In this paper,we study two types of the Ding injective dimensions of complexes.First,we provide some equivalent characterizations of the dimension related to the special Ding injec-tive preenvelopes.Furthermore,we con...In this paper,we study two types of the Ding injective dimensions of complexes.First,we provide some equivalent characterizations of the dimension related to the special Ding injec-tive preenvelopes.Furthermore,we consider the relationship between the dimensions Dipd(Y)and Did(Y)of the complex Y,where Dipd(Y)denotes the dimension associated with special Ding injective preenvelopes,and Did(Y)denotes the dimension associated with DG-injective resolutions.It is demonstrated that Dipd(Y)=Did(Y)for any bounded complex Y.展开更多
Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module...Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module R/p.展开更多
The definition of principally pseudo injectivity motivates us to generalize tae notion of injectivity, noted SP pseudo injectivity. The aim of this paper is to investigate characterizations and properties of SP pseudo...The definition of principally pseudo injectivity motivates us to generalize tae notion of injectivity, noted SP pseudo injectivity. The aim of this paper is to investigate characterizations and properties of SP pseudo injective modules. Various results are devel- oped, many extending known results. As applications, we give some characterizations on Noetherian rings, QI rings, quasi-Frobenius rings.展开更多
In this article, we introduce and study the concept of n-Gorenstein injective (resp., n-Gorenstein flat) modules as a nontrivial generalization of Gorenstein injective (resp., Gorenstein flat) modules. We investig...In this article, we introduce and study the concept of n-Gorenstein injective (resp., n-Gorenstein flat) modules as a nontrivial generalization of Gorenstein injective (resp., Gorenstein flat) modules. We investigate the properties of these modules in various ways. For example, we show that the class of n-Gorenstein injective (resp., n -Gorenstein flat) modules is closed under direct sums and direct products for n ≥ 2. To this end, we first introduce and study the notions of n-injective modules and n-flat modules.展开更多
A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominatin...A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominating set is denoted by and is called the Inj-equitable domination number of G. In this paper, we introduce the injective equitable domination of a graph and study its relation with other domination parameters. The minimal injective equitable dominating set, the injective equitable independence number , and the injective equitable domatic number are defined.展开更多
In this paper, we study some properties of n-strongly Gorenstein projective,injective and flat modules, and discuss some connections between n-strongly Gorenstein injective, projective and flat modules. Some applicati...In this paper, we study some properties of n-strongly Gorenstein projective,injective and flat modules, and discuss some connections between n-strongly Gorenstein injective, projective and flat modules. Some applications are given.展开更多
A coloring of edges of a graph G is injective if for any two distinct edges e1 and e2,the coloring of e1 and e2 are distinct if they are at distance 2 in G or in a common 3-cycle.The injective chromatic index of G is ...A coloring of edges of a graph G is injective if for any two distinct edges e1 and e2,the coloring of e1 and e2 are distinct if they are at distance 2 in G or in a common 3-cycle.The injective chromatic index of G is the minimum number of colors needed for an injective edge coloring of G.It was conjectured that the injective chromatic index of any subcubic graph is at most 6.In this paper,we partially confirm this conjecture by showing that the injective chromatic index of any claw-free subcubic graph is less than or equal to 6.The bound 6 is tight and our proof implies a linear-time algorithm for finding an injective edge coloring using at most 6 colors for such graphs.展开更多
As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelopes of...As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelopes of an extension of a Hilbert C * modules over a C * algebra is introduced, and is characterized in terms of the injectivity and essence. It is shown that every Hilbert C * module has a unique (up to H isometrics) injective envelope if it exists. It is also shown that an extension of a Hilbert C * module is an injective envelope if and only if it is an injective and essential extension. Moreover, every Hilbert C * module over a W * algebra has a unique (up to H isometrics) injective envelope and the injective envelope of a Hilbert C * module H is maximal essential extension of H .展开更多
