English

Minimal triangulations of circle bundles

Algebraic Topology 2024-08-16 v2 Combinatorics

Abstract

A triangulation of a circle bundle EπB E \xrightarrow[\text{}]{\pi} B is a triangulation of the total space EE and the base BB such that the projection π\pi is a simplicial map. In the paper we address the following questions: Which circle bundles can be triangulated over a given triangulation of the base? What are the minimal triangulations of a bundle? A complete solution for semisimplicial triangulations was given by N. Mn\"{e}v. Our results deal with classical triangulations, that is, simplicial complexes. We give an exact answer for an infinite family of triangulated spheres (including the boundary of the 33-simplex, the boundary of the octahedron, the suspension over an nn-gon, the icosahedron). For the general case we present a sufficient criterion for existence of a triangulation. Some minimality results follow straightforwadly.

Keywords

Cite

@article{arxiv.2311.04214,
  title  = {Minimal triangulations of circle bundles},
  author = {Gaiane Panina and Maksim Turevskii},
  journal= {arXiv preprint arXiv:2311.04214},
  year   = {2024}
}