English

A nonstandard take on central sets

Combinatorics 2018-12-21 v1 Logic

Abstract

We present the basic theory of central subsets of semigroups from the nonstandard perspective. A key feature of this perspective is the replacement of the algebra of ultrafilters with the algebra of elements of iterated hyperextensions, a technique first employed by Mauro Di Nasso.

Keywords

Cite

@article{arxiv.1812.08362,
  title  = {A nonstandard take on central sets},
  author = {Isaac Goldbring},
  journal= {arXiv preprint arXiv:1812.08362},
  year   = {2018}
}

Comments

28 pages. First draft. Comments very welcome!

R2 v1 2026-06-23T06:50:42.471Z