| Popis: |
Turan pointed out the importance of studying the location of the zeros of a polynomial in terms of the coefficients of an orthogonal expansion. He himself obtained numerous results for the Hermite expansion. Later Specht showed in a series of papers that analogous theorems hold for any expansion with respect to a system of polynomials orthogonal on the real line. His work stimulated various further studies. We give a survey on this topic with special emphasis on some results from an unpublished manuscript of Specht and new contributions by the author. |
