Using numerical simulations to probe fundamental physics in strong gravity regimes

Numerical relativity simulations have allowed us to isolate and characterise the gravitational wave signals from merging black holes and neutron stars, giving us information about their parameters and astrophysical origins. The same simulations provide an opportunity to probe new effects beyond the standard model + GR paradigm, including new particles and fields, modifications to gravity, and strong gravity effects in the early universe. I will give an overview of the state of the art in such simulations, discuss their main challenges and highlight their potential to shed light on fundamental questions.