Operator-valued Jacobi parameters and examples of operator-valued distributions

Abstract

In the setting of distributions taking values in a C⁎-algebra B, we define generalized Jacobi parameters and study distributions they generate. These include numerous known examples and one new family, of B-valued free binomial distributions, for which we are able to compute free convolution powers. Moreover, we develop a convenient combinatorial method for calculating the joint distributions of B-free random variables with Jacobi parameters, utilizing two-color non-crossing partitions. This leads to several new explicit examples of free convolution computations in the operator-valued setting. Additionally, we obtain a counting algorithm for the number of two-color non-crossing pairings of relative finite depth, using only free probabilistic techniques. Finally, we show that the class of distributions with Jacobi parameters is not closed under free convolution.