- International Electronic Journal of Algebra
- Volume:21 Issue:21
- PROPERTIES OF RING EXTENSIONS INVARIANT UNDER GROUP ACTION
PROPERTIES OF RING EXTENSIONS INVARIANT UNDER GROUP ACTION
Authors : Amy Schmidt
Pages : 39-54
Doi:10.24330/ieja.295752
View : 15 | Download : 10
Publication Date : 2017-01-17
Article Type : Research Paper
Abstract :Let G be a subgroup of the automorphism group of a commutative ring with identity T. Let R be a subring of T. We show that RG ⊂ T G is a minimal ring extension whenever R ⊂ T is a minimal extension under various assumptions. Of the two types of minimal ring extensions, integral and integrally closed, both of these properties are passed from R ⊂ T to RG ⊆ T G. An integrally closed minimal ring extension is a flat epimorphic extension as well as a normal pair. We show that each of these properties also pass from R ⊂ T to RG ⊆ T G under certain group action.Keywords : Fixed ring, ring of invariants