Results 291 to 300 of about 1,373,330 (305)
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Ukrainian Mathematical Journal, 1990
New properties of operator connections and means are established. Specifically, representations of an arbitrary connection by means of a concave representing function, an estimate of the norm of a connection in a von Neumann-Schatten ideal, a relation between operator means and convolutions onto operator domains are obtained.
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New properties of operator connections and means are established. Specifically, representations of an arbitrary connection by means of a concave representing function, an estimate of the norm of a connection in a von Neumann-Schatten ideal, a relation between operator means and convolutions onto operator domains are obtained.
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1954
It is evident that the property “variation-diminishing” is transitive.*) Making use of this fact, we shall derive a rather general class of variation-diminishing linear transformations by means of an iterative process. It will then be shown how the matrix of a transformation of this class may be calculated explicitly, and as a by-product of these ...
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It is evident that the property “variation-diminishing” is transitive.*) Making use of this fact, we shall derive a rather general class of variation-diminishing linear transformations by means of an iterative process. It will then be shown how the matrix of a transformation of this class may be calculated explicitly, and as a by-product of these ...
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The Spectrum of Weighted Mean Operators
Canadian Mathematical Bulletin, 1987AbstractRecently J. B. Reade determined the spectrum of C, the Cesaro matrix of order 1, considered as an operator on c0, the space of null sequences. Previously F. P. A. Cass and the author had determined the spectra for a large class of weighted mean operators on c, the space of convergent sequences.
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2010
It is a consequence of a well-known theorem of Godement [1952] that if X is a two-point homogeneous space and u a harmonic function on X, i.e., Lu = 0, then u has the mean-value ...
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It is a consequence of a well-known theorem of Godement [1952] that if X is a two-point homogeneous space and u a harmonic function on X, i.e., Lu = 0, then u has the mean-value ...
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Operator means and positivity of block operators
Mathematische Zeitschrift, 2017The aim of this paper is to find some sufficient conditions for positivity of block matrices of positive operators. It is shown that for positive operators A, B, C and for every non-negative operator monotone function f on $$ (0,\infty )$$
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Operator Means and the Relative Operator Entropy
1992The notion of operator monotone functions was introduced by Lowner and that of operator concave functions by Kraus who is his student. Operator means were introduced by Ando and the general theory of them was established by Kubo and Ando himself. By their theory, a nonnegative operator monotone function is now considered as a variation of an operator ...
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