A Measurable Selector in Kadison’s Carpenter’s Theorem

Abstract

AbstractWe show the existence of a measurable selector in Carpenter’s Theorem due to Kadison. This solves a problem posed by Jasper and the first author in an earlier work. As an application we obtain a characterization of all possible spectral functions of shift-invariant subspaces of $L^{2}(\mathbb{R}^{d})$ and Carpenter’s Theorem for type $\text{I}_{\infty }$ von Neumann algebras.