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The notion of U-exact sequence in modules over rings was introduced in [20] as a generalization of {0}-exact sequence. In this paper, we prove further results on U-exact and V -coexact sequences where V is induced by U. As shown in the commutative diagram fig. 1, wherein if row-1 is U-exact and row-2 is U'-exact, then we prove that the sequence (0) → ker f'→ ker f → ker f" is (ker f"∩U)-exact, and the sequence (0) → coker f'→ coker f → coker f" is (U' +Im f"/Im f")-exact. We provide explicit examples of the existence of U-exact and U'-coexactness. [ABSTRACT FROM AUTHOR]

In this paper, the (Co)homology theory of pure algebra will be studied. We aim to study the homological theory of cyclic homology and its properties. The triviality property of cohomology groups of algebras will be obtained. We will study the Mayer-Vietortis of cyclic homology. The long exact sequence of cyclic homology and the relation between cyclic homology and dihedral homology will be proved. We will introduce the proof of isomorphism HCn(A×A′)≅HCn(A)⊕HCn(A′) and the definition of Morita invariance for cyclic homology.

The objective of this study is to calculate the K-Cohomology invariants of certain classification spaces of homotopy groups in short exact sequences, where the computation is done using properties of the K-theoretical features. For these packages we use various applications including K-theory Algebra, which transformed the theory of operator algebra from a smaller branch of functional analysis into a topic with deep and wide application areas in all algebra and topology in mathematics.

The largest class of multi-valued systems satisfying the module-like axioms are the hyper modules. The main tools concerning the class of Hv -- (R -- S)-bi-modules are fundamental relations. First we define Hv -- (R -- S)-hyper-bi-modules and investigate exact secqenses in this field and find equivalent conditions of exactness. [ABSTRACT FROM AUTHOR]

We prove that the category of F-coalgebras admits exact sequences, under condition F preserves pullbacks; the underlying category 풞 is assumed to be cocomplete with epi-(regular mono) factorizations, finite products and exact sequences. [ABSTRACT FROM AUTHOR]

Finite element methods developed for unfitted meshes have been widely applied to various interface problems. However, many of them resort to non-conforming spaces for approximation, which is a critical obstacle for the extension to $\textbf{H}(\text{curl})$ equations. This essential issue stems from the underlying Sobolev space $\textbf{H}^s(\text{curl};\,\Omega)$ , and even the widely used penalty methodology may not yield the optimal convergence rate. One promising approach to circumvent this issue is to use a conforming test function space, which motivates us to develop a Petrov–Galerkin immersed finite element (PG-IFE) method for $\textbf{H}(\text{curl})$ -elliptic interface problems. We establish the Nédélec-type IFE spaces and develop some important properties including their edge degrees of freedom, an exact sequence relating to the $H^1$ IFE space and optimal approximation capabilities. We analyse the inf-sup condition under certain assumptions and show the optimal convergence rate, which is also validated by numerical experiments. [ABSTRACT FROM AUTHOR]

We prove a number of results on the survival of the type-I property under extensions of locally compact groups: (a) that given a closed normal embedding \mathbb {N}\trianglelefteq \mathbb {E} of locally compact groups and a twisted action (\alpha,\tau) thereof on a (post)liminal C^*-algebra A the twisted crossed product A\rtimes _{\alpha,\tau }\mathbb {E} is again (post)liminal and (b) a number of converses to the effect that under various conditions a normal, closed, cocompact subgroup \mathbb {N}\trianglelefteq \mathbb {E} is type-I as soon as \mathbb {E} is. This happens for instance if \mathbb {N} is discrete and \mathbb {E} is Lie, or if \mathbb {N} is finitely-generated discrete (with no further restrictions except cocompactness). Examples show that there is not much scope for dropping these conditions. In the same spirit, call a locally compact group \mathbb {G} type-I-preserving if all semidirect products \mathbb {N}\rtimes \mathbb {G} are type-I as soon as \mathbb {N} is, and linearly type-I-preserving if the same conclusion holds for semidirect products V\rtimes \mathbb {G} arising from finite-dimensional \mathbb {G}-representations. We characterize the (linearly) type-I-preserving groups that are (1) discrete-by-compact-Lie, (2) nilpotent, or (3) solvable Lie. [ABSTRACT FROM AUTHOR]

