English

Algebraic homotopy classes of rational functions

Algebraic Topology 2009-12-23 v2 Algebraic Geometry

Abstract

We compute the set of naive pointed homotopy classes of endomorphisms of the projective line P^1 over the spectrum of a field. Our computation compares well with Fabien Morel's one of the motivic pointed homotopy classes of endomorphisms of P^1: there is an a priori monoid structure on the set of naive homotopy classes such that canonical map from this monoid to group of motivic homotopy classes is a group completion.

Keywords

Cite

@article{arxiv.0912.2227,
  title  = {Algebraic homotopy classes of rational functions},
  author = {Christophe Cazanave},
  journal= {arXiv preprint arXiv:0912.2227},
  year   = {2009}
}

Comments

30 pages; Improved the comparison between naive and motivic homotopy classes. Added one appendix

R2 v1 2026-06-21T14:22:40.206Z