Many-valued logic system always plays a crucial role in artificial intelligence.In orderfurther to study many-valued logic system as well as logic with truth-values in a lattice,the con-cept of lattice implication alg...Many-valued logic system always plays a crucial role in artificial intelligence.In orderfurther to study many-valued logic system as well as logic with truth-values in a lattice,the con-cept of lattice implication algebra was proposed in reference[1]and the corresponding logic systemwas also investigated.In this paper.we focus on a kind of important lattice implication algebra,i.e..injective lattice implication algebra.Some properties are discussed and also the charaeteristic ofits structure is given.展开更多
Let Z/(p^e) be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/(p^e), there is a unique p-adic decomposition a- = a-0 +a-1 .p +… + a-e-l .p^e-1 where each a-...Let Z/(p^e) be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/(p^e), there is a unique p-adic decomposition a- = a-0 +a-1 .p +… + a-e-l .p^e-1 where each a-i can be regarded as a sequence over Z/(p), 0 ≤ i ≤ e - 1. Let f(x) be a primitive polynomial over Z/(p^e) and G'(f(x),p^e) the set of all primitive sequences generated by f(x) over Z/(p^e). For μ(x) ∈ Z/(p)[x] with deg(μ(x)) ≥ 2 and gad(1 + deg(μ(x)),p- 1) = 1, setφe-1 (x0, x1,… , xe-1) = xe-1. [μ(xe-2) + ηe-3(x0, X1,…, xe-3)] + ηe-2(x0, X1,…, xe-2) which is a function of e variables over Z/(p). Then the compressing mapφe-1 : G'(f(x),p^e) → (Z/(p))^∞ ,a-→φe-1(a-0,a-1, … ,a-e-1) is injective. That is, for a-,b-∈ G'(f(x),p^e), a- = b- if and only if φe-1 (a-0,a-1, … ,a-e-1) = φe-1(b-0, b-1,… ,b-e-1). As for the case of e = 2, similar result is also given. Furthermore, if functions φe-1 and ψe-1 over Z/(p) are both of the above form and satisfy φe-1(a-0,a-1,…,a-e-1)=ψe-1(b-0, b-1,… ,b-e-1) for a-,b-∈G'(f(x),p^e), the relations between a- and b-, φe-1 and ψe-1 are discussed展开更多
In this paper, we mainly investigate some properties of strongly n-Gorenstein projective, injective and flat modules under the extension of rings, which mainly including excellent extensions, morita equivalences, poly...In this paper, we mainly investigate some properties of strongly n-Gorenstein projective, injective and flat modules under the extension of rings, which mainly including excellent extensions, morita equivalences, polynomial extensions and localizations.展开更多
In this article, we will present a particularly remarkable partitioning method of any infinite set with the aid of non-surjective injective maps. The non-surjective injective maps from an infinite set to itself consti...In this article, we will present a particularly remarkable partitioning method of any infinite set with the aid of non-surjective injective maps. The non-surjective injective maps from an infinite set to itself constitute a semigroup for the law of composition bundled with certain properties allowing us to prove the existence of remarkable elements. Not to mention a compatible equivalence relation that allows transferring the said law to the quotient set, which can be provided with a lattice structure. Finally, we will present the concept of Co-injectivity and some of its properties.展开更多
Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homo...Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-injective oriented colouring problem. A dichotomy theorem is proved in each case.展开更多
We show that a QWEP von Neumann algebra has the weak* positive approximation property if and only if it is seemingly injective in the following sense: there is a factorization of the identity of IdM= vu : M→uB(H)...We show that a QWEP von Neumann algebra has the weak* positive approximation property if and only if it is seemingly injective in the following sense: there is a factorization of the identity of IdM= vu : M→uB(H)→vM with u normal, unital, positive and v completely contractive. As a corollary, if M has a separable predual, M is isomorphic(as a Banach space) to B(l2). For instance this applies(rather surprisingly) to the von Neumann algebra of any free group. Nevertheless, since B(H) fails the approximation property(due to Szankowski) there are M ’s(namely B(H)** and certain finite examples defined using ultraproducts) that are not seemingly injective.Moreover, for M to be seemingly injective it suffices to have the above factorization of I dM through B(H) with u, v positive(and u still normal).展开更多
The notion of DG-Gorenstein injective complexes is studied in this article.It is shown that a complex G is DG-Gorenstein injective if and only if G is exact with Zn(G)Gorenstein injective in R-Mod for each n∈Zand ...The notion of DG-Gorenstein injective complexes is studied in this article.It is shown that a complex G is DG-Gorenstein injective if and only if G is exact with Zn(G)Gorenstein injective in R-Mod for each n∈Zand any morphism f:E→G is null homotopic whenever E is a DG-injective complex.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.12061061)the Young Talents Team Project of Gansu Province(Grant No.2025QNTD49)+1 种基金Lanshan Talent Project of Northwest Minzu University(Grant No.Xbmulsrc202412)Longyuan Young Talents of Gansu Province.
