We present a general approach to obtain direct and inverse results for approximation in Hölder norms. This approach is used to obtain a collection of new results related with estimates of the best polynomial approximation and with the approximation by linear operators of non-periodic functions in Hölder norms.
A universality theorem for ratios of random characteristic polynomials Original Research Article Pages 803-814 Stolz angle limit of a certain class of self-mappings of the unit disk Original Research Article Pages 815-822 A generalization of the Riesz–Fischer theorem and linear summability methods Original Research Article Pages 841-853
We improve the class of indices for which normality takes place in a Nikishin system and apply this in Hermite-Padé approximation of such systems of functions.
For a given θ ∈ (a, b), we investigate the question whether there exists a positive quadrature formula with maximal degree of precision which has the prescribed abscissa θ plus possibly a and/or b, the endpoints of the interval of integration. This study relies on recent results on the location of roots of quasi-orthogonal polynomials. The above positive… (More)
moments in four numerical simulations of the 3D Navier-Stokes equations. 2008: Linear and nonlinear model large-eddy simulations of a plane jet.