Mathematics â€ș Algebra and Number Theory

Rings, Modules, and Algebras

Description

This cluster of papers focuses on the study of properties and structures of commutative rings, including topics such as zero-divisor graphs, Armendariz rings, idealization, Baer rings, nil-clean rings, annihilator ideals, quasi-Baer rings, factorization theory, triangular matrix representations, and semistar operations.

Keywords

Zero-Divisor Graphs; Armendariz Rings; Idealization; Baer Rings; Nil-Clean Rings; Annihilator Ideals; Quasi-Baer Rings; Factorization Theory; Triangular Matrix Representations; Semistar Operations

Commutative domains and their modules Valuation domains Prufer domains More non-Noetherian domains Finitely generated modules Projectivity and projective dimension Divisible modules Topology and filtration Injective modules Uniserial modules Heights, invariants 
 Commutative domains and their modules Valuation domains Prufer domains More non-Noetherian domains Finitely generated modules Projectivity and projective dimension Divisible modules Topology and filtration Injective modules Uniserial modules Heights, invariants and basic submodules Polyserial modules RD- and pure-injectivity Torsion modules Torsion-free modules of finite rank Infinite rank torsion-free modules Appendix on set theory Bibliography Author index Subject index.
contenir la présente mention de copyright. contenir la présente mention de copyright.
This volume provides a comprehensive introduction to module theory and the related part of ring theory, including original results as well as the most recent work. It is a useful 
 This volume provides a comprehensive introduction to module theory and the related part of ring theory, including original results as well as the most recent work. It is a useful and stimulating study for those new to the subject as well as for researchers and serves as a reference volume. Starting form a basic understanding of linear algebra, the theory is presented and accompanied by complete proofs. For a module M, the smallest Grothendieck category containing it is denoted by o[M] and module theory is developed in this category. Developing the techniques in o[M] is no more complicated than in full module categories and the higher generality yields significant advantages: for example, module theory may be developed for rings without units and also for non-associative rings. Numerous exercises are included in this volume to give further insight into the topics covered and to draw attention to related results in the literature.
Serre [9, §50] has shown that there is a one-to-one correspondence between algebraic vector bundles over an affine variety and finitely generated projective modules over its coordinate ring.For some time, 
 Serre [9, §50] has shown that there is a one-to-one correspondence between algebraic vector bundles over an affine variety and finitely generated projective modules over its coordinate ring.For some time, it has been assumed that a similar correspondence exists between topological vector bundles over a compact Hausdorff space X and finitely generated projective modules over the ring of continuous real-valued functions on X.A number of examples of projective modules have been given using this correspondence.However, no rigorous treatment of the correspondence seems to have been given.I will give such a treatment here and then give some of the examples which may be constructed in this way.1. Preliminaries.Let K denote either the real numbers, complex numbers or quaternions.A X-vector bundle ÂŁ over a topological space X consists of a space F(ÂŁ) (the total space), a continuous map p : E(Ç) -+ X (the projection) which is onto, and, on each fiber Fx(ÂĄz) = p-1(x), the structure of a finite dimensional vector space over K.These objects are required to satisfy the following condition: for each xeX, there is a neighborhood U of x, an integer n, and a homeomorphism <p:p-1(U)-> U x K" such that on each fiber <b is a X-homomorphism.The fibers u x Kn of U x K" are X-vector spaces in the obvious way.Note that I do not require n to be a constant.The dimension of the fiber Fx may vary with x.However, this dimension is clearly locally constant and so will be constant if X is connected.A subbundle of t] is, by definition, a subset Ex <= E (Ç) such that Ex n Fx is a X-subspace of Fx for each x and such that Ex with the projection p | Ex and the X-structure on its fibers induced by that of E forms a X-vector bundle over X.A map of X-vector bundles /:{-»i; is defined to be a continuous map f:E(Ç)-+E(n) such that pf' = p and such that /| Fx(0 : Fx(0 -â–ș Fx(n) is a Xhomomorphism.It is clear that the X-vector bundles over X and their maps form an additive category.A section s of {; over a subset A cz X is a continuous map s : A -+ ÂŁ(ÂŁ) such that ps(x) = x.It follows immediately from the definition of a vector bundle that for any xeX, there is a neighborhood U of x and sections sx, ...,s" of ÂŁ
This series aims to report new developments in mathematical research and teaching -quickly, informally and at a high level.The type of material considered for publication includes: 1.Preliminary drafts of original 
 This series aims to report new developments in mathematical research and teaching -quickly, informally and at a high level.The type of material considered for publication includes: 1.Preliminary drafts of original papers and monographs 2. Lectures on a new field, or presenting a new angle on a classical field 3. Seminar work-outs 4. Reports of meetings, provided they are a) of exceptional interest or b) devoted to a single topic.
