Photon wave functions The fundamental building block of the
theory of photons is the wave function for a single photon. A
detailed study of the properties of a photon wave equation and
its solutions has been made in a recent work that considers both
classical and quantum solutions of the Maxwell equations.
Properties that are expected to be satisfied by a photon wave
function are enumerated and shown to be met by the formalism
provided in the study: Solutions of the Maxwell equations and
photon wave functions, P. J. Mohr, Annals of Physics 325,
607-663 (2010). (Preprint PDF) Excited states of atoms have
attractive properties as a potential source of information on
fundamental constants and tests of theory. It has been shown
that the largest sources of uncertainty of atomic levels, namely
the charge radius of the nucleus and higher-order quantum
electrodynamic effects are greatly diminished in states with
angular momentum 2ħ or greater. These points are discussed and
results of detailed calculations, including