Emission Mechanisms of Fast Radio Bursts

TL;DR

This paper reviews the physics of coherent emission mechanisms for fast radio bursts, emphasizing magnetar flares as likely sources and discussing non-linear effects that limit radiation power.

Contribution

It provides a comprehensive overview of proposed emission mechanisms for FRBs, highlighting the role of magnetar flares and non-linear effects in shaping observed signals.

Findings

Curvature emission of bunches as a plausible mechanism

Synchrotron maser emission relevance

Magnetar flares as promising FRB sources

Abstract

Fast radio bursts (FRBs) are recently discovered mysterious single pulses of radio emission, mostly coming from cosmological distances ($\sim 1$ Gpc). Their short duration, $\sim 1$ ms, and large luminosity evidence coherent emission. I review the basic physics of coherent emission mechanisms proposed for FRBs. In particular, I discuss the curvature emission of bunches, the synchrotron maser, and the emission of radio waves by variable currents in the course of magnetic reconnection. Special attention is paid to magnetar flares as the most promising sources of FRBs. Non-linear effects are outlined that could place bounds on the power of the outgoing radiation.