Kragujevac J. Math. 26 (2004) 39-48.

S-ORTHOGONALITY ON THE SEMICIRCLE

Marija Stanic

University of Kragujevac, Faculty of Science, Department of Mathematics and Informatics, P. O. Box 60, 34000 Kragujevac, Serbia
(e-mails: stanicm@ptt.yu,  stanicm@kg.ac.yu)

Abstract. In this paper s-orthogonal polynomials on the semicircle are considered. Generalizing the previous works of Gautschi, Milovanovic and Landau [5, 4, 8, 7, 9, 3] we transfer concept of s-orthogonality (see [6, 10]) to the unit semicircle in the complex plane, with respect to the complex-valued inner product

(f, g)=ò0pf(eiq)g(eiq)w(eiqdq.

A detailed study is made of the s-orthogonal polynomials on the semicircle in the case of the Chebyshev weight of the first kind.