Introduction.It is a well-known and basic result of homological algebra that the direct product of an arbitrary family of injective modules over any ring is again injective [3, p. 8].Such 
 Introduction.It is a well-known and basic result of homological algebra that the direct product of an arbitrary family of injective modules over any ring is again injective [3, p. 8].Such is not the case for projective modules, as is evidenced, for example, by a result of Baer [7, p. 48] which states that the direct product of a countably infinite number of copies of the ring of rational integers is not a free abelian group.It is thus natural to ask for the precise ideal-theoretic conditions which are forced upon a ring by the requirement that its projective modules be preserved by direct products in the manner just described.In this paper we shall present a solution to this problem, as well as an answer to the corresponding question for flat modules.We then exhibit several applications of these results.First, we derive information concerning semi-hereditary rings which, when applied to integral domains, yields immediately characterizations of PrĂŒfer rings due to Hattori [5] (see also [6]).The second application also concerns integral domains.Let us call a torsion module over an integral domain ÂŁ a UT-module if it is a direct summand of every ÂŁ-module of which it is the torsion submodule.We prove that, if every ÂŁ-module of bounded order is a UT-module, then ÂŁ must be a Dedekind ring (the converse is well-known; see [8, p. 334]).As a final application, we obtain a partial solution to the following question of Köthe [9]: For which rings ÂŁ is it true that every left ÂŁ-module is a direct sum of cyclic modules?We prove that, if ÂŁ has the weaker property that every left ÂŁ-module is a direct sum of finitely generated modules, then ÂŁ satisfies the minimum condition on left ideals and every indecomposable injective left ÂŁ-module has finite length.This generalizes a result of Kaplansky and Cohen [4].Our investigations along these lines were motivated to some extent by the interesting observation of Bass [2] that left Noetherian rings are characterized by the property that their injective left modules are preserved by direct sums.We have, with his kind permission, included this in our paper, as we shall need it in the proof of another result.
This second volume deals with the relative homological algebra of complexes of modules and their applications. It is a concrete and easy introduction to the kind of homological algebra which 
 This second volume deals with the relative homological algebra of complexes of modules and their applications. It is a concrete and easy introduction to the kind of homological algebra which has been developed in the last 50 years. The book serves as a bridge between the traditional texts on homological algebra and more advanced topics such as triangulated and derived categories or model category structures. It addresses to readers who have had a course in classical homological algebra, as well as to researchers.
