English

Iteration of functions and contractibility of acyclic 2-complexes

Group Theory 2020-03-23 v3 Geometric Topology

Abstract

We show that there can be no algorithm to decide whether infinite recursively described acyclic aspherical 2-complexes are contractible. We construct such a complex that is contractible if and only if the Collatz conjecture holds.

Keywords

Cite

@article{arxiv.1910.00931,
  title  = {Iteration of functions and contractibility of acyclic 2-complexes},
  author = {Ian J Leary},
  journal= {arXiv preprint arXiv:1910.00931},
  year   = {2020}
}

Comments

Third version: more minor misprints removed