First Order QED Corrections to Hawking Radiation from Asteroid Mass Primoridal Black Holes

Asteroid mass primordial black holes (mass 10¹⁶ - 10²¹ grams) are viable candidates to describe the total dark matter content of the universe. Becase primordial black holes (PBHs) in this mass range have a Hawking temperature is greater than 100 keV, charged particle pairs can easily be created for nontrivial hawking radiation signatures as a dark matter signature. Since these processes are on the Quantum Electrodymanic (QED) energy scales, it is necessary to rigorously investigate the Hawking radiation spectra not just at zeroth order, but also at first order where electrons and positrons could also interact with emitted photons. Previously, our group has created an analytic expression for the first order Hawking radiation spectra from dissipative effects for a Schwarzschild PBH. This talk will discuss the numerical implementation of that result for a range of PBH masses. Our calculation confirms the expectation that at low energies, the inner bremsstrahlung radiation is the dominant contribution to the Hawking radiation spectrum. We compare the low-energy tail in our curved spacetime QED calculation to several approximation schemes in the literature, and find deviations that could have important implications for constraints from Hawking radiation on primordial black holes as dark matter. This work is critical in understanding upcoming keV-MeV surveys that will be able to directly search for asteroid mass PBHs, and is part of the first steps towards a complete treatment of QED interactions on black hole spacetimes.