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AbstractA ring R with center C is said to be centrally essential if the module RC is an essential extension of the module CC . In this paper, we study properties of ideals of centrally essential rings, centrally essential quaternion algebras, and group rings of Hamiltonian groups. [ABSTRACT FROM AUTHOR]

Let Δ be an (abstract) simplicial complex on n vertices. One can define the Artinian monomial algebra A (Δ) = k [ x 1 , ... , x n ] / 〈 x 1 2 , ... , x n 2 , I Δ 〉 , where k is a field of characteristic 0 and I Δ is the Stanley-Reisner ideal associated to Δ. In this paper, we aim to characterize the Weak Lefschetz Property (WLP) of A (Δ) in terms of the simplicial complex Δ. We are able to completely analyze when the WLP holds in degree 1, complementing work by Migliore, Nagel and Schenck on the WLP for quotients by quadratic monomials. We give a complete characterization of all 2-dimensional pseudomanifolds Δ such that A (Δ) satisfies the WLP. We also construct Artinian Gorenstein algebras that fail the WLP by combining our results and the standard technique of Nagata idealization. [ABSTRACT FROM AUTHOR]

Let R be a commutative ring with identity and R ′ be the integral closure of R. In this paper, we show that if R is an affine algebra over a field K, then every regular ideal of R ′ is finitely generated, i.e., R ′ is an r-Noetherian ring. We also study when the integral closure of an affine algebra is Noetherian. First we show that if R is a Krull ring such that R/P is a Noetherian domain for each minimal regular prime ideal P of R, then R is an r-Noetherian ring, which is a generalization of Nishimura's result. As an application of this result, we prove that if R is an r-Noetherian ring with reg-dim R ≤ 2 , then R ′ is an r-Noetherian ring. We finally construct a couple of r-Noetherian rings, e.g., an r-Noetherian ring R that is not Noetherian and reg-dim R = ∞ or reg-dim R = n ≤ dim R = n + m − 1 for arbitrary positive integers n, m. [ABSTRACT FROM AUTHOR]

The Nagata ring R(X) and the Serre’s conjecture ring R⟨X⟩ are two localizations of the polynomial ring R[X] at the polynomials of unit content and at the monic polynomials, respectively. In this paper, we contribute to the study of Prüfer conditions in R(X) and R⟨X⟩. In particular, we solve the four open questions posed by Glaz and Schwarz in Section 8 of their survey paper [38] related to the transfer of Prüfer conditions to these two constructions. [ABSTRACT FROM AUTHOR]

By means of the maximal left ring of quotients, this paper proves that every n-Lie m-derivation on a triangular ring can be resolved into a sum of an extremal n-derivation and an n-additive central mapping. As applications, n-Lie m-derivations on some classical triangular rings are characterized. [ABSTRACT FROM AUTHOR]

In this paper, we give a necessary and sufficient condition for the Cohen-Macaulayness of the associated graded ring of a simplicial affine semigroup using Gröbner basis. We generalize the concept of homogeneous numerical semigroup for the simplicial affine semigroup and show that the Betti numbers of the corresponding semigroup ring matches with the Betti numbers of the associated graded ring. We also discuss nice extensions for simplicial affine semigroups, a concept which is motivated by nice extensions of numerical semigroups. [ABSTRACT FROM AUTHOR]

We present a proof that all straight domains are locally divided—thereby answering two open problems posed by Dobbs and Picavet, which appeared in the survey "Open Problems in Commutative Ring Theory" written by Cahen, Fontana, Frisch, and Glaz. In fact, we are able to prove a stronger result: a prime ideal of a domain is straight if and only if it is locally divided. [ABSTRACT FROM AUTHOR]

The famous Kurosh Problem for division rings asks whether a finitely generated algebraic division ring is centrally finite. This longstanding problem posed in 1941 by Kurosh remains without answer up to now. In this paper, we study some questions related to this problem for some classes of division rings. [ABSTRACT FROM AUTHOR]

Mutation of τ-tilting modules is a basic operation to construct a new support τ-tilting module from a given one by replacing a direct summand. The aim of this paper is to give a positive answer to the question posed in [2, Question 2.31] about mutation of τ-tilting modules. [ABSTRACT FROM AUTHOR]