In this paper we define the concepts of a "strict morphism" as a suitable map between geometric spaces (as a generalization of hyperstructures), and its kernel. Then we introduce the concepts of a "quotient geometric space", an "exact sequence", an "exact hypersequence", a "homology" and a "hyperhomology" of geometric spaces. Finally we generalize some famous theorems from groups and modules in this direction, such as the "isomorphism theorem", the "five short lemma", the "snake lemma", the "exact triangle", etc., by some conditions that are naturally valid for groups. [ABSTRACT FROM AUTHOR]

The main objective of the research is to study the first natural triangular representation of the symmetric groups over a field K of characteristic p≠ 2 which deals with the partition λ = (n − 4,3,1) of the positive integer n. Furthermore, this work has proven that the S(n − 4,3,1) is a submodule of F1 . The F1 = KSn(x2x4x6x7² −x2x3x6x7² − x2x4x5x7² + x²x³x5x7² ) can be only split whenp|(n − 5). الهدف من هذا البحث هو دراسة [ABSTRACT FROM AUTHOR]

The notion of a U-exact sequence is a generalization of the exact sequence. In this paper, we introduce a rough U-exact sequence in a rough group in an approximation space. Furthermore, we provide the properties of the rough U-exact sequence in a rough group.

A (right) module bundle over an algebra bundle ξ = (ξ; p;X) is a vector bundle M=(M,q,X) together with a morphism Ф: M ⊕ ξ-M which induces a right ξx-module structure onMx for each x ∊ X. In this paper, we prove some important results involving exact sequences of ξ-module bundles, mainly, the snake lemma. [ABSTRACT FROM AUTHOR]

A V-cycle multigrid method for the Hellan–Herrmann–Johnson (HHJ) discretization of the Kirchhoff plate bending problems is developed in this paper. It is shown that the contraction number of the V-cycle multigrid HHJ mixed method is bounded away from one uniformly with respect to the mesh size. The uniform convergence is achieved for the V-cycle multigrid method with only one smoothing step and without full elliptic regularity assumption. The key is a stable decomposition of the kernel space which is derived from an exact sequence of the HHJ mixed method, and the strengthened Cauchy Schwarz inequality. Some numerical experiments are provided to confirm the proposed V-cycle multigrid method. The exact sequences of the HHJ mixed method and the corresponding commutative diagram is of some interest independent of the current context.

Bousfield introduced an algebraic category of modules that reflects the structure detected by p-localized complex topological K-theory. He constructed, for any module M in this category, a natural 4-term exact sequence 0 → M → U M → U M → M ⊗ Q → 0 , where U denotes the co-free functor, right adjoint to the forgetful functor to Z (p) -modules. Clarke et al. identified the objects of Bousfield's category as the 'discrete' modules for a certain topological ring A, obtained as a completion of the polynomial ring Z (p) [ x ] , and simplified the construction of the Bousfield sequence in this context. We introduce the notion of 'cobasically discrete' R-modules as a clarification of the Clarke et al. modules, noting that these correspond to comodules over the coalgebra that R is dual to. We study analogues of the Bousfield sequence for other polynomial completion rings, noting a variety of behaviour in the last term of the sequence. [ABSTRACT FROM AUTHOR]

Let be a ring, a strictly ordered monoid, and K, L, M are R-modules. Then, we can construct the Generalized Power Series Modules (GPSM) K[[S]], L[[S]], and M[[S]], which are the module over the Generalized Power Series Rings (GPSR) R[[S]]. In this paper, we investigate the property of X[[S]]-sub-exact sequence on GPSM L[[S]] over GPSR R[[S]].

An extension of X by Y is a short exact sequence of quasi Banach modules and homomorphisms 0 -→ Y -→ Z -→ X -→ 0. When properly organized all these extensions constitute a linear space denoted by ExtB(X, Y ), where B is the underlying (Banach) algebra. In this paper we "compute" the spaces of extensions for the Schatten classes when they are regarded in its natural (left) module structure over B = B(H), the algebra of all operators on the ground Hilbert space. Our main results can be summarized as follows: ... In the first case, every extension 0 -→ Sq -→ Z -→ Sp -→ 0 splits and so X = Sq -Sp. In the second case, every self-extension of Sp arises (and gives rise) to a minimal extension of S1 in the quasi Banach category, that is, a short exact sequence 0 -→ C -→ M -→ S1 -→ 0. In the third case, each extension corresponds to a "twisted Hilbert space", that is, a short exact sequence 0 -→ H -→ T -→ H -→ 0. Thus, the subject of the paper is closely connected to the early "three-space" problems studied (and solved) in the seventies by Enflo, Lindenstrauss, Pisier, Kalton, Peck, Ribe, Roberts, and others. [ABSTRACT FROM AUTHOR]

