On inseparable descent
A ring extension is said to be strongly affine if each -subalgebra of is a finite-type -algebra. In this paper, several characterizations of strongly affine extensions are given. For instance, we establish that if is a quasi-local ring of finite dimension, then is integrally closed and strongly affine if and only if is a Prüfer extension (i.e. is a normal pair). As a consequence, the equivalence of strongly affine extensions, quasi-Prüfer extensions and INC-pairs is shown. Let be...
Let be a commutative ring with an identity different from zero and be a positive integer. Anderson and Badawi, in their paper on -absorbing ideals, define a proper ideal of a commutative ring to be an -absorbing ideal of , if whenever for , then there are of the ’s whose product is in and conjecture that for any ideal of an arbitrary ring , where . In the present paper, we use content formula techniques to prove that their conjecture is true, if one of the following conditions...
A ring extension is said to be FO if it has only finitely many intermediate rings. is said to be FC if each chain of distinct intermediate rings in this extension is finite. We establish several necessary and sufficient conditions for the ring extension to be FO or FC together with several other finiteness conditions on the set of intermediate rings. As a corollary we show that each integrally closed ring extension with finite length chains of intermediate rings is necessarily a normal pair...