2012/01/10 by Mühle, Henri
#05E99 (Secondary) #06A07 (Primary) #Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1201.2020
The m-Tamari lattices Tn(m) were recently introduced by Bergeron and Préville-Ratelle as posets on m-Dyck paths, and it was shown by Bousquet-Mélou, Fusy and Préville-Ratelle that these lattices form intervals in the classical Tamari lattice Tnm. It follows from a theorem by Björner and Wachs and a basic property of EL-shellable posets, that the m-Tamari lattices are EL-shellable. In this article, we define a new EL-labeling of the m-Tamari lattices completely in terms of m-Dyck paths. With the help of this labeling, we compute the values of the Möbius function of Tn(m), and we characterize the intervals of Tn(m) according to their topological properties.