| Title: | Extending subgroup and subring isomorphisms to automorphisms (English) |
| Author: | Oman, Greg |
| Language: | English |
| Journal: | Czechoslovak Mathematical Journal |
| ISSN: | 0011-4642 (print) |
| ISSN: | 1572-9141 (online) |
| Volume: | 76 |
| Issue: | 3 |
| Year: | 2026 |
| Pages: | 747-762 |
| Summary lang: | English |
| . | |
| Category: | math |
| . | |
| Summary: | Let $G$ be an Abelian group. Then $G$ is called a $T_1'$ group provided that for every pair of isomorphic subgroups $H$ and $K$ of $G$ and every isomorphism $\varphi \colon H\to K$, $\varphi $ can be extended to an automorphism of $G$. Let us call $G$ a weakly $T_1'$ group if for any elements $a$ and $b$ of $G$ of the same order, there is an automorphism $\varphi \colon G\to G$ such that $\varphi (a)=b$. We determine both classes of groups, correcting a result in the literature. We then study several analogues for rings. (English) |
| Keyword: | automorphism |
| Keyword: | Boolean ring |
| Keyword: | divisible Abelian group |
| Keyword: | Galois ring |
| Keyword: | homococyclic group |
| Keyword: | injective hull |
| Keyword: | $p$-component |
| Keyword: | quasi-cyclic group |
| Keyword: | uniserial ring |
| MSC: | 16D50 |
| MSC: | 20K27 |
| MSC: | 20K30 |
| DOI: | 10.21136/CMJ.2026.0475-24 |
| . | |
| Date available: | 2026-09-11T13:10:28Z |
| Last updated: | 2026-09-14 |
| Stable URL: | http://hdl.handle.net/10338.dmlcz/153726 |
| . | |
| Reference: | [1] Chang, C. C., Keisler, H. J.: Model Theory.Studies in Logic and the Foundations of Mathematics 73. North-Holland, Amsterdam (1973). Zbl 0276.02032, MR 0409165 |
| Reference: | [2] Chekhlov, A. R.: On direct sums of cyclic groups with invariant monomorphisms.Vestn. Tomsk. Gos. Univ., Mat. Mekh. 2013 (2013), 60-65 Russian. Zbl 07607416 |
| Reference: | [3] Fuchs, L.: Abelian Groups.Publishing House of the Hungarian Academy of Sciences, Budapest (1958). Zbl 0091.02704, MR 0106942, 10.1007/978-3-319-19422-6 |
| Reference: | [4] Hausen, J., Johnson, J. A.: Abelian groups with many automorphisms.Rend. Sem. Mat. Univ. Padova 55 (1976), 1-5. Zbl 0358.20062, MR 0466349 |
| Reference: | [5] Hungerford, T. W.: Algebra.Graduate Texts in Mathematics 73. Springer, New York (1980). Zbl 0442.00002, MR 0600654, 10.1007/978-1-4612-6101-8 |
| Reference: | [6] Jech, T.: Set theory.Springer Monographs in Mathematics. Springer, Berlin (2003). Zbl 1007.03002, MR 1940513, 10.1007/3-540-44761-X |
| Reference: | [7] Koppelberg, S.: Handbook of Boolean Algebras. Volume 1.North-Holland, Amsterdam (1989). Zbl 0671.06001, MR 0991565 |
| Reference: | [8] Lang, S.: Algebra.Graduate Texts in Mathematics 211. Springer, New York (2002). Zbl 0984.00001, MR 1878556, 10.1007/978-1-4613-0041-0 |
| Reference: | [9] McDonald, B. R.: Finite Rings with Identity.Pure and Applied Mathematics 28. Marcel Dekker, Berlin (1974). Zbl 0294.16012, MR 0354768 |
| Reference: | [10] Mishina, A. P.: Abelian groups.J. Sov. Math. 18 (1982), 629-668. Zbl 0479.20024, MR 0584568, 10.1007/BF01091961 |
| Reference: | [11] Shultz, P.: Automorphism Groups of Abelian Groups: Thesis.University of Western Australia, Perth (2000). |
| . |
Fulltext not available (moving wall 24 months)