Topological approach to Luttinger's theorem and the Fermi surface of a Kondo lattice

A nonperturbative proof of Luttinger's theorem, based on a topological argu ment, is given for Fermi Liquids in arbitrary dimensions. Application to th e Kondo lattice shows that even completely localized spills contribute to t he Fermi sea volume as electrons, whenever the system can be described as a Fermi liquid.