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When multiplication of topologizing filters is commutative. (English) Zbl 0949.16029

Let \(R\) be a ring with identity, and let \(\text{Fil }R\) denote the set of all right topologizing filters on \(R\). \(\text{Fil }R\) is isomorphic as a complete lattice and a semigroup to \(\text{torsp }R\), the set of torsion preradicals of \(R\). If \(R=K[x;\alpha]\) for a field \(K\) and an endomorphism \(\alpha\) of \(K\), then \(\text{Fil }R\) is commutative only if \(\alpha\) is an automorphism. If \(R\) is a right FBN ring such that \(IK=KI\) for every pair of ideals \(I,K\) of \(R\), then every finitely generated uniform right \(R\)-module is decisive in the sense of J. S. Golan [Torsion theories, Pitman Monogr. Surv. Pure Appl. Math. 29 (1986; Zbl 0657.16017)] and \(R\) satisfies the Jacobson Conjecture. If \(\text{Fil }R\) is commutative, then \(R\) satisfies the ACC on annihilator ideals, the prime radical of \(R\) is nilpotent, and \(I_R\) is finitely annihilated whenever \(I\) is an ideal of \(R\). A (semi) prime ring for which \(\text{Fil }R\) is commutative is right strongly (semi) prime. If \(R\) is a commutative domain and \(\text{Fil }R\) is commutative, then \(R\) satisfies the ACC on principal ideals. If \(R\) is commutative and \(\text{Fil }R\) is commutative, then \(R\) is semistable in the sense of Golan [op. cit.], \(\text{Ass }M\neq\emptyset\) for all nonzero modules \(M\), and every indecomposable injective module has the form \(E(R/P)\) for some prime ideal \(P\).

MSC:

16S90 Torsion theories; radicals on module categories (associative algebraic aspects)
16N60 Prime and semiprime associative rings
16N20 Jacobson radical, quasimultiplication
16P40 Noetherian rings and modules (associative rings and algebras)
16P60 Chain conditions on annihilators and summands: Goldie-type conditions
13C11 Injective and flat modules and ideals in commutative rings
13E99 Chain conditions, finiteness conditions in commutative ring theory

Citations:

Zbl 0657.16017
Full Text: DOI