Many astrophysical phenomena depend on the underlying dynamics of magnetic fields. The observations of accretion disks and their jets, stellar coronae, and the solar corona are all best explained by models where magnetic fields play a central role. Understanding these phenomena requires studying the basic physics of magnetic field generation, magnetic energy transfer into radiating particles, a...

Context. Faraday rotation measurements of extragalactic radio sources during coronal occultation allow assessment of both the electron density distribution and the three-dimensional magnetic field topology in the outer solar corona. Aims. We simulate the three-dimensional structure of both the coronal magnetic field and the electron density distribution in order to reproduce the excess Faraday ...

Using high frequency (12-22 GHz) VLBA observations we confirm the existence of a Faraday rotation measure gradient of ∼500 rad m −2 mas −1 transverse to the jet axis in the quasar 3C 273. The gradient is seen in two epochs spaced roughly six months apart. This stable transverse rotation measure gradient is expected if a helical magnetic field wraps around the jet. The overall order to the magne...

I discuss the transfer of polarized synchrotron radiation in relativistic jets. I argue that the main mechanism responsible for the circular polarization properties of compact synchrotron sources is likely to be Faraday conversion and that, contrary to common expectation, a significant rate of Faraday rotation does not necessarily imply strong depolarization. The long-term persistence of the si...

Modelling of deep VLA images of the jets in FR I radio galaxies has allowed us to derive their three-dimensional distributions of velocity, emissivity and magnetic-field structure on kiloparsec scales. By combining our models of jet kinematics with measurements of the external pressure and density derived from Chandra observations, we can also determine the jet dynamics via a conservation-law a...

Resonant nonlinear magneto-optical rotation (NMOR) [1, 2] has been the subject of extensive theoretical and experimental studies because it provides a very sensitive way to measure magnetic fields (see, e.g., Ref. [3]). While NMOR experiments are usually carried out with vapor samples of moderate optical thickness (no more than ∼ 2 absorption lengths), the intense research of recent years on el...

Studies of the nonlinear Faraday effect (rotation of the plane of polarization in a longitudinal magnetic field) on resonance atomic transitions have been reported in a number of theoretical and experimental papers [1-9]. The nonlinear effect manifests itself at moderate laser intensities in the absence of atomic collisions. It leads to narrow peaks in the magnetic field dependence of Faraday r...

This paper is intended to investigate the relation between electrodynamics in anisotropic material media and its analogous formulation in an spacetime, with non-null Riemann curvature tensor. After discussing the electromagnetism via chiral differential forms, we point out the optical activity of a given material medium, closely related to topological spin, and the Faraday rotation, associated ...

The Faraday effect is an extremely useful probe of magnetization dynamics on an ultrafast scale. However, the measured Faraday rotation is difficult to interpret in birefringent media. We investigate the link between magnetization and Faraday rotation by solving Maxwell’s equations in a magnetically ordered, birefringent material. We find that the Faraday rotation can depend nonlinearly on the ...