A mechanism for fast radio bursts and their narrow spectra

@misc{beloborodov2026mechanism,
  title = {{A mechanism for fast radio bursts and their narrow spectra}},
  author = {Andrei M. Beloborodov and Ivan Demidov},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.21076},
  eprint = {2609.21076},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.21076},
  note = {CC BY-NC-ND 4.0},
}

TY  - UNPB
TI  - A mechanism for fast radio bursts and their narrow spectra
AU  - Andrei M. Beloborodov
AU  - Ivan Demidov
PY  - 2026
DA  - 2026/09/17
PB  - arXiv
DO  - 10.48550/arxiv.2609.21076
UR  - https://arxiv.org/abs/2609.21076
AB  - We find an emission mechanism for fast radio bursts (FRBs) capable of producing broad and narrow spectra. It operates in magnetar explosions, which launch an electromagnetic pulse from the inner magnetosphere at radii r_0∼ 10^7 cm. Plasma inside the pulse accelerates outward with Lorentz factor Γ(r)≈ r/r_0. Before exiting the magnetosphere at radius r∼ 10^10 cm, the pulse passes through ambient kHz waves that populate the magnetospheres of active magnetars. We show that the waves experience stimulated scattering inside the pulse, with the boost factor Γ^2 converting them into radial GHz radiation. This process exponentially amplifies tiny GHz seeds to extreme luminosities consistent with observed FRBs. The produced GHz burst rides inside the explosion pulse, which helps it escape to distant observers. The FRB duration and energy are controlled by the pulse duration and energy. In a saturated emission regime, the predicted burst contains an ultrastrong microsecond component.
ER  -