Torsion theories are here extended to categories equipped with an ideal of 'null morphisms', or equivalently a full subcategory of 'null objects'. Instances of this extension include closure operators viewed as generalised torsion theories in a 'category of pairs', and factorization systems viewed as torsion theories in a category of morphisms. The first point has essentially been treated in [15].

The k-Cauchy–Fueter complex in quaternionic analysis was generalized to the Heisenberg group in a previous paper (Ren et al., in Adv Appl Clifford Algebras 30(2): Paper No. 20, 2020). But it is not known whether this differential complex is exact or not. In this paper, we apply the Penrose transform (the twistor method) to a double fibration of homogeneous spaces of SO (2 N , C) to prove its exactness on the Heisenberg group. [ABSTRACT FROM AUTHOR]

In this paper we calculate cohomology of a classical Lie algebra of type A 2 over an algebraically field k of characteristic p = 3 with coefficients in simple modules. To describe their structure we will consider them as modules over an algebraic group SL 3( k ) . In the case of characteristic p = 3 , there are only two peculiar simple modules: a simple that module isomorphic to the quotient module of the adjoint module by the center, and a one-dimensional trivial module. The results on the cohomology of simple nontrivial module are used for calculating the cohomology of the adjoint module. We also calculate cohomology of the simple quotient algebra Lie of A 2 by the center.

In this work, we prove by employing mapping Cone that the sequence and the subsequence of the characteristic-zero are exact and subcomplex respectively in the case of partition (6,6,4) . [ABSTRACT FROM AUTHOR]

Let F be an endofunctor of a category C. We prove isomorphism theorems for F -coalgebras under condition that the underlying category C is exact; that is, regular with exact sequences. Also, F is not assumed to preserve pullbacks.

Let X be a Hopf manifold with non-Abelian fundamental group and E be a holomorphic vector bundle over X, with trivial pull-back to ℂn − {0}. The authors show that there exists a line bundle L over X such that E ⊗ L has a nowhere vanishing section. It is proved that in case dim(X) ≥ 3, π*(E) is trivial if and only if E is filtrable by vector bundles. With the structure theorem, the authors get the cohomology dimension of holomorphic bundle E over X with trivial pull-back and the vanishing of Chern class of E. [ABSTRACT FROM AUTHOR]

It is well known that the classical diagram lemmas of homological algebra for abelian groups can be generalized to non-abelian group-like structures, such as groups, rings, algebras, loops, etc. In this paper, we establish such a generalization of the "salamander lemma" due to G. M. Bergman, in a self-dual axiomatic context (developed originally by Z. Janelidze), which applies to all usual non-abelian group-like structures and also covers axiomatic contexts such as semi-abelian categories in the sense of G. Janelidze, L. Márki and W. Tholen and exact categories in the sense of M. Grandis. [ABSTRACT FROM AUTHOR]

In this paper, we study an excision theorem of the dihedral and reflexive (co)homology theory of associative algebras. That is, for such an extension, we obtain a six-term exact sequence in the dihedral cohomology. Also, we present and prove the relation between cyclic and dihedral cohomology of algebras and some examples. [ABSTRACT FROM AUTHOR]

The paper deals with the normal extensions of cancellative commutative semigroups and the Toeplitz algebras for those semigroups. By the Toeplitz algebra for a semigroup S one means the reduced semigroup C*-algebra Cr*(S). We study the normal extensions of cancellative commutative semigroups by the additive group ℤn of integers modulo n. Moreover, we assume that such an extension is generated by one element. We present a general method for constructing normal extensions of semigroups which contain no non-trivial subgroups. The Grothendieck group for a given semigroup and the group of all integers are involved in this construction. Examples of such extensions for the additive semigroup of non-negative integers are given. A criterion for a normal extension generated by an element to be isomorphic to a numerical semigroup is given in number-theoretic terms. The results concerning the Toeplitz algebras are the following. For a cancellative commutative semigroup S and its normal extension L generated by one element, there exists a natural embedding the semigroup C*-algebra Cr*(S) into Cr*(L). The semigroup C*-algebra Cr*(L) is topologically ℤn-graded. The results in the paper are announced without proofs. [ABSTRACT FROM AUTHOR]

