A C*-Algebraic Framework for Explaining Higher-Order Bulk-Boundary Correspondences in Topological Insulators and Superconductors

This paper introduces a novel C*-algebraic framework to rigorously explain and classify higher-order bulk-boundary correspondences, a phenomenon in topological insulators and superconductors where the topological properties of the material's bulk predict the existence of protected electronic states at corners, hinges, or other lower-dimensional boundaries.