Stas Kupin Spectral properties of Jacobi matrices and sum rules of special form (3874K, PDF) ABSTRACT. In this article, we relate the properties of elements of a Jacobi matrix from certain class to the properties of its spectral measure. The main tools we use are the so-called sum rules originally suggested by Case. As a corollary of the main theorem, we obtain a direct counterpart of a result by Molchanov-Novitskii-Vainberg for ``continuous'' Schr\"odinger operator.