We introduce and study the relative lett derive functor Torn（￡,￡1） category, which unifies several related left derived functors. Then we give some criteria for computing the -resolution dimensions of modules in t...We introduce and study the relative lett derive functor Torn（￡,￡1） category, which unifies several related left derived functors. Then we give some criteria for computing the -resolution dimensions of modules in terms of the properties of Torn（￡,￡1） . We also construct a complete and hereditary cotorsion pair relative to balanced pairs. Some known results are obtained as corollaries.展开更多
In this paper, we investigate Ding projective dimensions and Ding injective di- mensions of modules and rings. Let R be a ring with rDPD（R） = n 〈 ∞, and let YYl = {Mild（M） 〈 ∞}. We prove that （DP,W1） is a co...In this paper, we investigate Ding projective dimensions and Ding injective di- mensions of modules and rings. Let R be a ring with rDPD（R） = n 〈 ∞, and let YYl = {Mild（M） 〈 ∞}. We prove that （DP,W1） is a complete hereditary cotorsion pair such that a module M belongs to DD∩W1 if and only if M is projective, moreover, 1421 = （M[pd（M） 〈 ∞} = {MIfd（M） ≤ n} = {MIpd（M） ≤ n}. Then we introduce and inves- tigate Ding derived functor Dext^i（-, -）, and use it to characterize global Ding dimension. We show that if R is a Ding-Chen ring, or if R is a ring with rDPD（R） 〈≤ and rDID（R） 〈 ≤, then rDPD（R） 〈 n if and only if rDID（R） 〈 n if and only if Dext^n＋i（M,N） = 0 for all modules M and N and all integer i ≥ 1.展开更多
We study the homology of the dual de Rham complex as functors on the category of abelian groups.We give a description of homology of the dual de Rham complex up to degree 7 for free abelian groups and present a correc...We study the homology of the dual de Rham complex as functors on the category of abelian groups.We give a description of homology of the dual de Rham complex up to degree 7 for free abelian groups and present a corrected version of the proof of Jean’s computations of the zeroth homology group.展开更多
We consider the preservation property of the homomorphism and tensor product functors for quasi-isomorphisms and equivalences of complexes. Let X and Y be two classes of R-modules with Ext〉I（X,Y） = 0 for each objec...We consider the preservation property of the homomorphism and tensor product functors for quasi-isomorphisms and equivalences of complexes. Let X and Y be two classes of R-modules with Ext〉I（X,Y） = 0 for each object X ∈ X and each object Y ∈ Y. We show that if A,B ∈ C^（R） are X-complexes and U, V ∈ Cr（R） are Y-complexes, then U V Hom（A, U） Hom（A, Y）; A B Hom（B, U） Hom（A, U）. As an application, we give a sufficient condition for the Hom evaluation morphism being invertible.展开更多
基金Supported by NSFC(Grant Nos.11171142,11571164)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We introduce and study the relative lett derive functor Torn（￡,￡1） category, which unifies several related left derived functors. Then we give some criteria for computing the -resolution dimensions of modules in terms of the properties of Torn（￡,￡1） . We also construct a complete and hereditary cotorsion pair relative to balanced pairs. Some known results are obtained as corollaries.
基金Supported by the National Natural Science Foundation of China(11201424)the Zhejiang Natural Science Foundation of China(LY12A01026)
文摘In this paper, we investigate Ding projective dimensions and Ding injective di- mensions of modules and rings. Let R be a ring with rDPD（R） = n 〈 ∞, and let YYl = {Mild（M） 〈 ∞}. We prove that （DP,W1） is a complete hereditary cotorsion pair such that a module M belongs to DD∩W1 if and only if M is projective, moreover, 1421 = （M[pd（M） 〈 ∞} = {MIfd（M） ≤ n} = {MIpd（M） ≤ n}. Then we introduce and inves- tigate Ding derived functor Dext^i（-, -）, and use it to characterize global Ding dimension. We show that if R is a Ding-Chen ring, or if R is a ring with rDPD（R） 〈≤ and rDID（R） 〈 ≤, then rDPD（R） 〈 n if and only if rDID（R） 〈 n if and only if Dext^n＋i（M,N） = 0 for all modules M and N and all integer i ≥ 1.
基金supported by the grant of the Government of the Russian Federation for the state support of scientific research carried out under the supervision of leading scientistsagreement 14.W03.31.0030 dated 15.02.2018.1。
文摘We study the homology of the dual de Rham complex as functors on the category of abelian groups.We give a description of homology of the dual de Rham complex up to degree 7 for free abelian groups and present a corrected version of the proof of Jean’s computations of the zeroth homology group.
基金Supported by National Natural Science Foundation of China (Grant No. 10961021)Program of Science and Technique of Gansu Province (Grant No. 1010RJZA025)
文摘We consider the preservation property of the homomorphism and tensor product functors for quasi-isomorphisms and equivalences of complexes. Let X and Y be two classes of R-modules with Ext〉I（X,Y） = 0 for each object X ∈ X and each object Y ∈ Y. We show that if A,B ∈ C^（R） are X-complexes and U, V ∈ Cr（R） are Y-complexes, then U V Hom（A, U） Hom（A, Y）; A B Hom（B, U） Hom（A, U）. As an application, we give a sufficient condition for the Hom evaluation morphism being invertible.
