English

Mapping class group orbits of curves with self-intersections

Geometric Topology 2016-05-24 v2 Combinatorics Differential Geometry

Abstract

We study mapping class group orbits of homotopy and isotopy classes of curves with self-intersections. We exhibit the asymptotics of the number of such orbits of curves with a bounded number of self-intersections, as the complexity of the surface tends to infinity. We also consider the minimal genus of a subsurface that contains the curve. We determine the asymptotic number of orbits of curves with a fixed minimal genus and a bounded self-intersection number, as the complexity of the surface tends to infinity. As a corollary of our methods, we obtain that most curves that are homotopic are also isotopic. Furthermore, using a theorem by Basmajian, we get a bound on the number of mapping class group orbits on a given a hyperbolic surface that can contain short curves. For a fixed length, this bound is polynomial in the signature of the surface. The arguments we use are based on counting embeddings of ribbon graphs.

Keywords

Cite

@article{arxiv.1603.00846,
  title  = {Mapping class group orbits of curves with self-intersections},
  author = {Patricia Cahn and Federica Fanoni and Bram Petri},
  journal= {arXiv preprint arXiv:1603.00846},
  year   = {2016}
}

Comments

16 pages, 1 figure, generalized main result

R2 v1 2026-06-22T13:02:30.112Z