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21.
This is a study of the completeness properties of the space C
ps
(X) of continuous real-valued functions on a Tychonoff space X, where the function space has the pseudocompact-open topology. The properties range from complete metrizability to the Baire
space property.
Dedicated to Professor Robert A. McCoy 相似文献
22.
The notion of an alternatingly hyperexpansive operator on a Hilbert space is generalized to that of an alternatingly hyperexpansive operator tuple, which necessitates exploring the theory of absolutely monotone functions as defined on the m-fold product N
m of the semi-group N of non-negative integers and as defined on semi-open cubes in the m-dimensional real Euclidean space R
m. The multi-variable Laplace transform and the Stieltjes Moment Problem make a natural appearance in the development of the relevant theory, which also highlights the close connections of alternatingly hyperexpansive operator tuples with completely hyperexpansive and subnormal ones. In particular, if T is subnormal and the joint (Taylor) spectrum of its minimal normal extension is contained in a certain subset of the Hermitian space C
m, then T turns out to be alternatingly hyperexpansive. In the context of multi-variable weighted shifts, the last assertion can be related to the notion of a Stieltjes Moment Net. The general characterization of an alternatingly hyperexpansive m-variable weighted shift T, however, requires a certain net of (positive) numbers associated with T to be absolutely monotone on N
m and allows for such a T to be non-subnormal. 相似文献
23.
T.别克 《数学物理学报(B辑英文版)》2005,25(4):681-686
1Introduction and PreliminariesThroughout this paper,we consider linear spaces over the complex numbers C.Given alinear space X and integers m and n,let Mm,n(X)=X?Mm,n denote the linear space ofm×n matricesx=?????x.x..m1,1,1.x..xm1,n,n?????with entries x… 相似文献
24.
It is shown that an n × n matrix of continuous linear maps from a pro-C^*-algebra A to L(H), which verifies the condition of complete positivity, is of the form [V^*TijФ(·)V]^n i,where Ф is a representation of A on a Hilbert space K, V is a bounded linear operator from H to K, and j=1,[Tij]^n i,j=1 is a positive element in the C^*-algebra of all n×n matrices over the commutant of Ф(A) in L(K). This generalizes a result of C. Y.Suen in Proc. Amer. Math. Soc., 112(3), 1991, 709-712. Also, a covariant version of this construction is given. 相似文献
25.
In this paper, we show that the hyponormal Toeplitz operator Tφ with trigonometric polynomial symbol φ is either normal or completely non-normal. Moreover, if Tφ is non-normal, then Tφ has a dense set of cyclic vectors. Some general conditions are also considered. 相似文献
26.
27.
讨论了小球在杆上任一点的碰撞问题,并指出《大学物理》2006年第5期《小球与均质自由杆的碰撞》一文中"完全非弹性碰撞后两物体不一定粘在一起共同运动"的说法是错误的. 相似文献
28.
V. P. Spiridonov 《Theoretical and Mathematical Physics》2007,150(2):266-277
We consider an elliptic analogue of the Gauss hypergeometric function and two of its multivariate generalizations. We describe
their relation to elliptic beta integrals, the exceptional Weyl group E7, the elliptic hypergeometric equation, and Calogero-Sutherland-type models.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 150, No. 2, pp. 311–324, February, 2007. 相似文献
29.
Torben Maack Bisgaard 《Czechoslovak Mathematical Journal》2002,52(1):155-196
We characterize finitely generated abelian semigroups such that every completely positive definite function (a function all of whose shifts are positive definite) is an integral of nonnegative miltiplicative real-valued functions (called nonnegative characters). 相似文献
30.
Hausdorff momentum problem and its relations to spectral theorem for bounded Hilbert space operators are treated. A generalization for some ordered algebras is shown, where projections are replaced by idempotents. 相似文献