* Introduction * Rings and Ideals * Modules * Rings and Modules of Fractions * Primary Decomposition * Integral Dependence and Valuations * Chain Conditions * Noetherian Rings * Artin 
 * Introduction * Rings and Ideals * Modules * Rings and Modules of Fractions * Primary Decomposition * Integral Dependence and Valuations * Chain Conditions * Noetherian Rings * Artin Rings * Discrete Valuation Rings and Dedekind Domains * Completions * Dimension Theory
Let r be a ring having center C and let A be a C-subalgebra of I\ Then T may be considered a two-sided A-module.It Let r be a ring having center C and let A be a C-subalgebra of I\ Then T may be considered a two-sided A-module.It
The notations of the present paper are largely determined by the usages already established in R. Thus, for instance, in considering Boolean rings as abstract entities, we continue to use 
 The notations of the present paper are largely determined by the usages already established in R. Thus, for instance, in considering Boolean rings as abstract entities, we continue to use the symbols -, v , +, <, ' corresponding to the symbols ■, u , A, c, ', of the theory of classes.In the algebra of the closure operation, we write A~ in place of A for convenience in putting down the more complicated expressions such as A~'~'.The contents of the present paper may be summarized systematically under the following headings: Chapter I, Boolean spaces: §1, Introduction of topological concepts; §2, Relations between algebra and topology; §3, Universal Boolean rings and spaces.Chapter II, Maps in Boolean spaces: §1, The general theory of maps; §2, Construction of Boolean maps; §3, Relation between algebraic and other maps; §4, Applications to the theory of extensions; §5, Totally-disconnected and discrete spaces.Chapter III, «Stronger separation conditions: §1
Augustfunctor oĂź3/t\n if; also, we shall say that Fis a space-preserving functor from 38 to«".It turns out that Spec can be inverted on surprisingly large subcategories of ÂĄf.At this point, 
 Augustfunctor oĂź3/t\n if; also, we shall say that Fis a space-preserving functor from 38 to«".It turns out that Spec can be inverted on surprisingly large subcategories of ÂĄf.At this point, the results of §7 should be read as part of this introduction.In fact, after looking at §1, §2 and the results of §7, the reader can continue and finish the paper (except for the proof of Theorem 9 in §16), and then go back to the technical § §3-6 if he wishes.We note that §16 uses the functorial nature of our constructions to characterize the underlying spaces of preschemes and schemes.
by similar or dissimilar methodology now known or hereafter developed is forbidden. by similar or dissimilar methodology now known or hereafter developed is forbidden.
Introduction In this discussion every module over a ring R will be understood to be a left i2-module. R will always have a unit, and every module will be unitary. 
 Introduction In this discussion every module over a ring R will be understood to be a left i2-module. R will always have a unit, and every module will be unitary. The aim of this paper is to study the structure and properties of injective modules, particularly over Noetherian rings. B. Eckmann and A. Schopf have shown that if M is a module over any ring, then there exists a unique, minimal, injective module E(M) containing it. The module E(M) will be a major tool in our investigations, and we shall systematically exploit its properties. In § 1 we show that if a module M has a maximal, injective submodule C (as is the case for left-Noetherian rings), then C contains a carbon-copy of every injective submodule of M, and MjC has no injective submodules different from 0. Although C is unique up to an automorphism of My C does not in general contain every injective submodule of M, In fact, the sum of two injective submodules of a module is always injective if and only if the ring is left-heredita ry. In § 2 we show that for any ring R a module E is an indecomposable, injective module if and only if E = E(R\J)y where J is an irreducible, left ideal of R. We prove that if R is a left-Noetherian ring, then every injective Jϋ-module has a decomposition as a direct sum of indecomposable, injective submodules. Strong uniqueness assertions can be made concerning such decompositions over any ring. In § 3 we take R to be a commutative, Noetherian ring, and