Multivariate polynomials are a main tool in approximation. The book begins with an introduction to the general theory by presenting the most important facts on multivariate interpolation, quadrature, orthogonal projections and their summation, all treated under a constructive view, and embedded in the theory of positive linear operators. On this background, the book gives the first comprehensive introduction to the recently developped theory of generalized hyperinterpolation. As an application, the book gives a quick introduction to tomography. Several parts of the book are based on rotation principles, which are presented in the beginning of the book, together with all other basic facts needed.

New access to Appell polynomials via an elementary biorthonormal system defined by the reproducing kernel of spherical harmonics Comprehensive introduction to generalized hyperinterpolation Contains introduction to tomography

Autorentext
Manfred Reimer arbeitete nach der Promotion an der Universität Tübingen zunächst als Wissenschaftlicher Assistent am Mathematischen Institut Tübingen. 1966 folgt die Habilitation, ebenfalls in Tübingen. 1967/68 arbeitete Professor Reimer als Research Assistant Professor an der University of Maryland. 1969 wechselte er als ordentlicher Professor an die Universität Dortmund, wo er an der Gründung und dem Aufbau des Mathematischen Instituts mitwirkte, forschte und lehrte. Seit 1999 ist er emeritiert, aber weiterhin wissenschaftlich tätig.

Inhalt
1 Basic Principles and Facts.- 2 Gegenbauer Polynomials.- 3 Multivariate Polynomials.- 4 Polynomials on Sphere and Ball.- 5 Approximation Methods.- 6 Approximation on the Sphere.- 7 Approximation on the Ball.- 8 Tomography.- A Legendre Basis.- B Zeros of the Kernel Function.- C NewmanShapiro Operators.- D Reconstruction.- E Solutions.