摘要In this paper,we study two types of the Ding injective dimensions of complexes.First,we provide some equivalent characterizations of the dimension related to the special Ding injec-tive preenvelopes.Furthermore,we consider the relationship between the dimensions Dipd(Y)and Did(Y)of the complex Y,where Dipd(Y)denotes the dimension associated with special Ding injective preenvelopes,and Did(Y)denotes the dimension associated with DG-injective resolutions.It is demonstrated that Dipd(Y)=Did(Y)for any bounded complex Y.
基金Supported in part by Open program of Key Laboratory of Smart Photoelectric System Sensing and Application in Sichuan Provincial Universities—Research on the applicability of the theory of 3D in intelligent3D visual and auditory systems for smart management(No.ZNGD2410)2nd Batch of High Level Talent Research Launch Project in 2023 of Sichuan University of Arts and Sciences(No.2023RC009Z)。
摘要In this paper,we present some results of the finitistic injective dimension of pullbacks of rings in terms of strongly C2rings.
基金This research is in part supported by a grant from IPM.
摘要Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module R/p.
基金Supported by the Ph.D.Programs Foundation of Ministry of Education of China(200803570003)
摘要The definition of principally pseudo injectivity motivates us to generalize tae notion of injectivity, noted SP pseudo injectivity. The aim of this paper is to investigate characterizations and properties of SP pseudo injective modules. Various results are devel- oped, many extending known results. As applications, we give some characterizations on Noetherian rings, QI rings, quasi-Frobenius rings.
基金The NSF(11501451)of Chinathe Fundamental Research Funds(31920150038)for the Central Universities and XBMUYJRC(201406)
摘要In this article, we introduce and study the concept of n-Gorenstein injective (resp., n-Gorenstein flat) modules as a nontrivial generalization of Gorenstein injective (resp., Gorenstein flat) modules. We investigate the properties of these modules in various ways. For example, we show that the class of n-Gorenstein injective (resp., n -Gorenstein flat) modules is closed under direct sums and direct products for n ≥ 2. To this end, we first introduce and study the notions of n-injective modules and n-flat modules.
摘要A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominating set is denoted by and is called the Inj-equitable domination number of G. In this paper, we introduce the injective equitable domination of a graph and study its relation with other domination parameters. The minimal injective equitable dominating set, the injective equitable independence number , and the injective equitable domatic number are defined.
基金Supported by the National Natural Science Foundation of China(11361051) Supported by the Program for New Century Excellent the Talents in University(NCET-13-0957)
摘要In this paper, we study some properties of n-strongly Gorenstein projective,injective and flat modules, and discuss some connections between n-strongly Gorenstein injective, projective and flat modules. Some applications are given.
基金Supported by the National Natural Science Foundation of China(Grant No.11771080).
摘要A coloring of edges of a graph G is injective if for any two distinct edges e1 and e2,the coloring of e1 and e2 are distinct if they are at distance 2 in G or in a common 3-cycle.The injective chromatic index of G is the minimum number of colors needed for an injective edge coloring of G.It was conjectured that the injective chromatic index of any subcubic graph is at most 6.In this paper,we partially confirm this conjecture by showing that the injective chromatic index of any claw-free subcubic graph is less than or equal to 6.The bound 6 is tight and our proof implies a linear-time algorithm for finding an injective edge coloring using at most 6 colors for such graphs.
摘要As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelopes of an extension of a Hilbert C * modules over a C * algebra is introduced, and is characterized in terms of the injectivity and essence. It is shown that every Hilbert C * module has a unique (up to H isometrics) injective envelope if it exists. It is also shown that an extension of a Hilbert C * module is an injective envelope if and only if it is an injective and essential extension. Moreover, every Hilbert C * module over a W * algebra has a unique (up to H isometrics) injective envelope and the injective envelope of a Hilbert C * module H is maximal essential extension of H .
