title: Null-field radiationless sources.
abstract: It is shown that it is in principle possible to produce combined sources of polarization and magnetization that are not only radiationless but that have any (and sometimes several) of the four microscopic or macroscopic electromagnetic fields exactly zero. The conditions that such a "null-field radiationless source" must satisfy are derived, and examples are given for several cases. The implications for transformation optics and invisibility physics in general are discussed.
authors.forename: Elisa
authors.initials: E
authors.lastname: Hurwitz
authors.forename: Greg
authors.initials: G
authors.lastname: Gbur