$B$-rigidity of the property to be an almost Pogorelov polytope
Abstract
Toric topology assigns to each -dimensional combinatorial simple convex polytope with facets an -dimensional moment-angle manifold with an action of a compact torus such that is a convex polytope of combinatorial type . We study the notion of -rigidity. A property of a polytope is called -rigid, if any isomorphism of graded rings for a simple -polytope implies that it also has this property. We study families of -dimensional polytopes defined by their cyclic -edge-connectivity. These families include flag polytopes and Pogorelov polytopes, that is polytopes realizable as bounded right-angled polytopes in Lobachevsky space . Pogorelov polytopes include fullerenes -- simple polytopes with only pentagonal and hexagonal faces. It is known that the properties to be flag and Pogorelov polytope are -rigid. We focus on almost Pogorelov polytopes, which are strongly cyclically -edge-connected polytopes. They correspond to right-angled polytopes of finite volume in . There is a subfamily of ideal almost Pogorelov polytopes corresponding to ideal right-angled polytopes. We prove that the properties to be an almost Pogorelov polytope and an ideal almost Pogorelov polytope are -rigid. As a corollary we obtain that -dimensional associahedron and permutohedron are -rigid. We generalize methods known for Pogorelov polytopes. We obtain results on -rigidity of subsets in and prove an analog of the so-called separable circuit condition (SCC). As an example we consider the ring .
Keywords
Cite
@article{arxiv.2004.04873,
title = {$B$-rigidity of the property to be an almost Pogorelov polytope},
author = {Nikolai Erokhovets},
journal= {arXiv preprint arXiv:2004.04873},
year = {2020}
}
Comments
42 pages, 19 figures. In version 3 the results on $B$-rigid subsets are improved. As a corollary we obtain that any ideal almost Pogorelov polytope is $B$-rigid. In version 4 small inaccuracies in the abstract and in the introduction were corrected. In version 5 some references were added and some misprints were corrected