to be a prime ideal of R. We prove there is a one-to-one correspondence between the prime ideals of R and the indecomposable, injective Rmodules given by P**E(RjP). We examine the structure of the module E = E{RjP)y and show that if At is the annihilator in E of P then E = U At and -4ÎŻ+1/At is a finite dimensional vector space over the quotient field of R/P. The ring of iϋ-endomorphi sms of E is isomorphic in a natural way to Rp, the completion of the ring of quotients of R with respect to R-P. As an ^-module E is an injective envelope of RpjP, where is the maximal ideal of Rp. If is a maximal ideal of Ry then E is a countably generated ÎČ-module. Every indecomposable, injective i2-module is finitely generated if and only if R has the minimum condition on ideals. In § 4 we take R to be a commutative, Noetherian, complete, local ring, the maximal ideal of R and E = E{RjP). Then the eontravariant,
Idempotents can be lifted modulo a one-sided ideal <italic>L</italic> of a ring <italic>R</italic> if, given <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x element-of upper R"> <mml:semantics> <mml:mrow> <mml:mi>x</mml:mi> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mi>R</mml:mi> 
 Idempotents can be lifted modulo a one-sided ideal <italic>L</italic> of a ring <italic>R</italic> if, given <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x element-of upper R"> <mml:semantics> <mml:mrow> <mml:mi>x</mml:mi> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mi>R</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">x \in R</mml:annotation> </mml:semantics> </mml:math> </inline-formula> with <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x minus x squared element-of upper L"> <mml:semantics> <mml:mrow> <mml:mi>x</mml:mi> <mml:mo>−<!-- − --></mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi>x</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mi>L</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">x - {x^2} \in L</mml:annotation> </mml:semantics> </mml:math> </inline-formula>, there exists an idempotent <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="e element-of upper R"> <mml:semantics> <mml:mrow> <mml:mi>e</mml:mi> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mi>R</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">e \in R</mml:annotation> </mml:semantics> </mml:math> </inline-formula> such that <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="e minus x element-of upper L"> <mml:semantics> <mml:mrow> <mml:mi>e</mml:mi> <mml:mo>−<!-- − --></mml:mo> <mml:mi>x</mml:mi> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mi>L</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">e - x \in L</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. Rings in which idempotents can be lifted modulo every left (equivalently right) ideal are studied and are shown to coincide with the exchange rings of Warfield. Some results of Warfield are deduced and it is shown that a projective module <italic>P</italic> has the finite exchange property if and only if, whenever <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper P equals upper N plus upper M"> <mml:semantics> <mml:mrow> <mml:mi>P</mml:mi> <mml:mo>=</mml:mo> <mml:mi>N</mml:mi> <mml:mo>+</mml:mo> <mml:mi>M</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">P = N + M</mml:annotation> </mml:semantics> </mml:math> </inline-formula> where <italic>N</italic> and <italic>M</italic> are submodules, there is a decomposition <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper P equals upper A circled-plus upper B"> <mml:semantics> <mml:mrow> <mml:mi>P</mml:mi> <mml:mo>=</mml:mo> <mml:mi>A</mml:mi> <mml:mo>⊕<!-- ⊕ --></mml:mo> <mml:mi>B</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">P = A \oplus B</mml:annotation> </mml:semantics> </mml:math> </inline-formula> with <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper A subset-of-or-equal-to upper N"> <mml:semantics> <mml:mrow> <mml:mi>A</mml:mi> <mml:mo>⊆<!-- ⊆ --></mml:mo> <mml:mi>N</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">A \subseteq N</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper B subset-of-or-equal-to upper M"> <mml:semantics> <mml:mrow> <mml:mi>B</mml:mi> <mml:mo>⊆<!-- ⊆ --></mml:mo> <mml:mi>M</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">B \subseteq M</mml:annotation> </mml:semantics> </mml:math> </inline-formula>.