A quasi-order on a set S is a binary, reflexive and transitive relation on S. In [3], Fakhruddin introduced the notion of (totally) quasi-ordered fields and showed that each such field is either an ordered field or else a valued field. Hence, quasi-ordered fields are very well suited to treat ordered and valued fields simultaneously. The aim of the present paper is to prove that an analogous dichotomy holds for commutative rings with 1 as well. [ABSTRACT FROM AUTHOR]

Let R be an associative ring with unity 1 and let a,b,c∈R. In this paper, several characterizations for hybrid (b,c)-inverses of a are given. Also, the hybrid (b,c)-inverse of a is characterized by the group inverse of ab, under certain hypothesis. In particular, existence criteria for the the inverse along an element are obtained. Finally, we get the double commutant property and the reverse order law of annihilator (b,c)-inverses. [ABSTRACT FROM AUTHOR]

With the present note the authors intend to correct a mistake in the paper Semiring and semimodule issues in MV-algebras, Communications in Algebra 41:3 (2013), 1017-1048, by the same authors. [ABSTRACT FROM AUTHOR]

A semigroup is called a Hua semigroup if any mapping h : S → S satisfying (∀ a , b ∈ S) h (a b) = h (a) h (b) or h (b) h (a) is either a homomorphism or an anti-homomorphism. We use this name for such a semigroup since it is relevant to a well-known result in ring theory, which is established by L. K. Hua in 1949. C. M. Reis and H. J. Shyr first translated Hua's result from rings to semigroups in 1977. In this paper, elementary characterizations, a hierarchy and closure properties of the class of Hua semigroups and its four subclasses are given. We show that every cancellative semigroup is a Hua semigroup, which generalizes Reis and Shyr's result. [ABSTRACT FROM AUTHOR]

In this paper, we give a necessary and sufficient condition for a graded algebra to be a McCoy ring. We then classify all McCoy rings of finite dimensional path algebras and truncated algebras over field K. This leads a new way of constructing McCoy rings. [ABSTRACT FROM AUTHOR]

In this paper, we prove that a ring R is left coherent if and only if the class 풜bs of absolutely pure left R-modules is a covering class. [ABSTRACT FROM AUTHOR]

Let (R,픪) be a Cohen-Macaulay local ring of positive dimension d and infinite residue field. Let I be an 픪-primary ideal and J a minimal reduction of I. In this paper, we show that . This answer to a question that made by Rossi and Swanson in [15, Question 4.6]. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the ring of Colombeau full generalized quaternion, and we study its algebraic and topological properties. We prove that the ring of Colombeau full generalized quaternion is Gelfand, normal, duo and some related properties. Moreover, we study the essential ideals of this ring. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the question of when the determinantal ring R over a field k is an almost Gorenstein local/graded ring in the sense of [14]. As a consequence of the main result, we see that if R is a non-Gorenstein almost Gorenstein local/graded ring, then the ring R has a minimal multiplicity. [ABSTRACT FROM AUTHOR]

In this paper, we study the graded Thierrin radical and the classical Thierrin radical of a graded ring, which is the direct sum of a family of its additive subgroups indexed by a nonempty set, under the assumption that the product of homogeneous elements is again homogeneous. There are two versions of this graded radical, the graded Thierrin and the large graded Thierrin radical. We establish several characterizations of the graded Thierrin radical and prove that the largest homogeneous ideal contained in the classical Thierrin radical of a graded ring coincides with the large graded Thierrin radical of that ring. [ABSTRACT FROM AUTHOR]

The aim of this paper is twofold. Firstly, to give short proofs of the celebrated results of Rudd (1970), De Marco (1972), Brookshear (1977), Neville (1990), and Vechtomov (1996) with the help of some well-known results in ring theory. Secondly, to establish new algebraic characterizations for when C(X) is von Neumann regular, semihereditary, or a Bézout ring. The notions of the greatest common divisor and least common multiple in the ring C(X) are studied. Finally, the space X, for which every idempotent of the classical quotient ring of C(X) is actually an element of C(X) itself, is completely determined. [ABSTRACT FROM AUTHOR]

