Avijit K. Ganguly

Faraday effect: A Field theoretical point of view

We analyze the structure of the vacuum polarization tensor in the presence of a background electromagnetic field in a medium. We use various discrete symmetries and crossing symmetry to constrain the form factors obtained for the most general case. From these symmetry arguments, we show why the vacuum polarization tensor has to be even in the background field when there is no background medium. Taking then the background field to be purely magnetic, we evaluate the vacuum polarization to linear order in it. The result shows the phenomenon of Faraday rotation, i.e., the rotation of the plane of polarization of a plane polarized light passing through this background. We find that the usual expression for Faraday rotation, which is derived for a non-degenerate plasma in the non-relativistic approximation, undergoes substantial modification if the background is degenerate and/or relativistic. We give explicit expressions for Faraday rotation in completely degenerate and ultra-relativistic media.

Optical activity from extra dimensions

Optical activity, like Faraday effect, is a rotation of the plane of polarization of propagating light in a medium and can be attributed to different sources with distinct signatures. In this note we discuss the effect of optical activity {\it{in vacuum}} due to Kaluza-Klein scalar field

Absorption of electromagnetic waves in a magnetized medium

\phi

Lorentz symmetry violating low energy dispersion relations from a dimension-five photon scalar mixing operator

, in the presence of an external electro-magnetic field. The astrophysical implication of this effect is indicated. We also point out the possibility of observing the same in laboratory conditions.

Photon and axion oscillation in a magnetized medium: A general treatment

In continuation to our earlier work, in which the structure of the polarization tensor in a medium was analyzed in the presence of a background electromagnetic field, we discuss the absorptive part of the polarization tensor. Using the real time formalism of finite temperature field theory we calculate the absorptive part of the 1-loop polarization tensor in the weak field limit

Effective neutrino photon interaction in a magnetized medium

(eBl{m}^{2}).

Comment on Fermionic and Bosonic Pair-creation in an External Electric Field at Finite Temperature

Estimates of the absorption probability are also made for different physical conditions of the background medium.

Neutrino Photon Interaction in a Magnetized Medium II

Dimension-five photon

Photon Scalar/Pseudoscalar Mixing Dynamics In Magnetized Media

(\gamma )

Signatures Of Scalar Photon Interaction In Astrophysical Situations

scalar