English

The moment polytope of the abelian polygon space

Combinatorics 2021-08-17 v2 Algebraic Topology

Abstract

The moduli space of nn chains in the plane with generic side lengths that terminate on a fixed line is a smooth, closed manifold of dimension n1n-1. This manifold is also equipped with a locally standard action of Z2n1\mathbb{Z}_2^{n-1}. The orbit space of this action is a simple polytope called the moment polytope. Interestingly, this manifold is also the fixed point set of an involution on a toric manifold known as the abelian polygon space. In this article we show that the moment polytope of the moduli space of chains is completely characterized by the combinatorial data, called the \emph{short code} of the length vector. We also classify aspherical chain spaces using a result of Davis, Januszkiewicz and Scott.

Keywords

Cite

@article{arxiv.2106.13119,
  title  = {The moment polytope of the abelian polygon space},
  author = {Navnath Daundkar and Priyavrat Deshpande},
  journal= {arXiv preprint arXiv:2106.13119},
  year   = {2021}
}

Comments

20 pages, 6 figures. Version 2: misprints and typos fixed, Section 2 shortened, calculations of characteristic functions added. Final version, will appear in Topology and its Applications