The purpose of this paper is to give the basis, and a few fundamental theorems, of a suggested systematic theory of semigroups. By a semigroup is meant a set S 
 The purpose of this paper is to give the basis, and a few fundamental theorems, of a suggested systematic theory of semigroups. By a semigroup is meant a set S closed to a single associative, binary multiplication. Two elements of S are said to be left equivalent (I) if they generate the same left ideal in S. Similarly a right equivalence (r) can be defined. These equivalences commute (or are associable, Dubreil, 1), and their product equivalence is denoted by b. The equivalence b is to be compared with the two-sided analogue f of I and r; x 3 y(f) means that x and y generate the same two-sided ideal. In the case where S is finite, these equivalences b and f coincide, but this is not true in general. A b-class has the property that the 1-classes which it contains generate isomorphic left ideals in S; a theorem on the structure of b-classes is given (Theorem 1). Schwarz (1) and Clifford (1, 3) have both made use of minimal conditions on right and left ideals; and Clifford has shown (1) that the minimum ideal of a semigroup, if it contains both minimal right, and minimal left ideals, is a simple subsemigroup of the type called by Rees completely simple (Rees, 1, 2). In his paper On Semigroups (Rees, 1), Rees determined the structure of such simple semigroups. The minimal conditions we use are more stringent, they are the minimal conditions on the partially ordered sets of the right, left and two-sided ideals. If the right and left conditions are satisfied, then so is the twosided condition (a fact not obvious in our case, since a two-sided ideal is not in general a right or left ideal). Further, in this case we do have b = f; and the b-classes take on a simpler aspect. The f-classes of any semigroup S correspond to semigroups called factors (cf. Rees, 1, p. 391) of S; our definition does not, however, depend on the existence of a principal series of ideals of S. We say that S is semisimple if all these factors are non-nilpotent semigroups. Another, and probably more fruitful idea, is that of regularity. The element a e S is regular if aza = a for some z e S; this is the condition introduced, for rings, by J. v. Neumann (1).1 A semigroup is regular, if all its elements are regular. Regular semigroups are semisimple, but not conversely; however, any semisimple semigroup which satisfies the right and left minimal conditions, is regular. It seems that these last-mentioned semigroups may form the class which will most repay study; the simple ones are completely simple (and therefore of known structure), and already the extension theory of Clifford (2) suggests the possibility of building up more
By A. Borel: pp. x, 398; Cloth $12.50, Paper $4.95. (W. A. Benjamin, Inc., New York, 1969). By A. Borel: pp. x, 398; Cloth $12.50, Paper $4.95. (W. A. Benjamin, Inc., New York, 1969).
Many basic definitions and results in the theory of near-rings can be found in G. Pilz ( 4 ). We follow these for the most part, except that we use 
 Many basic definitions and results in the theory of near-rings can be found in G. Pilz ( 4 ). We follow these for the most part, except that we use left near-rings rather than right near-rings. We follow exactly an earlier paper, Meldrum ( 2 ), where there are detailed definitions and many results relating to faithful d.g. near-rings. Let R be a d.g. near-ring, distributively generated by the semigroup S , which need not be the semigroup of all distributive elements. Denote such a d.g. near-ring by ( R, S ). Then ( R , +) = Gp &lt; S ; &gt; where is a set of defining relations in S . Let ( T, U ) be a d.g. near-ring. Then a d.g. homomorphism ξ from ( R, S ) to ( T, U ) is a near-ring homomorphism from R to T which satisfies Sξ ⊆ U . If ( G , +) is a group, let T 0 ( G ) be the near-ring of all maps from G to itself with pointwise addition and map composition. Let End G be the semigroup of all endomorphisms of G . Then ( E ( G ), End G ) is a d.g. near-ring. A d.g. near-ring ( R, S ) is faithful if there exists a d.g. monomorphism ξ:( R, S ) → ( E ( G ), End G ) for some group G .
This paper aims to associate a new graph to nonzero unital modules over commutative rings. Let R be a commutative ring having a nonzero identity and M be a nonzero 
 This paper aims to associate a new graph to nonzero unital modules over commutative rings. Let R be a commutative ring having a nonzero identity and M be a nonzero unital R-module. The zero intersection graph of annihilator ideals of R-module M, denoted by CR(M), is a simple (undirected) graph whose vertex set M⋆ = M − {0}, and two distinct vertices m and mâ€Č are adjacent if annR(m)∩annR(mâ€Č) = (0). We investigate the conditions under which CR(M) is a star graph, bipartite graph, complete graph, edgeless graph. Furthermore, we characterize certain classes of modules and rings such as torsion-free modules, torsion modules, semisimple modules, quasi-regular rings, and modules satisfying Property T in terms of their graphical properties.
