CrossRef
Open Access
2023
1 sitasi
On the existence of uncountable Hopfian and co-Hopfian abelian groups
Gianluca Paolini
Saharon Shelah
Abstrak
AbstractWe deal with the problem of existence of uncountable co-Hopfian abelian groups and (absolute) Hopfian abelian groups. Firstly, we prove that there are no co-Hopfian reduced abelian groups G of size < p with infinite Torp(G), and that in particular there are no infinite reduced abelian p-groups of size < p. Secondly, we prove that if $${2^{{\aleph _0}}} < \lambda < {\lambda ^{{\aleph _0}}}$$ 2 ℵ 0 < λ < λ ℵ 0 , and G is abelian of size λ, then G is not co-Hopfian. Finally, we prove that for every cardinal λ there is a torsion-free abelian group G of size λ which is absolutely Hopfian, i.e., G is Hopfian and G remains Hopfian in every forcing extension of the universe.
Penulis (2)
G
Gianluca Paolini
S
Saharon Shelah
Akses Cepat
Informasi Jurnal
- Tahun Terbit
- 2023
- Bahasa
- en
- Total Sitasi
- 1×
- Sumber Database
- CrossRef
- DOI
- 10.1007/s11856-023-2534-4
- Akses
- Open Access ✓