English

A nice acyclic matching on the nerve of the partition lattice

Algebraic Topology 2020-09-29 v4

Abstract

The author has already proven that the space Δ(Πn)/G\Delta(\Pi_n)/G is homotopy equivalent to a wedge of spheres of dimension n3n-3 for all natural numbers n3n\geq 3 and all subgroups GS1×Sn1G\subset S_1\times S_{n-1}. We construct an S1×Sn1S_1\times S_{n-1}-equivariant acyclic matching on Δ(Πn)\Delta(\Pi_n) together with a description of its critical simplices. This is also a more elementary approach to determining the number of spheres. We also develop new methods for Equivariant Discrete Morse Theory by adapting the Patchwork Theorem and poset maps with small fibers from Discrete Morse Theory.

Keywords

Cite

@article{arxiv.1204.2693,
  title  = {A nice acyclic matching on the nerve of the partition lattice},
  author = {Ralf Donau},
  journal= {arXiv preprint arXiv:1204.2693},
  year   = {2020}
}

Comments

9 pages, 3 figures, final correction