Sh:1223

• Golshani, M., & Shelah, S. (2023). The Keisler-Shelah isomorphism theorem and the continuum hypothesis II. Monatshefte Fur Mathematik, 201, 789–801. arXiv: 2112.15468 MR: 4595008
• Abstract:
  We continue the investigation started in [Sh:1215] about the relation between the Keilser-Shelah isomorphism theorem and the continuum hypothesis. In particular, we show it is consistent that the continuum hypothesis fails and for any given sequence \langle (\mathbb{M}^{1}_n, \mathbb{M}^{2}_n: n < \omega \rangle of models of size at most \aleph_1 in a countable language, if the sequence satisfies a mild extra property, then for every non-principal ultrafilter \mathcal D on \omega, if the ultraproducts \prod\limits_{\mathcal D} \mathbb{M}^{1}_n and \prod\limits_{\mathcal D} \mathbb{M}^{2}_n are elementarily equivalent, then they are isomorphic.
• Version 2022-08-30_2 (16p)

@article{Sh:1223,
 author = {Golshani, Mohammad and Shelah, Saharon},
 title = {{The Keisler-Shelah isomorphism theorem and the continuum hypothesis II}},
 journal = {Monatshefte fur Mathematik,},
 volume = {201},
 year = {2023},
 pages = {789-801},
 mrnumber = {4595008},
 note = {\href{https://arxiv.org/abs/2112.15468}{arXiv: 2112.15468}},
 arxiv_number = {2112.15468}
}