English

An upper bound on the LS-category in presence of the fundamental group

Algebraic Topology 2019-12-25 v2

Abstract

We prove that \catX\cd(π1(X))+dimX2 \cat X\le \frac{\cd(\pi_1(X))+\dim X}{2} for every CW complex XX where \cd(π1(X))\cd(\pi_1(X)) denotes the cohomological dimension of the fundamental group of XX. We obtain this as a corollary of the inequality \catX\cat(uX)+dimX2 \cat X\le\frac{\cat (u_X)+\dim X}{2} where uX:XBπ1(X)u_X:X\to B\pi_1(X) is a classifying map for the universal covering of XX.

Keywords

Cite

@article{arxiv.1806.04475,
  title  = {An upper bound on the LS-category in presence of the fundamental group},
  author = {Alexander Dranishnikov},
  journal= {arXiv preprint arXiv:1806.04475},
  year   = {2019}
}