Surveys in Approximation Theory (SAT)

Surveys in Approximation Theory, 1 (2005), 1-45.

Density in Approximation Theory

Allan Pinkus

Abstract. Approximation theory is concerned with the ability to approximate functions by simpler and more easily calculated functions. The first question we ask in approximation theory concerns the possibility of approximation. Is the given family of functions from which we plan to approximate dense in the set of functions we wish to approximate? In this work, we survey some of the main density results and density methods.

E-print: arXiv:0501328

Published: 14 January 2005.

PDF file
Some minor corrections of this paper are here.

Allan Pinkus
Department of Mathematics
Technion
Haifa, 32000
Israel
E-mail: pinkus@tx.technion.ac.il
Webpage: http://www.math.technion.ac.il/~pinkus