This is the third paper of a series revisiting the Faraday effect. Thequestion of the absolute convergence of the sums over the band indices enteringthe Verdet constant is considered. In general, sum rules and traces per unitvolume play an important role in solid state physics, and they give rise tocertain convergence problems widely ignored by physicists. We give a completeanswer in the case of smooth potentials and formulate an open problem relatedto less regular perturbations.
展开▼
