中文

Type Two Cuts, Bad Cuts and Very Bad Cuts

逻辑 2008-02-03 v1

摘要

Type two cuts, bad cuts and very bad cuts are introduced by Keisler and Leth for studying the relationship between Loeb measure and U-topology of a hyperfinite time line in an ω1\omega_1-saturated nonstandard universe. The questions concerning the existence of those cuts are asked there. In this paper we answer, fully or partially, some of those questions by showing that: (1) type two cuts exist in any nonstandard model of Peano Arithmetic, (2) the 1\aleph_1-isomorphism property implies that bad cuts exist, but no bad cuts are very bad.

引用

@article{arxiv.math/9604210,
  title  = {Type Two Cuts, Bad Cuts and Very Bad Cuts},
  author = {R. Jin},
  journal= {arXiv preprint arXiv:math/9604210},
  year   = {2008}
}