Hyperinvariant subspaces of \(C_0\)-operators over a multiply connected region (Q1974673)

Let \(T\) be an operator of class \(C_0\) over a multiply connected domain and let \(T'\) be its Jordan model. The paper shows that the lattice of hyperinvariant subspaces of \(T'\) can be identified with a retract of the lattice of hyperinvariant subspaces of \(T\). Consequently, the Jordan model has the smallest lattice of hyperinvariant subspaces in a given quasisimilarity class.