## Séminaire de Physique Théorique

**Spinoptics in a curved spacetime**

Valery Frolov (University of Alberta)

Thursday 11 October 2012 14:00 - Tours - Salle 1180 (Bât E2)

**Résumé :**

In this talk we discuss how polarization of photons affects their motion in a gravitational field created by a rotating massive compact object. We briefly discuss gravito-electromagnetism analogy and demonstrate that spinoptical effects in many aspects are similar to the Strern-Gerlach effect. We use (3+1)-form of the Maxwell equations to derive a master equation for the propagation of monochromatic electromagnetic waves with a given helicity. We first analyze its solutions in the high frequency approximation using the `standard' geometrical optics approach. After that we demonstrate how this `standard' approach should be modified in order to include the effect of the helicity of photons on their motion. Such an improved approach reproduces the standard results of the geometrical optics at short distances. However, it modifies the asymptotic behavior of the circularly polarized beams in the late-time regime. We demonstrate that the corresponding equations for the circularly polarized beam can be effectively obtained by modification of the background geometry by including a small frequency dependent factor. Applications of this formalism to the propagation of the circular polarized photons in the Kerr spacetime are discussed.

**Liens :**