In this paper, the notion of (short) quasi-exact sequence of S-acts is introduced. We study the behaviour of quasi-exact sequences in regard to some algebraic properties of S-acts including principal weak injectivity, principal weak flatness, regularity and torsion freeness. Moreover, some results concerning commutative diagrams of modules are generalized to acts over monoids. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Qadisiyah Computer Science & Mathematics is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper examines special metrics on compact complex manifolds, and it is notably focused on the notion of super strong Kähler with torsion metric. This condition is related to the strong Kähler with torsion one in the same manner as the strongly Gauduchon condition is related to the Gauduchon one. Moreover, we provide sufficient and necessary conditions so that every strong Kähler with torsion metric on a compact complex manifold is in fact super strong Kähler with torsion. We prove that these conditions are verified on compact complex manifolds satisfying $$\partial \overline{\partial }$$ -lemma but not on 6-dimensional compact complex nilmanifolds. [ABSTRACT FROM AUTHOR]

A straightforward way is offered to convert a system of high order linear functional equations of various type into a system of first order equations. [ABSTRACT FROM AUTHOR]

Different first order representations of high order linear PDEs, depending on which notion of the degree of a polynomial is chosen, are possible. Two notions of degree, namely, the total degree and multi-degree, are standard and the most natural. In our recent article, a straightforward way was provided to convert a system of high order constant coefficient linear PDEs into a system of first order PDEs based on the notion of total degree. In the present article, an analogous development is carried out in the multi-degree setting. [ABSTRACT FROM AUTHOR]

Higher homotopy of graphs has been defined in several articles. However, the existence of a long exact sequence associated to a pair (G, A) has not been touched at. We treat it here. Applied to the discrete spheres, this lead to interesting open questions. Higher homotopy of graphs has been defined in several articles. However, the existence of a long exact sequence associated to a pair (G, A) has not been touched at. We treat it here. Applied to the discrete spheres, this lead to interesting open questions.

In this paper we find a generalization of the snake lemma and Schanuel's lemma in Hv-modules. We define the isomorph sequences and determine the conditions to split the exact sequences in Hv-modules. Some interesting results on these concepts are given. [ABSTRACT FROM AUTHOR]

Quasi module is an axiomatisation of the hyperspace structure based on a module. We proposed this structure in our paper [2]. It can be thought of as a generalisation of the module structure in the sense that every module can be embedded into a quasi module and every quasi module contains a module. The structure of quasi module is designed on a commutative semigroup with an external ring multiplication and a compatible partial order which has a very intrinsic effect in the entire structure and plays a key role in any development of the theory of quasi module. In this paper we have introduced the concept of exact sequence on quasi modules and proved some Theorems related to exact sequences. [ABSTRACT FROM AUTHOR]

We prove that if E and F are large ideals of B(G) for which the associated coaction functors are exact, then the same is true for E ∩ F. We also give an example of a coaction functor whose restriction to the maximal coactions does not come from any large ideal. [ABSTRACT FROM AUTHOR]

A straightforward way requiring no calculations is offered to convert a system of high order constant coefficient linear PDEs into a system of first order PDEs. [ABSTRACT FROM AUTHOR]

In this paper we provide an axiomatic analysis of the classical diagram chasing method of Mac Lane, that relies on duality and chasing elements of pointed sets, which allows one to generalize this method from abelian categories to non-abelian ones. Among the examples where the generalized method can be used are all modular semiexact categories in the sense of Grandis (which include all Puppe-Mitchell exact categories) and sequentiable categories in the sense of Bourn (which include all semi-abelian categories, and in particular, the categories of group-like structures). The method turns out to be closely related to the essential features of these categories. At the same time, in some sense, it simplifies the usual proofs of some of the standard diagram lemmas in them. [ABSTRACT FROM AUTHOR]

