Structure of noetherian prime rings

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In 2002, Anderson and Dumitrescu introduced [Formula: see text]-Noetherian rings, a significant advancement in ring theory. Later, in 2018, Bennis and El Hajoui expanded on this by introducing two new classes of rings that generalize the concept of coherent rings: [Formula: see text]-coherent rings, where every finitely generated ideal is [Formula: see text]-finitely presented, and [Formula: see text]-[Formula: see text]-coherent rings, where every [Formula: see text]-finite ideal is [Formula: see text]-finitely presented. This paper builds on these concepts to introduce the [Formula: see text]-[Formula: see text]-(weak) global dimension for rings with a multiplicative subset [Formula: see text], offering a new perspective on ring structures. We also explore [Formula: see text]-[Formula: see text]-variants of specific ring types, including semisimple, von Neumann, and (semi)hereditary rings. Finally, we extend the generalization of [Formula: see text]-rings and [Formula: see text]-coherent rings, originally introduced by Costa in 1994, to rings with a multiplicative subset [Formula: see text], deepening the understanding of ring theory.

The concept of a quiver, i.e., a direct graph of a finite-dimensional algebra, was introduced by Gabriel in connection with problems of representation theory of such algebras. The notion of a scheme (=quiver Q(A)) of a semiperfect, right Noetherian ring A was introduced by the author and was applied to the study of the structure of serial rings. We give a short review of some results on structural ring theory, which were obtained by using the graph technique.

Principal ideal theorem for Noetherian P. I. rings

Centers and prime ideals in group algebras of polycyclic-by-finite groups

Ideal arithmetic in noetherian Pi rings

We study classical right quotient rings and ordinary extensions of various kinds of 2-primal rings, constructing examples for situations that raise naturally in the process. We show: (1) Let R be a right Ore ring with P(R) left T-nilpotent. Then Q is a 2-primal local ring with P(Q)=J(Q) = {ab-1 ∈ Q | a ∈ P(R), b ∈ C(0)} if and only if C(0)=C(P(R))=R∖P(R), where Q is the classical right quotient ring of R. (2) Let R be a right Ore ring. Then R[x] is a domain whose classical right quotient ring is a division ring if and only if R is a right p.p. ring with C(P(R))=R∖P(R). As a consequence, if R is a right Noetherian ring, then R[[x]] is a domain whose classical right quotient ring is a division ring if and only if R[x] is a domain whose classical right quotient ring is a division ring if and only if R is a right p.p. ring with C(P(R))=R∖P(R).

Let K be a field and K[x] the polynomial ring over K in an indeterminate x. If P is a prime ideal of K[x], then there exists an irreducible polynomial f in K[x] such that P = K[x]f. This result is quite old and basic; however no corresponding result seems to be known for a polynomial ring in n indeterminates x1, ..., xn over K. Actually, it seems to be very difficult to find some system of generators for a prime ideal of K[xl,...,Xn]. Now, K [x1, ..., xn] is a Noetherian ring and by a converse of the principal ideal theorem for every prime ideal P of K[x1, ..., xn] there exist n polynomials fi, f..n such that P is minimal over (fi, ..., fn), the ideal generated by { fl, ..., f}n ([4], Theorem 153). Also, as a consequence of ([1], Theorem 1) it follows that any prime ideal of K[xl, X.., Xn] is determined by n polynomials. However it is not clear in [1] how to find these polynomials and no converse result is proved. The purpose of this paper is to show a result which in particular implies that every prime ideal of K[xi, ..., xn] is determined by a sequence of n polynomials which is in some sense irreducible, and such that the converse is also true. In general, let R be any prime ring. If P is a nonzero prime ideal of the polynomial ring R[x] with P n R = 0 (an R-disjoint prime ideal), then P = Q[x]fo n R[x] where Q is a ring of right quotients of R and fo E C[x] is an irreducible polynomial, C being the extended centroid of R ([2], Corollary 2.7). This characterization has the problem that we have to compute Q to have a prime ideal determined. A better way (an intrinsic one) to determine an R-disjoint prime ideal has been given in [3]. We proved that every R-disjoint prime ideal P of R[x] is determined by just one polynomial in P which is in some sense irreducible ([3], Theorem 1.4).

Let R be a ring. An element p of R is a prime element if pR = Rp is a prime ideal of R. A prime ring R is said to be a Unique Factorisation Ring if every non-zero prime ideal contains a prime element. This paper develops the basic theory of U.F.R.s. We show that every polynomial extension in central indeterminates of a U.F.R. is a U.F.R. We consider in more detail the case when a U.F.R. is either Noetherian or satisfies a polynomial identity. In particular we show that such a ring R is a maximal order, that every height-1 prime ideal of R has a classical localisation in which every two-sided ideal is principal, and that R is the intersection of a left and right Noetherian ring and a simple ring.

Modules with serial Noetherian endomorphism rings

We consider the Grothendieck group G 0 {G_0} of various graded rings, including G 0 ( A n r ) {G_0}(A_n^r) where A is a commutative noetherian ring, and A n r A_n^r is the A-subalgebra of the polynomial ring A [ X 0 , … , X n ] A[{X_0}, \ldots ,{X_n}] generated by monomials of degree r. If A is regular, then G 0 ( A n r ) {G_0}(A_n^r) has a ring structure. The ideal class groups of these rings are also considered.

In this paper we obtain results on normal subgroups in semi prime rings which enable us to extend results in [3] on the solvability of normal subgroups and results in [4] on conjugates of noncentral elements. The main tool in our investigation is the recent work of Herstein [2] on the Lie structure of semi prime rings. To use these results we must make an assumption which guarantees a rich supply of elements of square zero, and so, a rich supply of units. Some such assumption is necessary as illustrated by our example in [-4] which shows that even in a prime ring with zero divisors the group of units can be abelian and can centralize noncentral elements, even in the presence of an infinite collection of independent elements of square zero.

In this note we extend the Lie inner ideal structure of simple Artinian rings with involution, initiated by Benkart and completed by Benkart and Fernández López, to centrally closed prime rings with involution of characteristic not 2 2 , 3 3 or 5 5 . New Lie inner ideals (which we call special) occur when making this extension. We also give a purely algebraic description of the so-called Clifford inner ideals, which had only been described in geometric terms.

We are mainly interested in the study of prime and semi-prime rings and their rings of quotients. However, our argument proceeds largely in the category of modules (§ 1 to 4) and bimodules (§ 5 to 7).After a brief description of the generalized rings of quotients introduced recently by Johnson, Utumi, and Findlay and the present author, we study a closure operation on the lattice of submodules of a module. For the lattice of left ideals of a ring, the concept of closed submodules reduces to the If-ideals of Utumi. The lattice of closed submodules of a module is always a complete modular lattice. We are specially interested in the case when it is a complemented lattice. This happens, in particular, when the singular submodule of Johnson and Wong vanishes. We consider the lattice of closed right ideals of a prime ring S and determine the maximal ring of right quotients of S in the case when this lattice has atoms.

In this note we present an extremely short proof of Goldie's theorem on the structure of semiprime Noetherian rings [1]. The outline of the proof was given by Procesi and Small in [4]. By utilizing the concept of the singular ideal of a ring we have been able to weaken the hypotheses of many of the steps in [4]. Most significantly, we are able to avoid a reduction to the case of prime rings, and in Lemma 5 we give an informative list of the relationship between regular elements and essential ideals of semiprime rings.