Sh:1029

• Shelah, S. (2016). No universal group in a cardinal. Forum Math., 28(3), 573–585. arXiv: 1311.4997 DOI: 10.1515/forum-2014-0040 MR: 3510831
• Abstract:
  For many classes of models there are universal members in any cardinal \lambda which "essentially satisfied GCH", i.e. \lambda = 2^{< \lambda}. But if the class is "complicated enough", e.g. the class of linear orders, we know that if \lambda is "regular and not so close to satisfying GCH" then there is no universal member. Here we find new sufficient conditions (which we call the olive property), not covered by earlier cases (i.e. fail the so-called SOP_4). The advantage of those conditions is witnessed by proving that the class of groups satisfies one of those conditions.
• Version 2023-05-16 (20p) published version (13p)

@article{Sh:1029,
 author = {Shelah, Saharon},
 title = {{No universal group in a cardinal}},
 journal = {Forum Math.},
 fjournal = {Forum Mathematicum},
 volume = {28},
 number = {3},
 year = {2016},
 pages = {573--585},
 issn = {0933-7741},
 mrnumber = {3510831},
 mrclass = {03C45 (03C50 03C55 03C65 03E04 03E75 20A15)},
 doi = {10.1515/forum-2014-0040},
 note = {\href{https://arxiv.org/abs/1311.4997}{arXiv: 1311.4997}},
 arxiv_number = {1311.4997}
}