Interpolation linéaire approchée des fonctions bornées définies sur un ensemble de Sidon
Nonlinear Approximation Theory on Compact Groups.
On a Problem of Best Uniform Approximation and a Polynomial Inequality of Visser
In this paper, a generalization of a result on the uniform best approximation of α cos nx + β sin nx by trigonometric polynomials of degree less than n is considered and its relationship with a well-known polynomial inequality of C. Visser is indicated.
On approximation of functions by generalized Abel--Poisson operators.
On Besov-Hardy-Sobolev spaces of analytic functions in the unit disc
On convergence of greedy approximations for the trigonometric system.
On converse theorems of trigonometric approximation in weighted variable exponent Lebesgue spaces.
On counterexamples in multivariate approximation
On equivalence question between the Ditzian-Totik modulus of smoothness and an usual periodic modulus of smoothness.
On fractional derivatives
On Jackson type inequality in Orlicz classes.
It is shown that Jackson type inequality fails in the Orlicz classes φ(L) if φ(x) differs essentially from a power function of any order.
On Representations of Algebraic Polynomials by Superpositions of Plane Waves
* The author was supported by NSF Grant No. DMS 9706883.Let P be a bi-variate algebraic polynomial of degree n with the real senior part, and Y = {yj }1,n an n-element collection of pairwise noncolinear unit vectors on the real plane. It is proved that there exists a rigid rotation Y^φ of Y by an angle φ = φ(P, Y ) ∈ [0, π/n] such that P equals the sum of n plane wave polynomials, that propagate in the directions ∈ Y^φ .
On the approximation of function by Robel matrix
On the comparison of trigonometric convolution operators with their discrete analogues for Riemann integrable functions.
On the degree of approximation by Gauss Weierstrass integrals.
On the Degree of Approximation by the Operators of de la Vallée Poussin.
On the degree of strong approximation of continuous functions by special matrix.
On the degree of strong approximation of integrable functions in Stepanov sense
Considering the class of almost periodic functions integrable in the Stepanov sense we extend and generalize certain results of the first author, as well as of L. Leindler and P. Chandra.
On the method of approximation by families of linear polynomial operators.
On the rate of pointwise summability of Fourier series.