Anisotropic Neutrino Emission from Spinning, Moving, and Charged Primordial Black Holes

Abstract

The angular and spectral features of neutrinos emitted from primordial black holes (PBHs) carry key imprints of the black hole's fundamental properties. This work investigates the directional emission of neutrinos from Kerr-Newman PBHs undergoing Hawking evaporation, accounting for the combined effects of spin, motion, and electric charge. Rotation induces anisotropic fluxes through axisymmetric geometry and spin-dependent greybody factors, while relativistic motion leads to pronounced Doppler beaming along the direction of travel. Electric charge modifies the thermodynamic evolution and suppresses the emission of like-charged particles, altering the overall spectrum and burst duration. The resulting neutrino flux exhibits rich angular structure, energy dependence, and time profiles that vary with PBH parameters. These directional signatures enhance the prospects for detection at current and future neutrino observatories, and offer new multi-messenger probes of PBH populations in the early universe.