scholarly journals Onn-flat modules andn-Von Neumann regular rings

Author(s):  
Najib Mahdou

We show that eachR-module isn-flat (resp., weaklyn-flat) if and only ifRis an(n,n−1)-ring (resp., a weakly(n,n−1)-ring). We also give a new characterization ofn-Von Neumann regular rings and a characterization of weakn-Von Neumann regular rings for (CH)-rings and for local rings. Finally, we show that in a class of principal rings and a class of local Gaussian rings, a weakn-Von Neumann regular ring is a (CH)-ring.

Author(s):  
Zoran Petrovic ◽  
Maja Roslavcev

Let R be a commutative von Neumann regular ring. We show that every finitely generated ideal I in the ring of polynomials R[X] has a strong Gr?bner basis. We prove this result using only the defining property of a von Neumann regular ring.


1985 ◽  
Vol 37 (6) ◽  
pp. 1134-1148
Author(s):  
David Handelman

In this paper, we are primarily concerned with the behaviour of the centre with respect to the completion process for von Neumann regular rings at the pseudo-metric topology induced by a pseudo-rank function.Let R be a (von Neumann) regular ring, and N a pseudo-rank function (all terms left undefined here may be found in [6]). Then N induces a pseudo-metric topology on R, and the completion of R at this pseudo-metric, , is a right and left self-injective regular ring. Let Z( ) denote the centre of whatever ring is in the brackets. We are interested in the map .If R is simple, Z(R) is a field, so is discrete in the topology; yet Goodearl has constructed an example with Z(R) = R and Z(R) = C [5, 2.10]. There is thus no hope of a general density result.


1974 ◽  
Vol 17 (2) ◽  
pp. 283-284 ◽  
Author(s):  
Kwangil Koh

Recently, in the Research Problems of Canadian Mathematical Bulletin, Vol. 14, No. 4, 1971, there appeared a problem which asks “Is a prime Von Neumann regular ring pimitive?” While we are not able to settle this question one way or the other, we prove that in a Von Neumann regular ring, there is a maximal annihilator right ideal if and only if there is a minimal right ideal.


Filomat ◽  
2012 ◽  
Vol 26 (2) ◽  
pp. 253-259
Author(s):  
Malakooti Rad ◽  
S.H. Ghalandarzadeh ◽  
S. Shirinkam

Let R be a commutative ring with identity and M be a unitary R-module. A torsion graph of M, denoted by ?(M), is a graph whose vertices are the non-zero torsion elements of M, and two distinct vertices x and y are adjacent if and only if [x : M][y : M]M = 0. In this paper, we investigate the relationship between the diameters of ?(M) and ?(R), and give some properties of minimal prime submodules of a multiplication R-module M over a von Neumann regular ring. In particular, we show that for a multiplication R-module M over a B?zout ring R the diameter of ?(M) and ?(R) is equal, where M , T(M). Also, we prove that, for a faithful multiplication R-module M with |M|?4,?(M) is a complete graph if and only if ?(R) is a complete graph.


2006 ◽  
Vol 13 (01) ◽  
pp. 163-172 ◽  
Author(s):  
Gary F. Birkenmeier ◽  
Dinh Van Huynh ◽  
Jin Yong Kim ◽  
Jae Keol Park

We extend various properties from a direct summand X of a module M, whose complement is semisimple, to its trace in M or to M itself. The case when MR = RR and the properties are injectivity or P-injectivity is fully described. As applications, we extend some known results for right HI-rings and give a new characterization of semisimple rings. We conclude this paper by giving some conditions that yield the self-injectivity of von Neumann regular rings.


2015 ◽  
Vol 58 (4) ◽  
pp. 741-756 ◽  
Author(s):  
Zenghui Gao

AbstractLet ε be an injectively resolving subcategory of left R-modules. A left R-module M (resp. right R-module N) is called ε-injective (resp. ε-flat) if Ext1R (G,M) = 0 (resp. TorR1 (N, G) = 0) for any G ∊ ε. Let ε be a covering subcategory. We prove that a left R-module M is E-injective if and only if M is a direct sum of an injective left R-module and a reduced E-injective left R-module. Suppose ℱ is a preenveloping subcategory of right R-modules such that ε+ ⊆ ℱ and ℱ+ ⊆ ε. It is shown that a finitely presented right R-module M is ε-flat if and only if M is a cokernel of an ℱ-preenvelope of a right R-module. In addition, we introduce and investigate the ε-injective and ε-flat dimensions of modules and rings. We also introduce ε-(semi)hereditary rings and ε-von Neumann regular rings and characterize them in terms of ε-injective and ε-flat modules.


1971 ◽  
Vol 4 (1) ◽  
pp. 57-62 ◽  
Author(s):  
K. M. Rangaswamy ◽  
N. Vanaja

It is shown that a von Neumann regular ring R is left seif-injective if and only if every finitely generated torsion-free left R-module is projective. It is further shown that a countable self-injective strongly regular ring is Artin semi-simple.


2013 ◽  
Vol 20 (02) ◽  
pp. 343-347 ◽  
Author(s):  
Liang Shen

Let R be a J-regular ring, i.e., R/J(R) is a von Neumann regular ring, where J(R) is the Jacobson radical of R. It is proved: (i) For every n ≥ 1, R is right n-injective if and only if every homomorphism from an n-generated small right ideal of R to RR can be extended to one from RR to RR. (ii) R is right FP-injective if and only if R is right (J,R)-FP-injective. Some known results are improved.


1969 ◽  
Vol 12 (4) ◽  
pp. 417-426 ◽  
Author(s):  
R.C. Courter

We prove in this paper that fifteen classes of rings coincide with the class of rings named in the title. One of them is the class of rings R such that X2 = X for each R-ideal X: we shall refer to rings with this property (and thus to the rings of the title) as fully idempotent rings. The simple rings and the (von Neumann) regular rings are fully idempotent. Indeed, every finitely generated right or left ideal of a regular ring is generated by an idempotent [l, p. 42], so that X2 = X holds for every one-sided ideal X.


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