In the paper by Furuya and Niitsuma [Furuya, M., Niitsuma, H. (2002a). On rn-adic higher differentials and regularities of Noetherian complete local rings. J. Math. Kyoto Univ. 42(1):33-40], we gave a regularity criterion of complete Noetherian local rings in terms of the concept of m-adic higher differentials with some assumptions of separability on the residue fields of the local rings. The aim of this paper is to try to weaken "the separability assumptions" in a premise of the theorems in Furuya and Niitsuma (2002a). [ABSTRACT FROM AUTHOR]

In this paper we study higher derivations of prime and semiprime rings satisfying linear relations. We extend several results known for algebraic derivations, and we prove some other results. [ABSTRACT FROM AUTHOR]

In this paper, we extend the recent work of C. Faith in which it is proved, using results of R.C. Shock that over a commutative ring R, the associated primes of the polynomial ring R[x] (viewed as a module over itself) are all extended; that is, every p ∈ Ass(R[x]) may be expressed as p = p[sub 0][x], where p[sub 0] = p ∩ R ∈ Ass(R). This result was originally proved in 1974 by Brewer and Heinzer using localization theory (see), but our work in this paper more closely parallels that of Faith. We will show that the result still holds in the more general setting of a polynomial module M[x] over a skew polynomial ring R[x; σ], with possibly noncommutative base ring R, provided a natural σ-compatibility assumption on M[sub R] (as defined in Sec. 2 below) is fulfilled. Moreover, if we assume that σ ∈ Aut(R), we can make the set of Laurent polynomials M[x, x[sup -1]] into a module over Rfx; σ] and R[x, x[sup -1]; σ], and the main result still holds in these cases as well (for σ-compatible M[sub R]). Finally, we also show that the result does not extend to the case of skew formal power series rings and skew Laurent series rings in general, although it does if R is a left perfect ring. [ABSTRACT FROM AUTHOR]

The notion of π-regularity is a generalization of von Neumann regularity. In this paper we begin our investigation of πregular and strongly π-regular semigroup graded rings. We first consider the π-regularity of those semigroup graded rings whose prime ideals and radicals were characterized by authors such as Bell, Stalder and Teply in recent papers. The classes of semigroups underlying these semigroup graded rings include, as examples, regular bands, Clifford semigroups, commutative power stationary semigroups and more generally commutative semigroups for which every element has a power lying in a subgroup. We then extend our study to Munn rings and inverse semigroup rings. In the case of strong regular band graded rings we characterize π-regularity of the ring in terms of π-regularity of its homogeneous components. For rings graded strongly by Clifford semigroups as well as for Munn rings and inverse semigroup rings, the study of π-regularity is reduced to the case of group rings. [ABSTRACT FROM AUTHOR]

The paper considers finite rank torsion-free rings, i.e, subrings of finite-dimensional rational algebras. The main result of the paper is the characterization of finite rank torsion-free rings with finite automorphism groups. Nontrivial examples of rings R with AutR finite have been constructed. [ABSTRACT FROM AUTHOR]

The rate of a graded moduleMover a standard graded algebraR,rateR(M), is a measure of the growth of the shifts in the minimal graded free resolution ofM. In this paper, we study the rate of Veronese modules ofM. More precisely, it is shown thatfor allc≥1. This extends a result of Aramova et al. [2] As a consequence of this, ifMis generated in degree zero, then, for allc≥max{rateR(M),Rate(R)}. Also, it is shown that, for all integerss,c≥1. In particular case, we give a simple proof to a result of Backelin. [ABSTRACT FROM PUBLISHER]

In this paper we provide conditions under which automorphism-coinvariant modules over a right perfect ring are quasi-projective. [ABSTRACT FROM PUBLISHER]

In the first part of this paper, we point out some errors in Communications in Algebra, 45(11) (2017), 4631–4645 and then we give a correct version of the errant results. The second part presents our contribution in the study of two-sided α-derivations satisfying certain identities over near-rings. [ABSTRACT FROM AUTHOR]