The largest class of multivalued systems satisfying the module-like axioms are the Hv -modules. The main tools concerning the class of Hv -modules with the ordinary modules are the fundamental relations. Based on the relation ε* , exact sequences in Hv -modules are defined. In this paper, we introduce the Hv -module M[A] and determine its heart and the connection between equivalence relations ε* M[A] and ε* A . Moreover, we define the M[-] and -[M] functors and investigate the exactness and some concepts related to them. Finally, we prove the five short lemma in Hv -modules. [ABSTRACT FROM AUTHOR]

We study the Bredon-Illman cohomology with local coefficients for a G-space X in the case of G being a totally disconnected, locally compact group. We prove that any short exact sequence of equivariant local coefficients systems on X gives a long exact sequence of the associated Bredon-Illman cohomology groups with local coefficients. [ABSTRACT FROM AUTHOR]

Let V be a vertex operator algebra. The fusion products in this paper are defined by logarithmic intertwining operators. Under this setting, we prove the pure exactness of any extension of the V -module V . Namely, if 0 → Q → ϵ P → ρ V → 0 is a short exact sequence of V -modules and W is a V -module, then 0 → Q ⊠ W → ϵ ⊠ 1 W P ⊠ W → ρ ⊠ 1 W V ⊠ W → 0 is also exact, where we view it as a sequence of g ( V ) -modules. [ABSTRACT FROM AUTHOR]

Abstract: By means of a mixture of linear and nonlinear techniques, the paper treats quasi-Banach function spaces as -modules and studies the basic algebraical constructions and their interactions, placing the emphasis on tensor products. Sample result: if is an exact sequence of -modules and homomorphisms, where Y and Z are function spaces, and V is another function space, then the tensorized sequence is exact too. [Copyright &y& Elsevier]

In this note, a construction of state representations of singular linear time-invariant differential systems is described directly in terms of trajectories. [ABSTRACT FROM AUTHOR]

Higher homotopy of graphs has been defined in several articles. In Dochterman (Hom complexes and homotopy theory in the category of graphs. arXiv math/0605275 v2,28/09/2006, ), the authors asked for a companion homology theory. We define such a theory for the category of unoriented reflexive graphs; it exhibits a long exact sequence for a pair of graphs ( G, A), satisfies an excision property and a Hurewicz theorem. This allows us to compute the top homology of the graphical n-spheres showing that the theory is not trivial and is able to detect n-dimensional holes in a graph. The long-term objective is to compare the homotopy of the topological and graphical spheres. [ABSTRACT FROM AUTHOR]

In this paper, we offer a systematic development of state representation theory for singular linear systems in the behavioural setting of Willems. [ABSTRACT FROM PUBLISHER]

We formulate and prove a “five lemma”, which unifies two independent generalizations of the classical five lemma in an abelian category: the five lemma in a (modular) semi-exact category in the sense of M. Grandis, and the five lemma in a pointed regular protomodular category in the sense of D. Bourn. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In this article, the classical Popov–Belevitch–Hautus controllability test is generalized to higher dimensions. [Copyright &y& Elsevier]

Abstract: It is shown that every centralizer from any “metric function space” to is continuous at the origin of . As a consequence, every short exact sequence of -modules splits if is a “minimal” function space, and in particular if . There are pairs of Orlicz function spaces such that , but . [Copyright &y& Elsevier]

The paper establishes a relation between exact sequences, parametric finite elements, and perfectly matched layer (PML) techniques. We illuminate the analogy between the Piola-like maps used to define parametric H-, H(curl)-, H(div)-, and L-conforming elements, and the corresponding PML complex coordinates stretching for the same energy spaces. We deliver a method for obtaining PML-stretched bilinear forms (constituting the new weak formulation for the original problem with PML absorbing boundary layers) directly from their classical counterparts. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that diagram lemmas for abelian groups (and more generally in abelian categories) used in algebraic topology, can be suitably extended to “non-abelian” structures such as groups, rings, loops, etc. Moreover, they are equivalent to properties which arise in the axiomatic study of these structures. For the five lemma this is well known, and in the present paper we establish this for the snake lemma and the lemma, which, when suitably formulated, turn out to be equivalent to each other for all (pointed) algebraic structures, and also in general categories of a special type. In particular, we show that among varieties of universal algebras, they are satisfied precisely in the so-called (pointed) ideal determined varieties. [Copyright &y& Elsevier]

This paper is concerned with the second change of rings theorems for the Gorenstein homological dimensions. More precisely, we give the ultimate versions of these theorems relatively to these new invariants. [ABSTRACT FROM AUTHOR]