Modeling Electromagnetic Radiation from Gravitational Wave Sources at Different Scales

In 2017, the first detection of gravitational waves (GW) from a binary neutron star merger by the LIGO/VIRGO collaboration was followed by electromagnetic (EM) observations spanning the whole spectrum, from gamma rays to radio. This event, dubbed GW170817, has shown multi-messenger astrophysics' vast potential to understand matter under extreme conditions. In the next decade, new EM facilities such as the Vera Rubin Observatory and Roman space telescope, along with next-generation GW detectors such as the space-borne LISA, will bring new data to understand the evolution of compact objects at different scales, from stellar mass objects to supermassive black holes.

Theoretical models of multimessenger GW sources have also greatly improved in recent years due to advances in our computational capabilities. Multi-physics simulations are essential to obtain reliable predictions from these systems and must include General Relativity, nuclear physics, magnetohydrodynamics, and radiation transport.

In this talk, I will give an overview of recent efforts to simulate multi-messenger gravitational wave sources at different scales. In particular, I will show how accretion processes mediate many of the observational features in these systems and how similar techniques can be applied to study a variety of compact objects and their interaction. I will finish by presenting the current and future challenges of theory in this new era of multimessenger astrophysics.