EXISTENTIALLY AND κ-EXISTENTIALLY CLOSED GROUPS
International Journal of Group Theory, cilt.12, sa.1, ss.45-54, 2023 (ESCI, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 12 Sayı: 1
- Basım Tarihi: 2023
- Doi Numarası: 10.22108/ijgt.2022.131513.1758
- Dergi Adı: International Journal of Group Theory
- Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus, Academic Search Premier, zbMATH, Directory of Open Access Journals
- Sayfa Sayıları: ss.45-54
- Anahtar Kelimeler: algebraically closed groups, automorphism groups, Existentially closed groups
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
A group G is existentially closed (algebraically closed) if every finite system of equations and in-equations that has coefficients in G and has a solution in an overgroup H ≥ G has a solution in G. Existentially closed groups were introduced by W. R. Scott in 1951. B. H. Neumann posed the following question in 1973: Does there exist explicit examples of existentially closed groups? Generalized version of this question is as follows: Let κ be an infinite cardinal. Does there exist explicit examples of κ-existentially closed groups? Recently an affirmative answer was given to Neumann’s question and the generalized version of it, by Kaya-Kegel-Kuzucuoğlu. We give a survey of these results. We also prove that, there are maximal subgroups of κ-existentially existentially closed groups and provide some information about subgroups containing the centralizer of subgroups generated by fewer than κ-elements. This generalizes a result of Hickin-Macintyre.