{ "id": "2110.07257", "version": "v3", "published": "2021-10-14T11:08:23.000Z", "updated": "2023-11-07T19:09:31.000Z", "title": "$P$-associahedra", "authors": [ "Pavel Galashin" ], "comment": "30 pages, 10 figures; v2: minor bibliography updates; v3: updated title and terminology. Final version to appear in Selecta Mathematica", "categories": [ "math.CO", "math.GT" ], "abstract": "For each poset $P$, we construct a polytope $A(P)$ called the $P$-associahedron. Similarly to the case of graph associahedra, the faces of $A(P)$ correspond to certain nested collections of subsets of $P$. The Stasheff associahedron is a compactification of the configuration space of $n$ points on a line, and we recover $A(P)$ as an analogous compactification of the space of order-preserving maps $P\\to\\mathbb{R}$. Motivated by the study of totally nonnegative critical varieties in the Grassmannian, we introduce affine poset cyclohedra and realize these polytopes as compactifications of configuration spaces of $n$ points on a circle. For particular choices of (affine) posets, we obtain associahedra, cyclohedra, permutohedra, and type B permutohedra as special cases.", "revisions": [ { "version": "v3", "updated": "2023-11-07T19:09:31.000Z" } ], "analyses": { "subjects": [ "52B11", "05E99", "06A07", "54D35" ], "keywords": [ "configuration space", "affine poset cyclohedra", "compactification", "graph associahedra", "stasheff associahedron" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }