1. On extensions of primary almost totally projective abelian groups
- Creator:
- Danchev, Peter Vassilev
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- totally projective group, almost totally projective group, countable group, and extension
- Language:
- English
- Description:
- Suppose G is a subgroup of the reduced abelian p-group A. The following two dual results are proved: (∗) If A/G is countable and G is an almost totally projective group, then A is an almost totally projective group. (∗∗) If G is countable and nice in A such that A/G is an almost totally projective group, then A is an almost totally projective group. These results somewhat strengthen theorems due to Wallace (J. Algebra, 1971) and Hill (Comment. Math. Univ. Carol., 1995), respectively.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public