Noncrossing partitions of a marked surface
arXiv:2212.13799 · doi:10.1137/23M1627675
Abstract
We define noncrossing partitions of a marked surface without punctures (interior marked points). We show that the natural partial order on noncrossing partitions is a graded lattice and describe its rank function topologically. Lower intervals in the lattice are isomorphic to products of noncrossing partition lattices of other surfaces. We similarly define noncrossing partitions of a symmetric marked surface with double points and prove some of the analogous results. The combination of symmetry and double points plays a role that one might have expected to be played by punctures.
arXiv comment39 pages, 13 figures. Version 3: Removed the assertion that the noncrossing partitions of a symmetric marked surface with double points form a lattice and provided a counterexample. Version 4: Minor changes, additions, and corrections in connection with the release of arXiv:2312.17331. Version 5: accepted SIAM J. Discrete Math. Version 6: final pre-publication version