English

$B$-rigidity of ideal almost Pogorelov polytopes

Algebraic Topology 2020-12-29 v4 Combinatorics

Abstract

Toric topology assigns to each nn-dimensional combinatorial simple convex polytope PP with mm facets an (m+n)(m+n)-dimensional moment-angle manifold ZP\mathcal{Z}_P with an action of a compact torus TmT^m such that ZP/Tm\mathcal{Z}_P/T^m is a convex polytope of combinatorial type PP. A simple nn-polytope is called BB-rigid, if any isomorphism of graded rings H(ZP,Z)=H(ZQ,Z)H^*(\mathcal{Z}_P,\mathbb Z)= H^*(\mathcal{Z}_Q,\mathbb Z) for a simple nn-polytope QQ implies that PP and QQ are combinatorially equivalent. An ideal almost Pogorelov polytope is a combinatorial 33-polytope obtained by cutting off all the ideal vertices of an ideal right-angled polytope in the Lobachevsky (hyperbolic) space L3\mathbb L^3. These polytopes are exactly the polytopes obtained from any, not necessarily simple, convex 33-polytopes by cutting off all the vertices followed by cutting off all the "old" edges. The boundary of the dual polytope is the barycentric subdivision of the boundary of the old polytope (and also of its dual polytope). We prove that any ideal almost Pogorelov polytope is BB-rigid. This produces three cohomologically rigid families of manifolds over ideal almost Pogorelov manifolds: moment-angle manifolds, canonical 66-dimensional quasitoric manifolds and canonical 33-dimensional small covers, which are "pullbacks from the linear model".

Keywords

Cite

@article{arxiv.2005.07665,
  title  = {$B$-rigidity of ideal almost Pogorelov polytopes},
  author = {Nikolai Erokhovets},
  journal= {arXiv preprint arXiv:2005.07665},
  year   = {2020}
}

Comments

18 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:2004.04873. In version 2 small inaccuracies in the geometrical part are corrected. In version 3 some references were added and some misprints were corrected. In version 4 the funding information was added

R2 v1 2026-06-23T15:34:42.223Z