∏-COHERENT DIMENSIONS AND∏-COHERENT RINGS

L Mao - Journal of the Korean Mathematical Society, 2007 - koreascience.kr
R is called a right ${\Pi}-coherent $ ring in case every finitely generated torsion less right R-
module is finitely presented. In this paper, we define a dimension for rings, called ${\Pi} …

[PDF][PDF] Relative projective dimensions

L DUAN, W LI - Bulletin of the Malaysian Mathematical Society, 2014 - kurims.kyoto-u.ac.jp
Abstract In (n, d)-ring and n-coherent ring theory, n-presented modules plays an important
role. In this paper, we firstly give some new characterizations of n-presented modules and n …

On divisible and torsionfree modules

L Mao, N Ding - Communications in Algebra®, 2008 - Taylor & Francis
A ring R is called left P-coherent in case each principal left ideal of R is finitely presented. A
left R-module M (resp. right R-module N) is called D-injective (resp. D-flat) if Ext1 (G, M)= 0 …

J-coherent rings

N Ding, Y Li, L Mao - Journal of Algebra and Its Applications, 2009 - World Scientific
Let R be a ring. Recall that a left R-module M is coherent if every finitely generated
submodule of M is finitely presented. R is a left coherent ring if the left R-module RR is …

On envelopes with the unique mapping property

N Ding - Communications in Algebra, 1996 - Taylor & Francis
We prove that (a) if R is a left coherent ring, then the weak global dimension w D (R)<= n
(n>= 2) if and only if every (n–2) th F–cosyzygy of a finitely presented right R–module has a …

FGT-injective dimensions of Π-coherent rings and almost excellent extension

Y Xiang - Proceedings-Mathematical Sciences, 2010 - Springer
We study, in this article, the FGT-injective dimensions of Π-coherent rings. If R is right Π-
coherent, and TI (resp. TF) stands for the class of FGT-injective (resp. FGT-flat) R-modules …

Weak global dimension of coherent rings

L Mao, N Ding - Communications in Algebra, 2007 - Taylor & Francis
In this article, we study the weak global dimension of coherent rings in terms of the left FP-
injective resolutions of modules. Let R be a left coherent ring and ℱ ℐ the class of all FP …

On n -Coherent Rings and ( n , d )-Rings

D Zhou - 2004 - Taylor & Francis
We introduce the concepts of (n, d)-injective and (n, d)-flat as generalizations of injective, flat
modules and homological dimensions, and use them to characterize right n-coherent rings …

[PDF][PDF] The Excellent Extensions of Rings and Copure Dimensions

B LU - Chinese Quarterly Journal of Mathematics, 2012 - sxjk.magtechjournal.com
Let R be a noetherian ring and S an excellent extension of R. cid (M) denotes the copure
injective dimension of M and cfd (M) denotes the copure flat dimension of M. We prove that if …

On n-coherent rings and (n, d)-injective modules

D Zhang, B Ouyang - Algebra Colloquium, 2015 - World Scientific
Let R be a ring, n, d be fixed non-negative integers, the class of (n, d)-injective left R-
modules, and the class of (n, d)-flat right R-modules. In this paper, we prove that if R is a left …