Let R be a noncommutative prime ring, I a nonzero left ideal of R, L a non-central Lie ideal of R, U the left Utumi quotient ring of R and C = Z (U) the extended centroid of R. Let G be a generalized derivation of R and g be a derivation of R and m , n , r , k fixed positive integers. In the present paper, we describe the structure of R and all possible forms of G and g in the following cases: [ G (x m) x n + x n g (x m) , x r ] k = 0 , for all x ∈ I ; char (R) ≠ 2 and [ G (x m) x n + x n g (x m) , x r ] k = 0 , for all x ∈ L. [ABSTRACT FROM AUTHOR]

LetRbe a ring with unity. The inclusion ideal graph of a ringR, denoted by In(R), is a graph whose vertices are all nontrivial left ideals ofRand two distinct left idealsIandJare adjacent if and only ifI ⊂ JorJ ⊂ I. In this paper, we show that In(R) is not connected if and only ifR ≅ M2(D) orD1 × D2, for some division rings,D,D1andD2. Moreover, we prove that if In(R) is connected, then diam(In(R)) ≤3. It is shown that if In(R) is a tree, then In(R) is a caterpillar with diam(In(R)) ≤3. Also, we prove that the girth of In(R) belongs to the set {3, 6, ∞}. Finally, we determine the clique number and the chromatic number of the inclusion ideal graph for some classes of rings. [ABSTRACT FROM AUTHOR]

In the theory of Schur rings, it is known that every Schur ring over a cyclic p-group is Schurian. Recently, Spiga and Wang showed that every p-Schur ring over an elementary abelian p-group of rank 3 is Schurian. In this paper, we prove that every p-Schur ring over an abelian group of orderp3is Schurian. [ABSTRACT FROM AUTHOR]

In this paper, we construct derived equivalences between two subrings of relevant Φ-Yoneda rings from an arbitrary short exact sequence in an abelian category. As a consequence, any short exact sequence in an abelian category gives rise to a derived equivalence between two subrings of endomorphism rings. [ABSTRACT FROM PUBLISHER]

In this paper, we give a new simple algebraic proof of the involutivity of the characteristic variety after Gabber, which is one of the most important results ofD-module theory. [ABSTRACT FROM AUTHOR]

This is a slight extension of an expository paper I wrote a while ago as a supplement to my joint work with Declan Quinn on Burnside's theorem for Hopf algebras. It was never published, but may still be of interest to students and beginning researchers. LetKbe a field, and letAbe an algebra overK. Then the tensor productA ⊗ A = A ⊗KAis also aK-algebra, and it is quite possible that there exists an algebra homomorphism Δ:A → A ⊗ A. Such a map Δ is called a comultiplication, and the seemingly innocuous assumption on its existence providesAwith a good deal of additional structure. For example, using Δ, one can define a tensor product on the collection ofA-modules, and whenAand Δ satisfy some rather mild axioms, thenAis called a bialgebra. Classical examples of bialgebras include group ringsK[G] and Lie algebra enveloping ringsU(L). Indeed, most of this paper is devoted to a relatively self-contained study of some elementary bialgebra properties of these examples. Furthermore, Δ determines a convolution product on HomK(A,A), and this leads quite naturally to the definition of a Hopf algebra. [ABSTRACT FROM AUTHOR]

Let R be a semiprime ring and I a nonzero ideal of R. A map F:R→R is called a multiplicative generalized derivation if there exists a map d:R→R such that F(xy) = F(x)y+xd(y), for all x,y∈R. In the present paper, we shall prove that R contains a nonzero central ideal if any one of the following holds: i) ii) iii) F is SCP on I, iv) F(u)∘F(v) = u∘v, for all u,v∈I. [ABSTRACT FROM AUTHOR]

