I am Ziri Younsi, a UKRI Stephen Hawking Fellow at University College London. I work primarily on radiation transport in strong gravity, and my research is concerned with trying to understand the nature and physical properties of black holes and other compact objects.

I am interested in how the intense gravitational fields of black holes, coupled with the microphysical properties and dynamics of their surrounding accretion discs and relativistic jets, serve to mediate radiation production in the vicinity of the event horizon. My research is focussed on calculating physically-accurate models of this radiation, using a combination of theory, computational astrophysics, and observational data to construct synthetic images, spectra, and light-curves.

For these purposes I authored and maintain the general-relativistic radiation transport (GRRT) code, “BHOSS”, which solves the equations of covariant polarised radiative transport, fully incorporating the effects of both special relativity and general relativity. By interfacing BHOSS with general-relativistic magnetohydrodynamics (GRMHD) simulations, I calculate the multi-frequency polarised emissions from turbulent plasmas surrounding black holes, enabling constraints on black-hole mass and spin, accretion physics, and even perform strong-field tests of gravity.