There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Commutative ring theory: Regular rings

The Algebraic Theory of Semigroups, Vol. I. By A. H. Clifford and G. B. Preston. Pp. xv + 224. $10.60. 1961. (American Mathematical Society, Providence.)

Commutative rings I

In this work, we construct a class of Armendariz rings and a class of non-Armendariz rings. For this we study the transfer of the Armendariz property to trivial ring extension and direct product. The article includes a brief discussion of the scope and precision of our results.

On Armendariz rings.

This paper investigates coherent-like conditions and related properties that a trivial extension R ≔ A ∝ E might inherit from the ring A for some classes of modules E. It captures previous results dealing primarily with coherence, and also establishes satisfactory analogues of well-known coherence-like results on pullback constructions. Our results generate new families of examples of rings (with zerodivisors) subject to a given coherent-like condition.

Trivial Extensions Defined by Coherent-like Conditions

Introduction.- 1. Principal-like Ideals and Related Polynomial Content Conditions (D.D. Anderson).- 2. Zero-divisor Graphs in Commutative Rings (D.F. Anderson, M. Axtell, J. Stickles).- 3. Class Semigroups and T-class Semigroups of Domains (S. Bazzoni, S. Kabbaj).- 4. Forcing Algebras, Syzygy Bundles, and Tight Closure (H. Brenner).- 5. Beyond Totally Reflexive Modules and Back: A Survey on Gorenstein Dimensions (L.W. Christensen, H.B. Foxby, H. Holm).- 6. On V-domains: A Survey (M. Fontana, M. Zafrullah).- 7. Tensor Products of Algebras Over a Field (H. Haghighi, M. Tousi, S. Yassemi).- 8. Multiplicative Ideal Theory in the Context of Commutative Monoids (F. Halter-Koch).- 9. Projectively-Full Ideals and Compositions of Consistent Systems of Rank One Discrete Valuation Rings: A Survey (W. Heinzer, J. Ratliff, D. Rush).- 10. Direct-sum Behavior of Modules Over One-dimensional Rings (R. Karr, R. Wiegand).- 11. The Defect (F.V. Kuhlmann).- 12. The Use of Ultrafilters to Study the Structure of a Commutative Ring (K.A. Loper).- 13. Integrally Closed Overrings of Two-dimensional Noetherian Domains (B. Olberding).- 14. Almost Perfect Domains and Their Modules (L. Salce).- 15. Characteristic p Methods in Characteristic Zero via Ultraproducts (H. Schoutens).- 16. Rees Valuations (I. Swanson).- 17. Weak Normality and Seminormality (M. Vitulli).

Commutative Algebra: Noetherian and non-Noetherian Perspectives

This paper deals with well-known extensions of the Prufer domain concept to arbitrary commutative rings. We investigate the transfer of these notions in trivial ring extensions (also called idealizations) of commutative rings by modules and then generate original families of rings with zerodivisors subject to various Prufer conditions. The new examples give further evidence for the validity of Bazzoni-Glaz conjecture on the weak dimension of Gaussian rings. Moreover, trivial ring extensions allow us to widen the scope of validity of Kaplansky-Tsang conjecture on the content ideal of Gaussian polynomials.

Salah-Eddine Kabbaj

Papers

Trivial Extensions Defined by Coherent-like Conditions

Commutative Algebra: Noetherian and non-Noetherian Perspectives

Trivial extensions defined by Prufer conditions

Trivial extensions defined by Prüfer conditions

Commutative rings in which every finitely generated ideal is quasi-projective