Speaker
Description
Highly magnetized neutron stars have quantum refraction effects on pulsar emission due to the non-
linearity of the quantum electrodynamics (QED) action. In this context, we investigate the strong-field
QED effects on the following properties in pulsar emission: (i) the propagation and polarization
vectors, (ii) the polarization states. With regard to (i), we determine the leading-order corrections to
the vectors due to quantum refraction via perturbation analysis. In addition, the QED effects on the
orthogonality between the vectors and the Faraday rotation angle are determined. With regard to (ii),
we solve a system of evolution equations of the polarization states, where the birefringent vector, in
which the QED effects are encoded, combined with the frequency of emission, acts on the Stokes
vector. At a fixed frequency of emission, depending on the magnitude of the birefringent vector, the
evolution of the polarization states largely exhibits three different patterns: monotonic, or half-
oscillatory, or highly oscillatory behaviours. For some practical examples of rotation-powered pulsars,
these features are shown by fully numerical solutions of the evolution equations, and also understood
and confirmed by means of approximate analytical solutions.
[1] Kim D.-H., Kim C. M., Kim S. P. (2024), Monthly Notices of the Royal Astronomical Society, 531, 2148
[2] Kim D.-H., Kim C. M., Kim S. P. (2024), arXiv:2406.05752
