Results 11 to 20 of about 9,593 (216)
Approximation by positive operators
Linear Algebra and its Applications, 1992 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Bhatia, Rajendra, Kittaneh, Fuad
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Iteration of positive approximation operators
Journal of Approximation Theory, 1970 AbstractWe present an analysis of the limit behavior of the k(n)-th iterates of positive linear approximation operators Ln, as n and k(n) tend to infinity. For various classes of operators the limit semigroup is explicitly identified. Two applications of the results are given: (a) identification of functions f satisfying Ln f ⩾ f for all n, for a ...
Karlin, S, Ziegler, Z
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Unitary approximation of positive operators
Illinois Journal of Mathematics, 1980 Of concern are some operators inequalities arising in quantum chemistry. Let $A$ be a positive operator on a Hilbert space $\mathcal{H}$. We consider the minimization of $||U-A||_{p}$ as $U$ ranges over the unitary operators in $\mathcal{H}$ and prove that in most cases the minimum is attained when $U$ is the identity operator. The norms considered are
Aiken, John G. +2 more
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On Ritz approximations for positive definite operators I (theory) [PDF]
Linear Algebra and its Applications, 2006 We give new lower bounds on the Rayleigh--Ritz approximations of a part of the spectrum of an elliptic operator. Furthermore, we present bounds for the accompanying Ritz vectors. The bounds include a form of a relative gap between the Ritz values and the rest of the spectrum of the operator.
Grubišić, Luka, Veselić, Krešimir
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Approximations of positive operators and continuity of the spectral radius II
Mathematische Zeitschrift, 1992 AbstractWe prove estimates on the speed of convergence of the ‘peripheral eigenvalues’ (and principal eigenvectors) of a sequence Tn of positive operators on a Banach lattice E to the peripheral eigenvalues of its limit operator T on E which is positive, irreducible and such that the spectral radius r(T) of T is a Riesz point of the spectrum of T (that
Caselles, V., Aràndiga, F.
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Approximation by positive operators in the space \(C^{(p)}([a,b])\)
Journal of Numerical Analysis and Approximation Theory, 1989 Not available.
Francesco Altomare, Ioan Raşa
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The Θ-transformation of certain positive linear operators
International Journal of Mathematics and Mathematical Sciences, 1996 The intention of this paper is to describe a construction method for a new sequence of linear positive operators, which enables us to get a pointwise order of approximation regarding the polynomial summator operators which have best properties of ...
Aleandru Lupaş, Detlef H. Mache
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Statistical rates in approximation by positive linear operators [PDF]
Miskolc Mathematical Notes, 2011 This study is the continuation of our former work [O. Duman and E. Erkus,, Comput. Math. Appl. 52 (2006) 967-974] in which we obtained a statistical Korovkin-type approximation theorem for a sequence of positive linear operators defined on the space of all real-valued continuous and 2 pi periodic functions on the real m-dimensional space. In this paper,
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Certain approximation properties of Brenke polynomials using Jakimovski–Leviatan operators
Journal of Inequalities and Applications, 2021 In this article, we establish the approximation by Durrmeyer type Jakimovski–Leviatan operators involving the Brenke type polynomials. The positive linear operators are constructed for the Brenke polynomials, and thus approximation properties for these ...
Shahid Ahmad Wani +2 more
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Statistical approximation by positive linear operators [PDF]
Studia Mathematica, 2004 The sequences of some classical approximation operators tend to converge to the values of the function they approximate, except perhaps at points of discontinuity, where in several cases such sequences do not converge to any value. Statistical convergence, which is a regular non-matrix summability method, has revealed effective to correct the lack of ...
Duman, O., Orhan, C.
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