Noncommutative G-hereditary rings

Author(s):  
Yunxia Li ◽  
Jian Wang ◽  
Yuxian Geng ◽  
Jiangsheng Hu

In this paper, we introduce and study left (right) [Formula: see text]-hereditary rings over any associative ring, and these rings are exactly [Formula: see text]-hereditary rings defined by Mahdou and Tamekkante provided that [Formula: see text] is a commutative ring. As applications, we give a partial answer to the question posed by Bazzoni, Cortés-Izurdiaga and Estrada, and characterize when the character module of a Gorenstein injective left [Formula: see text]-module is Gorenstein flat provided that [Formula: see text] is a left [Formula: see text]-hereditary ring. In addition, some new characterizations of left hereditary rings are given.

2016 ◽  
Vol 15 (08) ◽  
pp. 1650156
Author(s):  
Bin Yu

In this paper, we investigate the rings over which a module is Gorenstein flat if and only if it is Gorenstein projective. Some examples of such rings are given. We show that over such rings the class of Gorenstein projective modules is covering. We also characterize the rings over which the class of Gorenstein projective modules is preenveloping. As a conclusion, we obtain that a commutative ring is artinian if and only if every module has a Gorenstein projective preenvelope. The existence of pure injective Gorenstein injective preenvelopes over certain rings is also shown.


2018 ◽  
Vol 17 (01) ◽  
pp. 1850014 ◽  
Author(s):  
Jian Wang ◽  
Yunxia Li ◽  
Jiangsheng Hu

In this paper, we introduce and study left (right) [Formula: see text]-semihereditary rings over any associative ring, and these rings are exactly [Formula: see text]-semihereditary rings defined by Mahdou and Tamekkante provided that [Formula: see text] is a commutative ring. Some new characterizations of left [Formula: see text]-semihereditary rings are given. Applications go in three directions. The first is to give a sufficient condition when a finitely presented right [Formula: see text]-module is Gorenstein flat if and only if it is Gorenstein projective provided that [Formula: see text] is left coherent. The second is to investigate the relationships between Gorenstein flat modules and direct limits of finitely presented Gorenstein projective modules. The third is to obtain some new characterizations of semihereditary rings, [Formula: see text]-[Formula: see text] rings and [Formula: see text] rings.


Author(s):  
Rasul Mohammadi ◽  
Ahmad Moussavi ◽  
Masoome Zahiri

Let [Formula: see text] be an associative ring with identity. A right [Formula: see text]-module [Formula: see text] is said to have Property ([Formula: see text]), if each finitely generated ideal [Formula: see text] has a nonzero annihilator in [Formula: see text]. Evans [Zero divisors in Noetherian-like rings, Trans. Amer. Math. Soc. 155(2) (1971) 505–512.] proved that, over a commutative ring, zero-divisor modules have Property ([Formula: see text]). We study and construct various classes of modules with Property ([Formula: see text]). Following Anderson and Chun [McCoy modules and related modules over commutative rings, Comm. Algebra 45(6) (2017) 2593–2601.], we introduce [Formula: see text]-dual McCoy modules and show that, for every strictly totally ordered monoid [Formula: see text], faithful symmetric modules are [Formula: see text]-dual McCoy. We then use this notion to give a characterization for modules with Property ([Formula: see text]). For a faithful symmetric right [Formula: see text]-module [Formula: see text] and a strictly totally ordered monoid [Formula: see text], it is proved that the right [Formula: see text]-module [Formula: see text] is primal if and only if [Formula: see text] is primal with Property ([Formula: see text]).


2003 ◽  
Vol 31 (2) ◽  
pp. 991-1005 ◽  
Author(s):  
Leila Khatami ◽  
Siamak Yassemi

Author(s):  
T. Cheatham ◽  
E. Enochs

AbstractAn associative ring R with identity is said to be c-commutative for c ∈ R if a, b ∈ R and ab = c implies ba = c. Taft has shown that if R is c-commutative where c is a central nonzero divisor]can be omitted. We show that in R[x] is h(x)-commutative for any h(x) ∈ R [x] then so is R with any finite number of (commuting) indeterminates adjoined. Examples adjoined. Examples are given to show that R [[x]] need not be c-commutative even if R[x] is, Finally, examples are given to answer Taft's question for the special case of a zero-commutative ring.


2020 ◽  
Vol 27 (03) ◽  
pp. 575-586
Author(s):  
Sergio Estrada ◽  
Alina Iacob ◽  
Holly Zolt

For a given class of modules [Formula: see text], let [Formula: see text] be the class of exact complexes having all cycles in [Formula: see text], and dw([Formula: see text]) the class of complexes with all components in [Formula: see text]. Denote by [Formula: see text][Formula: see text] the class of Gorenstein injective R-modules. We prove that the following are equivalent over any ring R: every exact complex of injective modules is totally acyclic; every exact complex of Gorenstein injective modules is in [Formula: see text]; every complex in dw([Formula: see text][Formula: see text]) is dg-Gorenstein injective. The analogous result for complexes of flat and Gorenstein flat modules also holds over arbitrary rings. If the ring is n-perfect for some integer n ≥ 0, the three equivalent statements for flat and Gorenstein flat modules are equivalent with their counterparts for projective and projectively coresolved Gorenstein flat modules. We also prove the following characterization of Gorenstein rings. Let R be a commutative coherent ring; then the following are equivalent: (1) every exact complex of FP-injective modules has all its cycles Ding injective modules; (2) every exact complex of flat modules is F-totally acyclic, and every R-module M such that M+ is Gorenstein flat is Ding injective; (3) every exact complex of injectives has all its cycles Ding injective modules and every R-module M such that M+ is Gorenstein flat is Ding injective. If R has finite Krull dimension, statements (1)–(3) are equivalent to (4) R is a Gorenstein ring (in the sense of Iwanaga).


2009 ◽  
Vol 87 (3) ◽  
pp. 395-407 ◽  
Author(s):  
ZHONGKUI LIU ◽  
XIAOYAN YANG

AbstractIn basic homological algebra, projective, injective and flat modules play an important and fundamental role. In this paper, we discuss some properties of Gorenstein projective, injective and flat modules and study some connections between Gorenstein injective and Gorenstein flat modules. We also investigate some connections between Gorenstein projective, injective and flat modules under change of rings.


2004 ◽  
Vol 32 (11) ◽  
pp. 4415-4432
Author(s):  
Javad Asadollahi ◽  
Shokrollah Salarian

2019 ◽  
Vol 57 (1) ◽  
pp. 55-83
Author(s):  
Edgar Enochs ◽  
J.R. García Rozas ◽  
Luis Oyonarte ◽  
Blas Torrecillas

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