共查询到20条相似文献,搜索用时 12 毫秒
1.
《Applied Mathematics Letters》2000,13(2):83-90
The notions of essential and inessential maps are given for new classes of maps. In addition, generalizations of Krasnoselskii's compression and expansion theorem in a cone are presented. 相似文献
2.
Marilyn Breen 《Israel Journal of Mathematics》1972,12(4):347-355
LetS be a closed connected subset of a Hausdorff linear topological space,Q the points of local nonconvexity ofS, E the essential members ofQ, N the inessential. IfS~Q is connected, then the following are true: Theorem 1.If Q ?Øis countable, then S is planar. Theorem 2.If Q is finite and nonempty, then cardE≧cardN+1. Theorem 3.If SυR 2 and N is infinite, then E is infinite. 相似文献
3.
Giannina Beccari 《Journal of Pure and Applied Algebra》2011,215(7):1726-1736
In this paper we introduce the concept of inessential element of a standard basis B(I), where I is any homogeneous ideal of a polynomial ring. An inessential element is, roughly speaking, a form of B(I) whose omission produces an ideal having the same saturation as I; it becomes useless in any dehomogenization of I with respect to a linear form. We study the properties of B(I) linked to the presence of inessential elements and give some examples. 相似文献
4.
5.
Eugeniu Spinu 《Journal of Mathematical Analysis and Applications》2011,383(2):259-264
We consider the following three closed algebraic ideals of operators on a Banach lattice: compact, strictly singular, and inessential operators. Suppose that 0?A?B and B is compact or strictly singular. We show that, under certain assumptions, A (or some power of A) is inessential. 相似文献
6.
We show that, for a rationally inessential orientable closed n-manifold M whose fundamental group is a duality group, the macroscopic dimension of its universal cover [(M)\tilde]\tilde M is strictly less than n: dim
MC
[(M)\tilde] < n\tilde M < n. As a corollary, we obtain the following partial result towards Gromov’s conjecture 相似文献
7.
The size of the perturbation class {SL(E)S has closed range}+I(E) is studied, whereE is a Banach space andI(E) stands for various classical operator ideals. For instance, it is shown for the ideal consisting of the inessential operators that the resulting perturbation class does not exhaust the class of bounded linear operators under natural structural conditions onE. It is known from a recent result of Gowers and Maurey that some conditions are needed.Partially supported by the Academy of Finland 相似文献
8.
S. ter Horst M. Messerschmidt A.C.M. Ran M. Roelands M. Wortel 《Indagationes Mathematicae》2018,29(5):1350-1361
In recent years the coincidence of the operator relations equivalence after extension (EAE) and Schur coupling (SC) was settled for the Hilbert space case. For Banach space operators, it is known that SC implies EAE, but the converse implication is only known for special classes of operators, such as Fredholm operators with index zero and operators that can in norm be approximated by invertible operators. In this paper we prove that the implication EAE SC also holds for inessential Banach space operators. The inessential operators were introduced as a generalization of the compact operators, and include, besides the compact operators, also the strictly singular and strictly co-singular operators; in fact they form the largest ideal such that the invertible elements in the associated quotient algebra coincide with (the equivalence classes of) the Fredholm operators. 相似文献
9.
V. P. Orevkov 《Journal of Mathematical Sciences》1982,20(4):2351-2357
The first method is based on the familiar method of lowering thinnings downwards and is a further development of the lemmas on weeding of [1]. The second method is based on the use of sufficiently wide classes of sequents, for which derivability in the intuitionistic predicate calculus coincides with derivability in the classical predicate calculus and the familiar property of disjunction is true. By this method one can get, e.g., a syntactic proof of the following assertion. If the positive formula A is derivable in the theory of groups under additional assumptions of the form then A is also derivable in the theory of groups without these assumptions. As the third method there is proposed a syntactically formulated test for the conservativeness of extensions of intuitionistic axiomatic theories. With the help of this test one can get, for example, a syntactic proof of the hereditary undecidability of the intuitionistic theory of equality, with additional axioms which are the formula, all formulas of the form and all negations of formulas derivable in the classical predicate calculus.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 88, pp. 163–175, 1979. 相似文献
10.
G. Hessenberger 《Archiv der Mathematik》2000,74(6):438-440
For a semiprimitive Banach Jordan system (algebra, triple system or pair) the ideal of inessential elements and the set of properly Riesz elements coincide. A relation between quasi-Fredholm, Riesz, and inessential elements is established and the Generalized Ruston Characterization is given. 相似文献
11.
Q. Luo 《Journal of Optimization Theory and Applications》1999,102(2):433-438
In this note, the concept of essential component of optimum solutions is introduced. We obtain necessary and sufficient conditions for the existence of one essential component or one essential optimum solution in the optimum solution set of the optimization problems. 相似文献
12.
设算子S和T拟相似,应用算子谱的精密结构的分析,证明了Browder本质谱σB(S)的连通分支与σB(T)的某些子集的相交关系以及左本质谱σle(S)的连通分支与本质谱σe(T)的某些子集的相交关系,给出左本质谱σle(S)的连通分支与σle(T)相交的充分条件和充要条件. 相似文献
13.
Fabrizio Broglia 《Annali di Matematica Pura ed Applicata》1986,146(1):185-216
Sunto In questo lavoro si danno condizioni sufficienti per un ricoprimento di una varietà differenziabile V affinchè il suo nerbo abbia lo stesso tipo P.L. di V e si prova l'esistenza di una larga classe di siffatti ricoprimenti.
The author is member of G.N.S.A.G.A. of the C.N.R. and partially supported by a N.A.T.O.-C.N.R. fellowship. 相似文献
The author is member of G.N.S.A.G.A. of the C.N.R. and partially supported by a N.A.T.O.-C.N.R. fellowship. 相似文献
14.
苏维钢 《应用泛函分析学报》2006,8(3):284-288
利用算子谱的精密结构的分析方法,给出算子S和T拟相似时Kato本质谱σK(S)的一个连通分支与σK(T)相交的充分条件和充要条件,同时证明了Browder本质谱σB(S)的每一个连通分支与Kato本质谱σK(T)的某些子集的交集是非空的. 相似文献
15.
16.
进上步研究了生产经济平衡的稳定性,讨论了生产经济平衡“集合值”的稳定性,证明了生产经济平衡点集至少存在一个极小本质集且每一极小本质集是连通的,从而能够给出本质连通分支的存在性。 相似文献
17.
18.
Using an elementary approach, we present new coincidence principles for general classes of maps. 相似文献
19.
《Journal of Functional Analysis》1987,75(2):362-381
Upper bounds are derived for the large time behavior of the heat kernel on Riemannian manifolds whose essential spectrum has a positive lower bound. Applications include a relative signature theorem and the construction of bounded harmonic functions. 相似文献
20.
An extension operator c in a category is an assignment, to each object A a monomorphism c
A
: AcA. Seeking to approximate such a c by a functor, in our earlier paper Maximum monoreflections, we showed that with some hypotheses on the category, and on c, there is a monoreflection (c) maximum beneath c. Thus, in a suitable category of rings, using the complete ring of quotients operator Q, each object A has a maximum functorial ring of quotients (Q)A. But the proof gave no hint of how to calculate the general (c)A's, nor the particular (Q)A's. In the present paper, we give an explicit formula (and separate proof of existence) for the (c)A's, under more complicated hypotheses on the category and assuming the c
A
's are essential monomorphisms. We discuss briefly how the formula proves adequate to calculate the (Q)A's in Archimedean f-rings, and some related and necessary constructs in Archimedean l-groups. 相似文献