Results 1 to 10 of about 8,919 (268)

Two sharp inequalities for operators in a Hilbert space

Researches in Mathematics, 2022
In this paper we obtained generalisations of the L. V. Taikov’s and N. Ainulloev’s sharp inequalities, which estimate a norm of function's first-order derivative (L. V. Taikov) and a norm of function's second-order derivative (N.
N.O. Kriachko
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Coefficients of multiple Fourier-Haar series and variational modulus of continuity

Қарағанды университетінің хабаршысы. Математика сериясы, 2023
In this paper, we introduce the concept of a variational modulus of continuity for functions of several variables, give an estimate for the sum of the coefficients of a multiple Fourier-Haar series in terms of the variational modulus of continuity, and ...
T.B. Akhazhanov, N.А. Bokayev, D.T. Matin, T. Aktosun   +3 more
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On the nonsymmetric approximation of continuous functions in the integral metric

Researches in Mathematics, 2020
In the paper, an exact estimate of the best nonsymmetric approximation in the integral metric by the constants of continuous functions that belong to the classes $H^\omega[a,b]$ is proved.
V.F. Babenko, O.V. Polyakov
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New Construction and New Error Bounds for (0, 2, 4) Lacunary Interpolation By Six Degree Spline [PDF]

Al-Rafidain Journal of Computer Sciences and Mathematics, 2011
The object of this paper obtains the existence, uniqueness and upper bounds for errors of six degree splines interpolating the lacunary data (0, 2, 4). We also show that the changes of  the boundary conditions and the class of spline functions has a main
Karwan Jwamer, Ridha Karem
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Luzin's condition (N) and modulus of continuity [PDF]

Advances in Calculus of Variations, 2014
Abstract In this paper, we establish Luzin's condition (N) for mappings in certain Sobolev–Orlicz spaces with certain moduli of continuity. Further, given a mapping in these Sobolev–Orlicz spaces, we give bounds on the size of the exceptional set where Luzin's condition (N) may fail.
Malý, Jan, Zürcher, Thomas, Koskela, Pekka   +2 more
openaire   +3 more sources

Approximation on a class of Phillips operators generated by q-analogue

Journal of Inequalities and Applications, 2020
The main purpose of this article is to introduce a new generalization of q-Phillips operators generated by Dunkl exponential function. We establish some approximation results for these operators. We also determine the order of approximation, and the rate
Abdullah Alotaibi
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Approximation by bivariate Chlodowsky type Szász–Durrmeyer operators and associated GBS operators on weighted spaces

Journal of Inequalities and Applications, 2022
In this article, we consider a bivariate Chlodowsky type Szász–Durrmeyer operators on weighted spaces. We obtain the rate of approximation in connection with the partial and complete modulus of continuity and also for the elements of the Lipschitz type ...
Reşat Aslan, M. Mursaleen
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Parametric Extension of a Certain Family of Summation-Integral Type Operators

Cumhuriyet Science Journal, 2023
In this paper, we introduce a parametric extension of a certain family of summation-integral type operators on the interval [0,∞). Firstly, we obtain test functions and central moments. Secondly, we investigate weighted approximation properties for these
İsmet Yüksel, Nadire Fulda Odabaşı
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Modulus of continuity of operator functions [PDF]

St. Petersburg Mathematical Journal, 2009
Summary: Let \(A\) and \(B\) be bounded selfadjoint operators on a separable Hilbert space, and let \(f\) be a continuous function defined on an interval \( [a,b]\) containing the spectra of \(A\) and \(B\). If \(\omega _f\) denotes the modulus of continuity of \(f\), then \[ \| f(A)-f(B)\| \leq 4\Big[\log\Big(\frac{b-a}{\| A-B\|}+1\Big)+1\Big]^2 \cdot
Farforovskaya, Yu. B., Nikolskaya, L.
openaire   +1 more source

On the Approximation of Periodic Functions in L2 and the Values of the Widths of Certain Classes of Functions

Моделирование и анализ информационных систем, 2015
The sharp Jackson–Stechkin inequalities are received, in which a special module of continuity Ωem(f;t) determined by Steklov’s function is used instead the usual modulus of continuity of mth order ωm(f;t).
K. Tukhliev
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