Nearly invariant brangesian subspaces

This article describes Hilbert spaces contractively contained in certain reproducing kernel Hilbert spaces of analytic functions on the open unit disc which are nearly invariant under division by an inner function. We extend Hitt’s theorem on nearly invariant subspaces of the backward shift operator on $H^2(\text{bb}D)$ as well as its many generalizations to the setting of de Branges spaces.