# Sh:1132

- Saveliev, D. I., & Shelah, S. (2019).
*Ultrafilter extensions do not preserve elementary equivalence*. MLQ Math. Log. Q.,**65**(4), 511–516. arXiv: 1712.06198 MR: 4057949 -
Abstract:

We show that there exist models {\mathcal M}_1 and {\mathcal M}_2 such that {\mathcal M}_1 elementarily embeds into {\mathcal M}_2 but their ultrafilter extension \beta({\mathcal M}_1) and \beta({\mathcal M}_2) are not elementarily equivalent. - published version (6p)

Bib entry

@article{Sh:1132, author = {Saveliev, Denis I. and Shelah, Saharon}, title = {{Ultrafilter extensions do not preserve elementary equivalence}}, journal = {MLQ Math. Log. Q.}, fjournal = {MLQ. Mathematical Logic Quarterly}, volume = {65}, number = {4}, year = {2019}, pages = {511--516}, issn = {0942-5616}, mrnumber = {4057949}, mrclass = {03C55 (03C30 03C80 54D35 54D80 54H10)}, note = {\href{https://arxiv.org/abs/1712.06198}{arXiv: 1712.06198}}, arxiv_number = {1712.06198} }