English

Most big mapping class groups fail the Tits Alternative

Group Theory 2022-01-05 v1

Abstract

Let XX be a surface, possibly with boundary. Suppose it has infinite genus or infinitely many punctures, or a closed subset which is a disk with a Cantor set removed from its interior. For example, XX could be any surface of infinite type with only finitely many boundary components. We prove that the mapping class group of XX does not satisfy the Tits Alternative. That is, Map(X)(X) contains a finitely generated subgroup that is not virtually solvable and contains no nonabelian free group.

Keywords

Cite

@article{arxiv.2012.01310,
  title  = {Most big mapping class groups fail the Tits Alternative},
  author = {Daniel Allcock},
  journal= {arXiv preprint arXiv:2012.01310},
  year   = {2022}
}
R2 v1 2026-06-23T20:40:36.794Z