Talk detail

Participant	Tsupko, Oleg
Institution	Space Research Institute (IKI) of Russian Academy of Sciences - Profsoyuznaya 84/32 - Moscow - Russia - Russia

Session	BH2	Accepted		Order	Time
Talk	Oral abstract	Title	Gravitational Lensing in presence of Strong Gravitational Fields and Plasma
Co-authors
Abstract	Theory of gravitational lensing is well developed for the light propagation in vacuum in approximation of a weak deflection. We review two ways to expand the consideration of usual gravitational lens theory, which were recently theoretically developed. One way is to go beyond the weak deflection approximation and calculate analytically the positions and magnifications of relativistic images, using the strong deflection limit. Another way is to consider a plasma instead vacuum. In this case the lensing angle depends on the plasma distribution and the photon frequency. The gravitational deflection of light ray even in the homogeneous plasma differs from vacuum (Einstein) angle and depends on the photon frequency. We also obtain analytical formulae for gravitational deflection angle in homogeneous plasma in the strong deflection limit.