On the mean profiles of radio pulsars I: Theory of the propagation   effects
  We study the influence of the propagation effects on the mean profiles of radio pulsars using the Kravtsov-Orlov method of the wave propagation in the inhomogeneous media. This approach allows us firstly to include into consideration the transition from geometrical optics to vacuum propagation, the cyclotron absorption, and the wave refraction simultaneously. In addition, arbitrary non-dipole magnetic field configuration, drift motion of plasma particles, and their realistic energy distribution are taken into account. The one-to-one correspondence between the signs of circular polarization and position angle (p.a.) derivative along the profile for both ordinary and extraordinary waves is predicted. Using the numerical integration we now can model the main profiles of radio pulsars. It is shown that standard S-shape form of the p.a. swing can be realized for small enough pair production multiplicity and large enough bulk plasma Lorentz factor only. It is also shown that the value of p.a. maximum derivative, that is often used for determination the angle between magnetic dipole and rotation axis, depends on the plasma parameters and could differ from the rotation vector model (RVM) prediction. 
V. S. Beskin and A. A. Philippov
astro-ph.HE