Certain invariant subspaces for operators with rich eigenvalues (Q808402)

The material in this paper was presented at ICM '86, Berkeley. For an operator \(T\in B(H)\), H a Hilbert space, \(f\in H\), let [f] be the invariant subspace under T generated by f. The author first characterized [f] in H and in terms of a sequence of distinct points in a connected open region \(\Omega\). Here the spectrum of a restriction on T was studied, hence obtaining information on infinite dimensional cyclic invariant subspaces under \(T^*\). For some reason there are a number of misprints, such as the sign \(\epsilon\) missing in several places.