Positive $m$-divisible non-crossing partitions and their Kreweras maps
Abstract
We study positive -divisible non-crossing partitions and their positive Kreweras maps. In classical types, we describe their combinatorial realisations as certain non-crossing set partitions. We also realise these positive Kreweras maps as pseudo-rotations on a circle, respectively on an annulus. We enumerate positive -divisible non-crossing partitions in classical types that are invariant under powers of the positive Kreweras maps with respect to several parameters. In order to cope with the exceptional types, we develop a different combinatorial model in general type describing positive -divisible non-crossing partitions that are invariant under powers of the positive Kreweras maps. We finally show that altogether these results establish several cyclic sieving phenomena.
Keywords
Cite
@article{arxiv.2506.14996,
title = {Positive $m$-divisible non-crossing partitions and their Kreweras maps},
author = {Christian Krattenthaler and Christian Stump},
journal= {arXiv preprint arXiv:2506.14996},
year = {2025}
}
Comments
AmS-LaTeX, 169 pages