Polynomial Approximation to Harmonic and Analytic Functions: Generalized Continuity Conditions

On the Degree of Polynomial Approximation to Harmonic and Analytic Functions

Integrated Continuity Conditions and Degree of Approximation by Polynomials or by Bounded Analytic Functions^)

Introduction. In the study of uniform approximation to a function of a complex variable by polynomials or by bounded analytic functions, Lipschitz conditions have proved extremely useful in relating degree of approximation to continuity properties of the functions approximated. Parts of this theory are analogous to the older study (S. Bernstein, D. Jackson, de la Vallee Poussin, Montel) of appr...

Best Approximation in the Mean by Analytic and Harmonic Functions

For n ≥ 2, let Bn denote the unit ball in R, and for p ≥ 1 let L denote the Banach space of p-summable functions on Bn. Let L p h(Bn) denote the subspace of harmonic functions on Bn that are p-summable. When n = 2, we often write D instead of B2, and we let A denote the Bergman space of analytic functions in L. Let ω be a function in L. We are interested in finding the best approximation to ω i...

Harmonic morphisms onto Riemann surfaces and generalized analytic functions

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Polynomial operators for spectral approximation of piecewise analytic functions

We construct a sequence of globally defined polynomial valued operators, using linear combinations of either the coefficients in the orthogonal polynomial expansion of the target function with respect to a very general mass distribution μ or the values of the function at suitable points on [−1, 1], so that the degree of approximation by these operators globally is commensurate with the degree o...