Peter Danchev , L. Fuchs | BeitrÀge zur Algebra und Geometrie / Contributions to Algebra and Geometry
M. Sharma , R. Nath | Carpathian Mathematical Publications
Let $S$ be a subring of a finite ring $R$ and $r\in R$. The relative $r$-noncommuting graph of $R$ relative to $S$, denoted by $\Gamma_{S, R}^r$, is a simple undirected 
 Let $S$ be a subring of a finite ring $R$ and $r\in R$. The relative $r$-noncommuting graph of $R$ relative to $S$, denoted by $\Gamma_{S, R}^r$, is a simple undirected graph whose vertex set is $R$ and two vertices $x$ and $y$ are adjacent if and only if $x \in S$ or $y \in S$ and $[x,y] \neq r$, $[x,y]\neq -r$. In this paper, we determine degree of any vertex in $\Gamma_{S, R}^r$ and characterize all finite rings such that $\Gamma_{S, R}^r$ is a star, lollipop or a regular graph. We derive connections between relative $r$-noncommuting graphs of two isoclinic pairs of rings. We also derive certain relations between the number of edges in $\Gamma_{S, R}^r$ and various generalized commuting probabilities of $R$. Finally, we conclude the paper by studying an induced subgraph of $\Gamma_{S, R}^r$.
Mariam Pirashvili | Journal of Mathematical Sciences
In this paper, we define and study the X-subinjectivity domain of a module M where X=(A,B) is a complete cotorsion pair, which consists of those modules N such that, for 
 In this paper, we define and study the X-subinjectivity domain of a module M where X=(A,B) is a complete cotorsion pair, which consists of those modules N such that, for every extension K of N with K/N in A, any homomorphism f:N→M can be extended to a homomorphism g:K→M. This approach allows us to characterize some classical rings in terms of these domains and generalize some known results. In particular, we classify the rings with X-indigent modules—that is, the modules whose X-subinjectivity domains are as small as possible—for the cotorsion pair X=(FC,FI), where FI is the class of FP-injective modules. Additionally, we determine the rings for which all (simple) right modules are either X-indigent or FP-injective. We further investigate X-indigent Abelian groups in the category of torsion Abelian groups for the well-known example of the flat cotorsion pair X=(FL,EC), where FL is the class of flat modules.
Yota SHAMOTO | Bulletin de la Société mathématique de France
Shiksha Saini , Dinesh Udar | Czechoslovak Mathematical Journal
Several approaches to building generalized Pythagorean scales provide interpretation for the rational approximation of an irrational number. Generally, attention is paid to the convergents of the continued fraction expansions. The 
 Several approaches to building generalized Pythagorean scales provide interpretation for the rational approximation of an irrational number. Generally, attention is paid to the convergents of the continued fraction expansions. The present paper focuses on the sequences of semiconvergents corresponding to the alternating best one-sided approximations. These sequences are interpreted as scale lineages organized as a kinship. Their properties are studied in terms of the two types of tones and elementary intervals, since each scale contains the tones of the previous scale plus the newly added tones, i.e., the generic diatones and accidentals. For the last scale of a lineage, the octave is regularly subdivided by sections, separated by a single elementary interval of the other type. Lineages are therefore related to the scale diversity with regard to their generic diatones and accidentals, which is analyzed from the Shannon diversity index, either for tone abundance or interval occupancy.
In this paper, we introduce the tri-potent graph of a commutative ring R, denoted by TP(R), where two distinct vertices x and y in R are adjacent if and only 
 In this paper, we introduce the tri-potent graph of a commutative ring R, denoted by TP(R), where two distinct vertices x and y in R are adjacent if and only if (x + y)3 = x + y. We conduct a comprehensive investigation of the graphical structural properties of tri-potent graph of a commutative ring R, including its diameter, connectedness, and size. It is shown that the tri-potent graph of a commutative ring R contains cycles with girth 3 and has no end vertices. Furthermore, we describe a significant spanning subgraph of the tri-potent graph of a commutative ring R and analyze the degree of each vertex in detail. Finally, we establish that, for a specific local ring, tri-potent graph of a commutative ring R forms a 3-partite graph, discuss its planarity, and determine its independence domination number.
