Measures with finite index of determinacy or a mathematical model for Dr. Jekyll and Mr. Hyde
Christian Berg, Antonio J. Durán · Proceedings of the American Mathematical Society · 1997
In this note measures with finite index of determinacy (i.e. determinate measures μ \mu for which there exists a polynomial p p such that | p | 2 μ \vert p\vert ^{2} \mu is indeterminate) are characterizated in terms of the operator associated to its Jacobi matrix. Using this characterization, we show that such determinate measures with finite index of determinacy (Jekyll) turn out to be indeterminate (Hyde) when considered as matrices of measures.