English

A user's guide to cloning systems

Group Theory 2022-03-24 v2

Abstract

In joint work of the author with Stefan Witzel, a procedure was developed for building new examples of groups in the extended family of R. Thompson's groups, using what we termed \emph{cloning systems}. These new Thompson-like groups can be thought of as limits of families of groups, though unlike other limiting processes, e.g., direct limits, these tend to be well behaved with respect to finiteness properties. In this expository note, we distill the crucial parts of that 50-page paper into a more digestible form, for those curious to understand the construction but less curious about the gritty details. We also give one new example, of a cloning system involving signed symmetric groups.

Keywords

Cite

@article{arxiv.1606.08762,
  title  = {A user's guide to cloning systems},
  author = {Matthew C. B. Zaremsky},
  journal= {arXiv preprint arXiv:1606.08762},
  year   = {2022}
}

Comments

v2: I never updated arXiv with the final version of this paper; here it is, 5 years later. In particular the first arXiv version didn't include Example 4.2 on ribbon braided Thompson groups, so now this is here. 14 pages, 5 figures. (Published in Topology Proceedings.) Short expository note summarizing the long paper arXiv:1405.5491

R2 v1 2026-06-22T14:37:02.138Z