Modeling Charge in Black Hole Binary Mergers Using the Backwards One Body Model

Electric charge is generally neglected when considering astrophysical black holes (BHs), although it is permitted by the no hair theorem, with charged and spinning black holes being described by the Kerr-Newman solution. Einstein-Maxwell theory, the simplest and most widely used model for combining gravity with electromagnetism, works simply by inserting the electromagnetic stress-energy tensor into Einstein's equations. The Backwards-One-Body (BOB) model has been shown to precisely model the strain for the late inspiral, merger, and ringdown for BH mergers forming Kerr BHs. We will present the application of BOB model to Kerr-Newman BH merger remnants. In order to demonstrate the validity of BOB within the Kerr-Newman regime, numerical relativity simulations of merging charged black holes were performed with a modified version of the Einstein Toolkit [Bozzola (2021)]. This work can be generalized to magnetic charges, dark-sector charges, gravitational charges, and other tests of fundamental physics.