A Poisson algebra is a Lie algebra endowed with a commutative associative product in such a way that the Lie and associative products are compatible via a Leibniz rule. If we part from a Lie color algebra, instead of a Lie algebra, a graded-commutative associative product and a graded-version Leibniz rule we get a so-called Poisson color algebra (of degree zero). This concept can be extended to any degree, so as to obtain the class of Poisson color algebras of arbitrary degree. This class turns out to be a wide class of algebras containing the ones of Lie color algebras (and so Lie superalgebras and Lie algebras), Poisson algebras, graded Poisson algebras, z-Poisson algebras, Gerstenhaber algebras, and Schouten algebras among other classes of algebras. The present paper is devoted to the study of structure of Poisson color algebras of degree g0, where g0 is some element of the grading group G such that g0 = 0 or 4g0≠0, and with restrictions neither on the dimension nor the base field, by stating a second Wedderburn-type theorem for this class of algebras. [ABSTRACT FROM AUTHOR]

We study the problem of lifting of polynomial symplectomorphisms in characteristic zero to automorphisms of the Weyl algebra by means of approximation by tame automorphisms. In 1983, Anick proved the fundamental result on approximation of polynomial automorphisms. We obtain similar approximation theorems for symplectomorphisms and Weyl algebra authomorphisms. We then formulate the lifting problem. More precisely, we prove the possibility of lifting of a symplectomorphism to an automorphism of the power series completion of the Weyl algebra of the corresponding rank. The lifting problem has its origins in the context of deformation quantization of the affine space and is closely related to several major open problems in algebraic geometry and ring theory. This paper is a continuation of the study [19]. [ABSTRACT FROM AUTHOR]

Let (R,픪) be a Noetherian local ring. In this paper, we give a new characterization for the universal catenaricity of R and the Cohen-Macaulayness of all its formal fibers, and we study the cofiniteness and annihilators of local cohomology modules. [ABSTRACT FROM AUTHOR]

In this paper, we study third power associative, antiflexible rings satisfying the identity (a,b,ac) = a(a,b,c). We prove that third power associative, antiflexible rings satisfying the identity (a,b,ac) = a(a,b,c) with characteristic ≠2,3 are associative of degree 5. As a consequence of this result, we prove that a third power associative semiprime antiflexible ring satisfying the identity (a,b,ac) = a(a,b,c) is associative. [ABSTRACT FROM AUTHOR]

In this paper, we introduce von Neumann regular modules and give many characterizations of von Neumann regular modules. Further, we investigate the relations between von Neumann regular modules and other classical modules. Finally, we characterize Noetherian von Neumann regular modules. [ABSTRACT FROM AUTHOR]

In 1971, Koehler [11] proved a structure theorem for quasi-projective modules over right perfect rings by using results of Wu-Jans [22]. Later Mohamed-Singh [17] studied discrete modules over right perfect rings and gave decomposition theorems for these modules. Moreover, Oshiro [18] deeply studied (quasi-)discrete modules over general rings. In this paper, we consider that decomposition theorems for H-supplemented modules with the condition (D2) or (D3) over right perfect rings. [ABSTRACT FROM AUTHOR]

The notion of a U-module was introduced and thoroughly investigated in [11] as a strict and simultaneous generalization of quasi-continuous, square-free and automorphism-invariant modules. In this paper a right R-module M is called a U*-module if every submodule of M is a U-module, and a ring R is called a right U*-ring if RR is a U*-module. We show that M is a U*-module iff whenever A and B are submodules of M with A≅B and A∩B = 0, A⊕B is a semisimple summand of M; equivalently M = X⊕Y, where X is semisimple, Y is square-free, and X & Y are orthogonal. In particular, a ring R is a right U*-ring iff R is a direct product of a square-full semisimple artinian ring and a right square-free ring. Moreover, right U*-rings are shown to be directly-finite, and if the ring is also an exchange ring then it satisfies the substitution property, has stable-range 1, and hence is stably-finite. These results are non-trivial extensions of similar ones on rings all of whose right ideals are either quasi-continuous or auto-invariant. [ABSTRACT FROM AUTHOR]

Let V be a valuation domain and V[[X]] be the power series ring over V. In this paper, we show that if V[[X]] is a locally finite intersection of valuation domains, then V is an SFT domain and hence a discrete valuation domain. As a consequence, it is shown that the power series ring V[[X]] is a Krull domain if and only if V[[X]] is a generalized Krull domain if and only if V[[X]] is an integral domain of Krull type (or equivalently, a PvMD of finite t-character) if and only if V is a discrete valuation domain with Krull dimension at most one. [ABSTRACT FROM AUTHOR]

