Topic #6 -------------- OP-SF NET -------------- November 14, 1994 ~~~~~~~~~ From: OP-SF Net Editor
Subject: Death of H.L. Krall Harry L. Krall, Professor Emeritus at Pennsylvania State University, died on June 9, 1994. He was born on June 13, 1907. In the late thirties Krall published results about orthogonal polynomials which are eigenfunctions of a fourth order differential equation. Recently this work has been taken up again and significant generalizations have been given by a.o. A.M. Krall, L. Littlejohn and R. Koekoek. In 1949 Krall published, jointly with O. Frink, a paper in Trans. AMS containing the first systematic study of a class of polynomials to which they gave the name of Bessel polynomials and which have remained familiar under this name until now. In the sixties, Krall published some papers on orthogonal polynomials together with I.M. Sheffer. One of these classified orthogonal polynomials in two variables being eigenfunctions of a second order partial differential operator.