The index of a pair of pure states and the interacting integer quantum Hall effect

Sven Bachmann, Jacob Shapiro, Clément Tauber

We introduce the index $\mathcal{N}({\omega }_1,{\omega }_2)$ of a pair of pure states on a unital C*-algebra, which is a generalization of the notion of the index of a pair of projections on a Hi…