The Singularly Continuous Spectrum and Non-Closed Invariant Subspaces
The Singularly Continuous Spectrum and Non-Closed Invariant Subspaces
Let A be a bounded self-adjoint operator on a separable Hilbert space โ and โ0 โ โ a closed invariant subspace of A. Assuming that โ0 is of codimension 1, we study the variation of the invariant subspace โ0 under bounded self-adjoint perturbations V of A that are off-diagonal with โฆ