Ivan Kuscer, Orthogonality and All That

摘要

In memoriam Ivan Kuscer, born Vienna, June 17, 1918, died Ljubljana January 31, 2000. My close association with Ivan began in 1963 and continued up to 1999. In this article I describe some of our itneractions, both in physics and in our personal lives. One focal point is Ivan's classic article (with McCormick and Summerfield) on the partial-range orthogonality of Case's singular eigenfunctions. Some of the work inspired by this article is described. Also, Ivan's love-hate relationship with mathematics is discussed insome detail.