Oral Presentation

Induced Compton scattering in magnetized electron and positron pair plasma and application to Fast Radio Bursts

Author(s): Rei Nishiura

Presenter: Rei Nishiura (Kyoto University)

Nonlinear interaction between electromagnetic waves and plasma is essential in various fields, including astrophysical contexts and laser nuclear fusion. Recently, this interaction has gained attention in fast radio bursts (FRBs). This study focuses on induced Compton scattering, a kind of parametric decay instability, in magnetized electron and positron plasma, especially targeting within the magnetosphere of magnetars. We derive the linear growth rate of induced Compton scattering, considering the magnetized electron and positron plasma effects for the first time. Our analysis reveals that the linear growth rate significantly varies depending on the polarization direction of the incident electromagnetic wave and plasma density. For waves polarized parallel to the magnetic field, the growth rate corresponds to the non-magnetized case. However, Debye screening is critical in waves polarized perpendicular to the magnetic field. We identify two density fluctuation modes: the charged mode, which is influenced by Debye screening, and the neutral mode, which is not. These findings provide essential insights into FRB propagation in a magnetar magnetosphere, suggesting significant suppression of induced Compton scattering growth rates due to magnetic fields and Debye screening, even in high plasma density regions.