Speaker
Description
We propose a mechanism for fast radio bursts (FRBs) based on photon acceleration by relativistic shocks in highly magnetized electron-positron plasmas, as expected in magnetar magnetospheres. Density modulations at the shock front create relativistically moving refractive index perturbations that transform low-frequency electromagnetic precursors into enhanced high-frequency radiation. In magnetized pair plasmas, relativistically moving plasma layers exhibit enhanced reflectivity, while the maximum emission frequency is limited by the electron Larmor frequency. The observed frequencies, durations, and energetics of FRBs are reproduced for magnetic field strengths, spatial scales, and shock Lorentz factors consistent with those expected in magnetar magnetospheres. These results identify photon acceleration by relativistic magnetized shocks as a viable mechanism for FRB formation.