The small degree of circular polarisation observed in some synchrotron sources has a frequency dependence that is not consistent with simple predictions based on the intrinsic circular polarisation of synchrotron emission. The suggestion is explored that the circular polarisation arises as a propagation effect within the source. The physical basis of this alternative mechanism is the fact that ...

A key structure in so-called metamaterial mediums is the elementary split-ring resonator. We consider in this paper the lowfrequency electromagnetic scattering by a split-ring particle modelled as a perfectly conducting wire ring, furnished with a narrow gap, and derive analytical solutions for the electric and magnetic dipole moments for different kinds of incidence and polarisation in the qua...

The string-inspired technique is used for a first calculation of the one-loop axialvector vacuum polarisation in a general constant electromagnetic field. A compact result is reached for the difference between this tensor and the corresponding vector vacuum polarisation. This result is confirmed by a Feynman diagram calculation. Its physical relevance is briefly discussed.

We solve the wave equation for the electromagnetic field tensors associated with the CMBR photons in a universe with scalar metric perturbations. We show that the coupling of the electromagnetic fields with the curvature associated with the scalar perturbations gives rise to an optical rotation of the microwave background photons. The magnitude of the gravitationally generated V-Stokes paramete...

A one dimensional, computational model for the propagation of ultra low frequency (ULF; 1–100 mHz) wave fields from the Earth’s magnetosphere through the ionosphere, atmosphere and into the ground is presented. The model is formulated to include solutions for high latitudes where the Earth’s magnetic field, (B0), is near vertical and for oblique magnetic fields applicable at lower latitudes. Th...

This paper will highlight the contributions of Heinrich Hertz by his sensational experiments, carried out in Karlsruhe, Germany, in the years 1885 to 1889, to the first radio communication experiments. Heinrich Hertz developed for the first time a complete pulsed radar, an indoor communication link and a material test set, all in one. The basic system components had been the spark gap oscillato...

Abstract. We have developed methods for tracing rays and performing radiative transfer through a magnetoactive plasma in a general relativistic environment. The two electromagnetic plasma modes propagate differently due to a combination of dispersive and gravitational effects. We have found that, when given an appropriate environment surrounding the central black hole, it is indeed possible to ...

We consider the representations of optical Dirac equation, especially ones where Hamiltonian is purely real-valued. This equivalent, for Maxwell's equations, to Majorana representation massless (Weyl) equation. draw analogies between Dirac, chiral and derive two new representations. Just as are related spin helicity states, these equation associated with linear polarisation light. provides a me...