Gorenstein AC亏范畴*

作者定义了Gorenstein AC导出范畴 D^b_gac(R)并且和导出范畴作了一些比较.作者定义了Gorenstein AC奇点范畴 D^b_gacsg(R),在这个范畴中具有有限Gorenstein AC- 投射维数的模都是零对象.同时, 作者给出了由Gorenstein AC- 投射模构成的稳定范畴到奇点范畴的三角嵌入 F : GAC → D^b_sg(R) .通过作函子 F 的商引入Gorenstein AC亏范畴 D^b_gacd(R),并且给出三角等价 D^b_gacd(R) = D^b_gacsg(R)     

Gorenstein正则环、奇点范畴和Ding模

本文证明了任意环的整体Ding投射维数和整体Ding内射维数一致,研究了奇点范畴和相对于Ding模的稳定范畴间的关系,并刻画了Gorenstein (正则)环以及环的整体维数的有限性.     

正合范畴的整体Gorenstein维数

设A是有足够多投射对象和足够多内射对象的正合范畴.本文研究了A的整体Gorenstein维数和A中的Gorenstein导出函子.利用同调的方法,证明了:如果A有可数直和与可数直积,那么sup{GpdM|M∈A}=sup{GidM|M∈A};对A中的对象M, N,若Gp M <∞, GidN <∞,则对任意的i≥0, Ext_GPⁱ(M, N)≌Ext_GIⁱ(M, N).     

正交类和相对Gorenstein模

在这篇论文中,我们研究了$\mathcal{A}$-Gorenstein投射模类和$\mathcal{A}$的左正交模类之间的关系,以及$\mathcal{A}$-Gorenstein内射模类和A的右正交模类之间的关系.我们得到了$\mathcal{A}$-Gorenstein投射模和$\mathcal{A}$-Gorenstein内射模的一些函子刻画.以完备对偶对为工具,我们讨论了$\mathcal{A}$-Gorenstein投射模和$\mathcal{B}$-Gorenstein平坦模之间的关系,并推广了一些已知结论.     

Gorenstein范畴上的一个问题

设■是阿贝尔范畴,■是■的子范畴.Sather-Wagstaff, Sharif和White引入了Gorenstein子范畴的概念,记为■.我们用■(相应地,■)代表纯投射R-模类(相应地,投射R-模类).本文给出了一类满足条件"■"的环,由此给出了当■是■的子范畴时,■是否包含在■中的一个否定回答.进一步,刻画了包含关系■和■何时成立.     

三角矩阵代数上奇点范畴和Gorenstein亏范畴的2-粘合

设■是三角矩阵代数,其中A和B是Artin代数,_AM_B是A-B-双模.本文研究了T上奇点范畴和Gorenstein亏范畴的2-粘合结构.在恰当的假设下,我们给出了T上奇点范畴和Gorenstein亏范畴的2-粘合存在的充分必要条件.     

奇点模型范畴的Quillen等价

令R是左Gorenstein环.我们构造了奇点反导出模型范畴和奇点余导出模型范畴(见文[Models for singularity categories,Adv Math.,2014,254:187-232])之间的Quillen等价.作为应用,给出了投射,内射模的正合复形的同伦范畴之间的一个具体的等价■.     

相对于半对偶化模的Gorenstein同调维数与Auslander范畴

设$R$是一个局部noether环. 我们在本文中研究了相对于半对偶化模$C$的Gorenstein投射, 内射与平坦模. 给出了$C$-Gorenstein同调维数与$\hat{R}$的Auslander范畴之间的关系.     

对偶扩张代数的shod子范畴与反变有限子范畴

设A是一个有限维代数,R是A的对偶扩张代数。本文研究代数R的shod子范畴,A-模范畴D的倾斜对象与R-模范畴D的倾斜对象之间的关系以及R的反变有限的子范畴。     

Locale范畴的反射子范畴

本文研究ｌｏｃａｌｅ范畴的反射子范畴，给出反射子范畴的刻划定理，从一般的ｌｏｃａｌｅ出发，完全构造性地给出了ｌｏｃａｌｅ的正则反射、完全正则反射和零维反射的构造．     

Homological Dimensions Relative to Special Subcategories

Let A be an abelian category,(L) an additive,full and self-orthogonal subcategory of A closed under direct summands,rG((L)) the right Gorenstein subcategory of A relative to (L),and ⊥(L) the left orthogonal class of (L).For an object A in A,we prove that if A is in the right 1-orthogonal class of rG((L)),then the (L)-projective and rG((L))-projective dimensions of A are identical;if the rG((L))-projective dimension of A is finite,then the rG((L))-projective and ⊥(L)-projective dimensions of A are identical.We also prove that the supremum of the (L)-projective dimensions of objects with finite (L)-projective dimension and that of the rG((L))-projective dimensions of objects with finite rG((L))-projective dimension coincide.Then we apply these results to the category of modules.     

Relative Regular Objects in Categories

We define the concept of a regular object with respect to another object in an arbitrary category. We present basic properties of regular objects and we study this concept in the special cases of abelian categories and locally finitely generated Grothendieck categories. Applications are given for categories of comodules over a coalgebra and for categories of graded modules, and a link to the theory of generalized inverses of matrices is presented. Some of the techniques we use are new, since dealing with arbitrary categories allows us to pass to the dual category.      

Gorenstein categories and Tate cohomology on projective schemes

We study Gorenstein categories. We show that such a category has Tate cohomological functors and Avramov–Martsinkovsky exact sequences connecting the Gorenstein relative, the absolute and the Tate cohomological functors. We show that such a category has what Hovey calls an injective model structure and also a projective model structure in case the category has enough projectives. As examples we show that if X is a locally Gorenstein projective scheme then the category ??????(X) of quasi‐coherent sheaves on X is such a category and so has these features. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Recollements of Singularity Categories and Monomorphism Categories

We generalize results on existence of recollement situations of singularity categories of lower triangular Gorenstein algebras and stable monomorphism categories of Cohen–Macaulay modules.     

Gorenstein Modules and Auslander Categories

In this article, some new characterizations of Gorenstein projective, injective, and flat modules over commutative noetherian local rings are given.     

On Stability of Gorenstein Categories

We show that an iteration of the procedure used to define the Gorenstein projective modules over a ring R yields exactly the Gorenstein projective modules. Specifically, given an exact sequence of Gorenstein projective left R-modules G = … → G ₁ → G ₀ → G ⁰ → G ¹ → … such that the complex Hom _R (G, H) is exact for each projective left R-module H, the module Im(G ₀ → G ⁰) is Gorenstein projective. We also get similar results for Gorenstein flat left R-modules when R is a right coherent ring. As applications, we obtain the corresponding results for Gorenstein complexes.     

Gorenstein flatness and injectivity over Gorenstein rings

Let R be a Gorenstein ring.We prove that if I is an ideal of R such that R/I is a semi-simple ring,then the Gorenstein flat dimension of R/I as a right R-module and the Gorenstein injective dimension of R/I as a left R-module are identical.In addition,we prove that if R→S is a homomorphism of rings and SE is an injective cogenerator for the category of left S-modules,then the Gorenstein flat dimension of S as a right R-module and the Gorenstein injective dimension of E as a left R-module are identical.We also give some applications of these results.