Research Seminars @ Illinois

Astrophysical black holes are not isolated vacuum objects. They are embedded in surrounding matter and fields. The increasing precision of observations makes it essential to quantify how such environments influence gravitational and electromagnetic observables. In this talk, I will discuss exact solutions for static, spherically symmetric black holes surrounded by anisotropic matter, with emphasis on Kiselev-type geometries as a simple, interpretable framework for studying environmental effects. I will describe how the surrounding medium modifies horizon structure and effective potentials for test fields, including recent results for charged massless scalar perturbations. I will also outline how these solutions can be implemented in numerical relativity codes such as the Einstein Toolkit, providing a modular, analytically controlled testbed for probing environmental effects in the time domain.