O. V. Lyubimtsev , A. A. Tuganbaev | International Journal of Algebra and Computation
Dario Spirito | Rendiconti del Circolo Matematico di Palermo Series 2
Sanjiv Subba , Tikaram Subedi | Annals of the Alexandru Ioan Cuza University - Mathematics
This article introduces the notion of an NJ-reflexive ring and demonstrates that it is distinct from the concept of a reflexive ring. The class of NJ-reflexive rings contains the class 
 This article introduces the notion of an NJ-reflexive ring and demonstrates that it is distinct from the concept of a reflexive ring. The class of NJ-reflexive rings contains the class of semicommutative rings, the class of left (right) quasi-duo rings, and the class of J-clean rings but is strictly larger than these classes. Additionally, the article investigates a sufficient condition for NJ-reflexive rings to be left (right) quasi-duo, as well as some conditions for NJ-reflexive rings to be reduced. It also explores extensions of NJreflexive rings and notes that the NJ-reflexive property may not carry over to polynomial extensions.
Chien-Hua Chen | Research in the Mathematical Sciences
Abstract Let R be an associative ring not necessarily with unity. We say that R is a semi-direct sum of rings S and I , if R = S + 
 Abstract Let R be an associative ring not necessarily with unity. We say that R is a semi-direct sum of rings S and I , if R = S + I , where S is a subring of a ring R , I is an ideal of R and S ∩ I = {0}. The aim of this paper is to investigate certain algebraic properties of semidirect sums of associative rings with applications to amalgamated rings. We generalize several results from the literature to associative rings without unity. In particular we show that the class of semi-direct sums of rings is equal to the class of amalgamated rings, we provide a description of the Jacobson radical of semi-direct sums and we offer a characterization of semi-direct sums that are left Steinitz rings.
Abstract For a valuation ring $V$, a smooth $V$-algebra $A$, and a reductive $V$-group scheme $G$ satisfying a certain natural isotropicity condition, we prove that every Nisnevich $G$-torsor on $\mathbb{A}^{N}_{A}$ 
 Abstract For a valuation ring $V$, a smooth $V$-algebra $A$, and a reductive $V$-group scheme $G$ satisfying a certain natural isotropicity condition, we prove that every Nisnevich $G$-torsor on $\mathbb{A}^{N}_{A}$ descends to a $G$-torsor on $A$. As a corollary, we generalize Raghunathan’s theorem on torsors over affine spaces to a relative setting. We also extend several affine representability results of Asok, Hoyois, and Wendt from equi-characteristics to mixed characteristics. Our proof relies on previous work on the purity of reductive torsors over smooth relative curves and the Grothendieck–Serre conjecture for constant reductive group schemes.
The monoform concept is defined as a module in which every nonzero submodule is rational. The primary goal of this research is to study this class of modules in terms 
 The monoform concept is defined as a module in which every nonzero submodule is rational. The primary goal of this research is to study this class of modules in terms of pure property, named purely monoform modules. It constitutes an extension of the monoform modules; in fact, the monoform modules are properly included in the class of purely monoform modules. Many characteristics of a purely monoform module have been offered as analogues to those in monoform modules. A discussion of how this class of modules relates to other related modules is considered, like almost monoform, purely uniform, purely quasi-Dedekind and purely prime modules. Besides that, other characterizations of the purely monoform module have been given similar to those known and satisfied in the monoform modules.
Abstract Continuing our work on group-theoretic generalisations of the prime Ax–Katz Theorem, we give a lower bound on the p -adic divisibility of the cardinality of the set of simultaneous 
 Abstract Continuing our work on group-theoretic generalisations of the prime Ax–Katz Theorem, we give a lower bound on the p -adic divisibility of the cardinality of the set of simultaneous zeros $Z(f_1,f_2,\dots,f_r)$ of r maps $f_j\,{:}\,A\rightarrow B_j$ between arbitrary finite commutative groups A and $B_j$ in terms of the invariant factors of $A, B_1,B_2, \cdots,B_r$ and the functional degrees of the maps $f_1,f_2, \dots,f_r$ .