Symmetric Dyck tilings, ballot tableaux and tree-like tableaux of shifted shapes

Abstract: Symmetric Dyck tilings and ballot tilings are certain tilings in the region surrounded by two ballot paths. We study the relations of combinatorial objects which are bijective to symmetric Dyck tilings such as labeled trees, Hermite histories, and perfect matchings. We also introduce two operations on labeled trees for symmetric Dyck tilings: symmetric Dyck tiling strip (symDTS) and symmetric Dyck tiling ribbon (symDTR). We give two definitions of Hermite histories for symmetric Dyck tilings, and show that they are equivalent by use of the correspondence between symDTS operation and an Hermite history. Since ballot tilings form a subset in the set of symmetric Dyck tilings, we construct an inclusive map from labeled trees for ballot tilings to labeled trees for symmetric Dyck tilings. By this inclusive map, the results for symmetric Dyck tilings can be applied to those of ballot tilings. We introduce and study the notions of ballot tableaux and tree-like tableaux of shifted shapes, which are generalizations of Dyck tableaux and tree-like tableaux, respectively. The correspondence between ballot tableaux and tree-like tableaux of shifted shapes is given by using the symDTR operation and the structure of labeled trees for symmetric Dyck tilings.