F-Noetherian Rings and Skew Quantum Ring Extensions

Abstract

A ring R shall be called F-noetherian if every finite subset of R is contained in a (left and right) noetherian subring of R . For example, every commutative ring is tightly F-noetherian in the sense that every finite subset of R generates a noetherian subring of R . F-noetherian rings have many interesting linear algebra properties which we refer to as the full strong rank condition, fully stably finite, and more generally the basic condition. We also study some basic ring-theoretic properties of F-noetherian rings such as localizations of F-noetherian rings. The F-noetherian property is preserved under some \emph{skew} quantum ring extensions including some iterated Ore extensions, some skew-Laurent extensions, and some quantum almost-normalizing extensions. For example, let R= S[ x_1, ..., x_n ] be a finitely generated ring \textit {over a subring S} such that (1) for i < j, \[ x_j x_i -q_{ji} x_i x_j \in S [ x_1, ..., x_{j-1}] + Sx_j \] for some units q_{ji} \in S, (2) for all i, Sx_i +S= S+ x_i S, and (3) each x_i commutes with a subring A of S such that S is finitely generated as a ring over A . Then, if S is F-noetherian, so is R . We also discuss some skew quadratic extensions related to the quantum group \mathcal{O}_q(G) where G is a connected complex semisimple algebraic group. Finally, we show many examples and some generalizations of some quantum groups like \mathcal{O}_q(M_n(k)) over an F-noetherian ring k where each variable x_{ij} \textit{may not commute} with the elements of k .