9 research outputs found
Multi-operator colligations and multivariate characteristic functions
In the spectral theory of non-self-adjoint operators there is a well-known
operation of product of operator colligations. Many similar operations appear
in the theory of infinite-dimensional groups as multiplications of double
cosets. We construct characteristic functions for such double cosets and get
semigroups of matrix-valued functions in matrix balls.Comment: 15p