In this paper we shall prove the following result, which is a generalization of the Melkersson's main result proved in [16]. Let (R, 𝔪) be a Noetherian local ring such thatis integral overR. LetIbe a proper ideal ofRandAbe an ArtinianR-module. ThenAisI-cofinite if and only if Rad(I + AnnR(A)) = 𝔪. Also, we present an example to show that this result does not hold for an arbitrary local Noetherian ring in general. As an application of this result we prove the following generalization of the Lichtenbaum-Hartshorne Vanishing Theorem (see [5, Theorem 8.2.1]). Let (R, 𝔪) be a Noetherian local ring such thatis integral overR. LetIan ideal ofRandMbe a nonzero finitely generatedR-module of dimensionn. Then the following conditions are equivalent: (i). (ii) There exists a prime ideal 𝔭 in AsshR(M) such that Rad(𝔭 +I) = 𝔪. [ABSTRACT FROM PUBLISHER]

Let R be a commutative ring with identity 1 ≠ 0 and T be the ring of all n × n upper triangular matrices over R. In this paper, we describe the zero divisor graphof T. Some basic graph theory properties ofare given, including determination of the girth and diameter. The structure ofis discussed, and bounds for the number of edges are given. In the case that R is a finite integral domain and n = 2, the structure ofis fully described and an explicit formula for the number of edges is given. [ABSTRACT FROM PUBLISHER]

Let A = A0 ⊕ A1 ⊕ A2 ⊕ ··· be a graded K-algebra such that A0 is a finite product of copies of the field K, A is generated in degrees 0 and 1, and dimKA1 < ∞. We study those graded algebras A with the property that A0, viewed as a graded A-module, has a graded projective resolution, ··· ↵ Pt ↵ ··· ↵ P1 ↵ P0 ↵ A0 0, such that each Pi can be generated in a single degree. The paper describes necessary and sufficient conditions for the Ext-algebra of A, ⊕n≥0 ExtnA(A0, A0), to be finitely generated. We also investigate classes of modules over such algebras and Veronese subrings of the Ext-algebra. [ABSTRACT FROM AUTHOR]

In this paper, the authors introduce the concept of integrally closed modules and characterize Dedekind modules and Dedekind domains. They also show that a given domain R is integrally closed if and only if a finitely generated torsion-free projective R -module is integrally closed. In addition, it is proved that any invertible submodule of a finitely generated projective module over a domain is finitely generated and projective. Also they give the equivalent conditions for Dedekind modules and Dedekind domains. [ABSTRACT FROM AUTHOR]

In this paper, we investigate integral domains in which each ideal is a w -ideal (i.e. the d - and w -operations are the same), called the DW -domains. In some sense this study is similar to that one given in Houston and Zafrullah (1988) [Houston, E., Zafrullah, M. (1988). Integral domains in which each t -ideal is divisorial. Michigan Math. J. 35:291–300.] for the TV -domains. We prove that a domain R is a DW -domain if and only if each maximal ideal of R is a w -ideal, and if R is a domain such that R M is a DW -ideal for each maximal ideal M of R , then so is R , and the equivalence holds when R is v -coherent. We describe the w -operation on pull–backs in order to provide original examples. [ABSTRACT FROM AUTHOR]

In this paper, we study the behavior of the couniform (or dual Goldie) dimension of a module under various polynomial extensions. For a ring automorphism s ? Aut( R ), we use the notion of a s-compatible module M R to obtain results on the couniform dimension of the polynomial modules M [ x ], M [ x -1 ], and M [ x , x -1 ] over suitable skew extension rings. [ABSTRACT FROM AUTHOR]

Given a family of commutative rings { R a } a? A , we investigate the family ??(? a? A R a ) of Artinian subrings of ? a? A R a . This paper deals also with the question of when a pair (? a? A R a , ? a? A T a ) is zero-dimensional, where {( R a , T a )} a? A is a family of zero-dimensional pairs. [ABSTRACT FROM AUTHOR]