A trinity of duality: Non-separable planar maps, β(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 Preville-Ratelle and the present author. Another example is the class of β ( 1 , 0 ) -trees, which has a mysterious involution h proposed by Claesson, Kitaev and Steingrimsson (2009). These two classes of combinatorial objects are all in bijection with the class of non-separable planar maps, which is closed under map duality. In this article, we show that we can identify the notions of duality in these three classes using previously known natural bijections, which leads to a bijective proof of a result from Kitaev and de Mier (2013).