Electromagnetic helicity wavelets: a model for quasar engines?
  The complex distance function $\zeta$, which plays a prominent role in the
definition of scalar (acoustic) wavelets, is found to determine a complex
extension of the spherical coordinate system that is ideally suited for the
construction of highly focused electromagnetic beams with helicities conforming
to the oblate spheroidal geometry of $\zeta$. This is used to build a basis of
electromagnetic wavelets $F^m$ radiated or absorbed by the branch disk $D$ of
$\zeta$. $F^m$ has integer angular momentum $m$ around the z axis and definite
spheroidal helicity. We use a regularization method to compute its singular
charge-current density and show that the total charge vanishes. Hence $F^m$ is
due solely to electric and magnetic polarization currents. $D$ acts as a
magnetic dipole antenna, and its axis as a coupled electric dipole antenna. We
propose this as an idealized electromagnetic model for quasars (in flat
spacetime, without gravity), with $D$ representing the accretion disk and the
vortex singularities along its axis representing the jets. In the regularized
version, the accretion disk is represented by a solid flat oblate spheroid and
the jets by two solid narrow semi-hyperboloids.
