Black hole simulations in massive dynamical Chern-Simons gravity*

Astrophysical black holes (BHs) provide a laboratory to test deviations from Einstein’s General Relativity (GR); for instance, no-hair theorems state that BHs in GR are parameterized by only three conserved quantities: mass, angular momentum, and electromagnetic charge. As an example, previous authors have considered massive scalar fields evolving in GR around a BH to investigate the violation of no-hair theorems via the formation of scalar clouds. Similarly, rotating BHs in modified theories of gravity, such as dynamical Chern-Simons (dCS) gravity, have been considered to investigate the formation of scalar “hair”. In this talk, I will combine the two efforts and present numerical simulations of a massive scalar field in dCS gravity evolving in the background of a Kerr BH. From these simulations, I will explore the effect of non-minimal coupling to curvature via the Pontryagin density on the massive scalar field as well as the effect of the massive scalar field on the evolution of dCS hair. Finally, I will investigate the spectrum of characteristic frequencies in massive dCS gravity from our numerical simulations and compare it with the spectrum of characteristic frequencies in GR.