We consider gravitational radiation and electromagnetic radiation from point mass binary with electric charges in a Keplerian orbit, and calculate the merger rate distribution of primordial black hole binaries with charges and a general mass function by taking into account gravitational torque and electromagnetic torque by the nearest primordial black hole. We apply the formalism to the extremal charged case and find that $\alpha=-(m_i+m_j)^2\partial^2 \ln { \cal R}(m_i,m_j)/\partial m_i \partial m_j=12/11$, which is independent of the mass function.
Categories: astro-ph.CO gr-qc hep-ph