基金Supported by the National Science Foundation of China(No.69874033).
摘要Many-valued logic system always plays a crucial role in artificial intelligence.In orderfurther to study many-valued logic system as well as logic with truth-values in a lattice,the con-cept of lattice implication algebra was proposed in reference[1]and the corresponding logic systemwas also investigated.In this paper.we focus on a kind of important lattice implication algebra,i.e..injective lattice implication algebra.Some properties are discussed and also the charaeteristic ofits structure is given.
基金Supported by the National Natural Science Foundation of China(60673081)863 Program(2006AA01Z417)
摘要Let Z/(p^e) be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/(p^e), there is a unique p-adic decomposition a- = a-0 +a-1 .p +… + a-e-l .p^e-1 where each a-i can be regarded as a sequence over Z/(p), 0 ≤ i ≤ e - 1. Let f(x) be a primitive polynomial over Z/(p^e) and G'(f(x),p^e) the set of all primitive sequences generated by f(x) over Z/(p^e). For μ(x) ∈ Z/(p)[x] with deg(μ(x)) ≥ 2 and gad(1 + deg(μ(x)),p- 1) = 1, setφe-1 (x0, x1,… , xe-1) = xe-1. [μ(xe-2) + ηe-3(x0, X1,…, xe-3)] + ηe-2(x0, X1,…, xe-2) which is a function of e variables over Z/(p). Then the compressing mapφe-1 : G'(f(x),p^e) → (Z/(p))^∞ ,a-→φe-1(a-0,a-1, … ,a-e-1) is injective. That is, for a-,b-∈ G'(f(x),p^e), a- = b- if and only if φe-1 (a-0,a-1, … ,a-e-1) = φe-1(b-0, b-1,… ,b-e-1). As for the case of e = 2, similar result is also given. Furthermore, if functions φe-1 and ψe-1 over Z/(p) are both of the above form and satisfy φe-1(a-0,a-1,…,a-e-1)=ψe-1(b-0, b-1,… ,b-e-1) for a-,b-∈G'(f(x),p^e), the relations between a- and b-, φe-1 and ψe-1 are discussed
基金Supported by the NNSF of China(10901129)Supported by the SRFDP(20096203120001)
摘要In this paper, we mainly investigate some properties of strongly n-Gorenstein projective, injective and flat modules under the extension of rings, which mainly including excellent extensions, morita equivalences, polynomial extensions and localizations.
摘要In this article, we will present a particularly remarkable partitioning method of any infinite set with the aid of non-surjective injective maps. The non-surjective injective maps from an infinite set to itself constitute a semigroup for the law of composition bundled with certain properties allowing us to prove the existence of remarkable elements. Not to mention a compatible equivalence relation that allows transferring the said law to the quotient set, which can be provided with a lattice structure. Finally, we will present the concept of Co-injectivity and some of its properties.
摘要Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-injective oriented colouring problem. A dichotomy theorem is proved in each case.
摘要We show that a QWEP von Neumann algebra has the weak* positive approximation property if and only if it is seemingly injective in the following sense: there is a factorization of the identity of IdM= vu : M→uB(H)→vM with u normal, unital, positive and v completely contractive. As a corollary, if M has a separable predual, M is isomorphic(as a Banach space) to B(l2). For instance this applies(rather surprisingly) to the von Neumann algebra of any free group. Nevertheless, since B(H) fails the approximation property(due to Szankowski) there are M ’s(namely B(H)** and certain finite examples defined using ultraproducts) that are not seemingly injective.Moreover, for M to be seemingly injective it suffices to have the above factorization of I dM through B(H) with u, v positive(and u still normal).
基金This work was supported by the National Natural Science Foundation of China(grant no.11501451)the Funds for Talent Introduction of Northwest Minzu University(grant no.XBMUYJRC201406).
摘要The notion of DG-Gorenstein injective complexes is studied in this article.It is shown that a complex G is DG-Gorenstein injective if and only if G is exact with Zn(G)Gorenstein injective in R-Mod for each n∈Zand any morphism f:E→G is null homotopic whenever E is a DG-injective complex.