New reciprocity theorems for chiral, nonactive, and bi-isotropic media

Two generalized reciprocity theorems for homogeneous bi-isotropic media are presented that do not invoke a complementary space. One of them is eminently crosspolarized involving real sources and fields, while the other is a generalization of the Lorentz theorem and is therefore eminently copolarized, invoking generalized sources or fields. These theorems constitute the foundation for new variational expressions leading to a reaction-type development with capabilities to handle biisotropic/nonactive/chiral/isotropic materials