Submission date: 15 March 2015.

Abstract:

We study ultraproducts of finite residue rings \prod{n in N} Z/nZ /U where U is a non-principal ultrafilter. We find sufficient conditions of the ultrafilter U to determine if the resulting ultraproduct \prod{n in N} Z/nZ /U has simple, NIP, NTP2 but not simple nor NIP, or TP2 theory, noting that all these four cases occur.

Mathematics Subject Classification: 03C45, 03C20

Keywords and phrases:

Full text arXiv 1503.04454: pdf, ps.