Speaker
Description
Primordial black holes (PBHs) in the asteroid-mass window ($10^{17}-10^{22}$ g) are a well-motivated dark-matter candidate, and Hawking radiation sets constraints based on their evaporation outcomes such as photons, electrons and positrons. In this specific mass range, the Hawking temperatures are high enough to facilitate the generation of electron-positron pairs, which can contribute to the 511 keV annihilation line and impose further constraints on the abundance of PBHs. Accurate predictions therefore require a systematic QED calculation of the electron spectrum from Hawking radiation. In this study, the first-order QED correction to the dissipative part of the electron spectrum in a Schwarzschild black-hole background is derived using the interaction-Hamiltonian formalism. The resulting correction is organized into distinct channels, and the infrared behavior of the correction in the soft-photon limit is analyzed in detail. Preliminary numerical results and progress toward a full numerical evaluation will also be presented.