Induced Scattering of Fast Radio Bursts in Magnetar Magnetospheres

TL;DR

This paper studies how induced scattering affects fast radio bursts in magnetar environments, revealing conditions for their escape and diversity, through kinetic theory and simulations.

Contribution

It provides a detailed analysis of induced scattering in magnetar magnetospheres, combining kinetic theory with Particle-in-Cell simulations to explain FRB propagation.

Findings

Scattering is suppressed but still enters linear growth stage in magnetar fields.

Full scattering occurs above a critical plasma density, affecting FRB escape.

Below the critical density, scattering saturates, allowing FRBs to escape.

Abstract

We investigate induced Compton/Brillouin scattering of electromagnetic waves in magnetized electron and positron pair plasma by verifying kinetic theory with Particle-in-Cell simulations. Applying this to fast radio bursts (FRBs) in magnetar magnetospheres, we find that the scattering--although suppressed by the magnetic field--inevitably enters the linear growth stage. The subsequent evolution bifurcates: full scattering occurs when the density exceeds a critical value, whereas below it the scattering saturates and the FRB can escape. This eases the tension with observations of compact emission regions and may explain the observed diversity, including the presence or absence of FRBs associated with X-ray bursts.