Abstract and Applied Analysis 
Volume 2006 (2006), Article ID 42305, 17 pages
doi:10.1155/AAA/2006/42305

Norming points and unique minimality of orthogonal projections

Boris Shekhtman and Lesław Skrzypek

 Department of Mathematics, University of South Florida, 4202 E. Fowler Avenue, PHY 114, Tampa 33620-5700, FL, USA
Received 5 March 2005; Accepted 6 April 2005

Abstract

We study the norming points and norming functionals of symmetric operators on Lp spaces for p=2m or p=2m/(2m−1). We prove some general result relating uniqueness of minimal projection to the set of norming functionals. As a main application, we obtain that the Fourier projection onto span [1,sin⁡x,cos⁡x] is a unique minimal projection in Lp.