Total positivity and the exact n-width of certain sets in L¹

Charles Anthony Micchelli and Allan Pinkus

Vol. 71 (1977), No. 2, 499–515

DOI: 10.2140/pjm.1977.71.499

Abstract

In this paper we obtain the exact value of the L¹ n-width, both in the sense of Kolmogorov and Gel’fand, and characterize optimal subspaces for the set

under certain total positivity assumptions on

A matrix analogue is also described.

Mathematical Subject Classification 2000

Primary: 41A45

Milestones

Received: 28 May 1976

Published: 1 August 1977