{ "id": "math/9712257", "version": "v1", "published": "1997-12-17T16:09:52.000Z", "updated": "1997-12-17T16:09:52.000Z", "title": "Fiber polytopes for the projections between cyclic polytopes", "authors": [ "C. A. Athanasiadis", "J. A. De Loera", "V. Reiner", "F. Santos" ], "comment": "28 pages with 1 postscript figure", "journal": "European J. Combin. 21:1 (2000), 19-47", "doi": "10.1006/eujc.1999.0319", "categories": [ "math.CO" ], "abstract": "The cyclic polytope $C(n,d)$ is the convex hull of any $n$ points on the moment curve ${(t,t^2,...,t^d):t \\in \\reals}$ in $\\reals^d$. For $d' >d$, we consider the fiber polytope (in the sense of Billera and Sturmfels) associated to the natural projection of cyclic polytopes $\\pi: C(n,d') \\to C(n,d)$ which \"forgets\" the last $d'-d$ coordinates. It is known that this fiber polytope has face lattice indexed by the coherent polytopal subdivisions of $C(n,d)$ which are induced by the map $\\pi$. Our main result characterizes the triples $(n,d,d')$ for which the fiber polytope is canonical in either of the following two senses: - all polytopal subdivisions induced by $\\pi$ are coherent, - the structure of the fiber polytope does not depend upon the choice of points on the moment curve. We also discuss a new instance with a positive answer to the Generalized Baues Problem, namely that of a projection $\\pi:P\\to Q$ where $Q$ has only regular subdivisions and $P$ has two more vertices than its dimension.", "revisions": [ { "version": "v1", "updated": "1997-12-17T16:09:52.000Z" } ], "analyses": { "subjects": [ "52B05", "52B12", "52B35" ], "keywords": [ "fiber polytope", "cyclic polytope", "moment curve", "coherent polytopal subdivisions", "main result characterizes" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1997math.....12257A" } } }