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1.
Let Aut$_∗(X)$ denote the group of homotopy classes of self-homotopy equivalences of $X$, which induce identity automorphisms of homology group. We describe a decomposition of Aut$_∗(X_1∨· · ·∨X_n)$ as a product of its simpler subgroups. We consider the subgroup Aut$_Σ(X)$ of all self homotopy classes α of $X$ such that $Σα = 1_{ΣX} : ΣX → ΣX$, and also give some properties of Aut$_Σ(X)$.  相似文献   

2.
For the nonlinear degenerate parabolic equations, how to find an appropriate boundary value condition to ensure the well-posedness of weak solution has been an interesting and challenging problem. In this paper, we develop the general characteristic function method to study the stability of weak solutions based on a partial boundary value condition.  相似文献   

3.
We present results of calculating the matrix elements of the (B0−[`(B)]0\bar B^0 )-mixing operators in the next-to-leading order of the expansion in 1/m b .  相似文献   

4.
In this note we define the property (ω′), a variant of Weyl’s theorem, and establish for a bounded linear operator defined on a Hilbert space the necessary and sufficient conditions for which property (ω′) holds by means of the variant of the essential approximate point spectrum σ1(·) and the spectrum defined in view of the property of consistency in Fredholm and index. In addition, the perturbation of property (ω′) is discussed.  相似文献   

5.
In the note,we establish for a bounded linear operator defined on a Hilbert space the necessary and sufficient conditions for the stability of property(ω) by means of the variant of the essential approximate point spectrum and the induced spectrum of consistency in Fredholm and index.In addition,the stability of property(ω) for H(P) operators is considered.  相似文献   

6.
In this note we study the property (ω), a variant of Weyl's theorem introduced by Rakocevic, by means of the new spectrum. We establish for a bounded linear operator defined on a Banach space a necessary and sufficient condition for which both property (ω) and approximate Weyl's theorem hold. As a consequence of the main result, we study the property (ω) and approximate Weyl's theorem for a class of operators which we call the λ-weak-H(p) operators.  相似文献   

7.
In this paper, we study ∗-simple type $A$ $ω^2$-semigroups in which$\mathcal{D}^∗ =\widetilde{D}$and $\mathcal{D}^∗|_{E_S} = \mathcal{M}_d$ by the generalized Bruck-Reilly extension and obtain its structure theorem. We also obtain a criterion for isomorphisms of two such semigroups.  相似文献   

8.
In this paper we introduce the notion of (f,ω)-compatible pair (B,H), by which we construct a Hopf algebra in the category HHYD of Yetter-Drinfeld H-modules by twisting the comultiplication of B. We also study the property of ω-smash coproduct Hopf algebras Bω H.  相似文献   

9.
This paper deals with the stability analysis of $\theta -$methods for the numerical solution of delay differential equations (DDEs). We focus on the behaviour of such methods in the solution of the linear test equation $y^{\prime}(t)=a(t)y(t)+b(t)y(t-\tau )$, where $\tau >0$, $a(t)$ and $b(t)$ are functions from $R$ to $C$. It is proved that the linear $\theta -$method and the one-leg $\theta -$method are TGP-stable if and only if $\theta =1.$  相似文献   

10.
A closed subspace $M$ of the Hardy space $H^2(\mathbb{D}^2)$ over the bidisk is called submodule if it is invariant under multiplication by coordinate functions $z$ and $w.$ Whether every finitely generated submodule is Hilbert-Schmidt is an unsolved problem. This paper proves that every finitely generated submodule $M$ containing $θ(z)−\varphi(w)$ is Hilbert-Schmidt, where $θ(z),$ $\varphi(w)$ are two finite Blaschke products.  相似文献   

11.
12.
13.
It is proved that the lattice of all τ -closed totally saturated formations of finite groups is \mathfrakG \mathfrak{G} -separable.  相似文献   

14.
Yang  N.  Wu  Zh.  Revin  D. O. 《Siberian Mathematical Journal》2022,63(2):387-394
Siberian Mathematical Journal - Let  $ \pi $ be a proper subset of the set of all primes and $ {|\pi|\geq 2} $ . Denote the smallest prime not in  $ \pi $ by  $...  相似文献   

15.
We study maximal Cohen–Macaulay modules over the hypersurface ring K being a field. Infinite families of non-isomorphic indecomposable maximal Cohen–Macaulay modules of arbitrary number of minimal generators or of arbitrary rank are constructed. The second author was supported by the CEEX Programme of the Romanian Ministry of Education and Research, contract 2-CEX 06-11-20/25.07.06, and the grant CNCSIS 1055/ 2006.  相似文献   

16.
In this note we study the property(ω1),a variant of Weyl's theorem by means of the single valued extension property,and establish for a bounded linear operator defined on a Banach space the necessary and sufficient condition for which property(ω1) holds.As a consequence of the main result,the stability of property(ω1) is discussed.  相似文献   

17.
本文引进了具有性质(Gk)的Wakamatsu倾斜模的概念,并用同调有限子范畴的性质对其进行了刻画.所得结果推广了黄兆泳在文献[1]和[11]中的工作.  相似文献   

18.
The present paper deals with the gracefulness of unconnected graph $(jC_{4n}) ∪ P_m$, and proves the following result: for positive integers $n$, $j$ and $m$ with $n ≥ 1$, $j ≥ 2$, the unconnected graph $(jC_{4n}) ∪ P_m$ is a graceful graph for $m = j − 1$ or $m ≥ n + j$, where $C_{4n}$ is a cycle with $4n$ vertexes, $P_m$ is a path with $m + 1$ vertexes, and $(jC_{4n}) ∪ P_m$ denotes the disjoint union of $j − C_{4n}$ and $P_m$.  相似文献   

19.
We study the representation theory of the solution space of the one-dimensional Schrödinger equation with singular potential V λ (x) = λx ?2 as a representation of \(\widetilde{SL(2,\mathbb{R})}\). The subspace of solutions for which the action globalizes is constructed via nonstandard induction outside the semisimple category. By studying the subspace of K-finite vectors in this space, a distinguished family of potentials, parametrized by the triangular numbers is shown to generate a global representation of \(\widetilde{SL(2,\mathbb{R})}\) ? H 3, where H 3 is the three-dimensional Heisenberg group.  相似文献   

20.
We call T C B(H) consistent in Fredholm and index (briefly a CFI operator) if for each B ∈ B(H), TB and BT are Fredholm together and the same index of B, or not Fredholm together. Using a new spectrum defined in view of the CFI operator, we give the equivalence of Weyl's theorem and property (ω) for T and its conjugate operator T^*. In addition, the property (ω) for operator matrices is considered.  相似文献   

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