UCL Department of Space and Climate Physics

Dr Ziri Younsi

Dr Ziri Younsi

UKRI Stephen Hawking Fellowship

Dept of Space & Climate Physics

Faculty of Maths & Physical Sciences

Joined UCL
1st May 2018



  • April 2021 - present  UKRI Stephen Hawking Fellow   [University College London]
  • May 2018 - March 2021  Leverhulme Trust Early Career Research Fellow   [University College London]
  • June 2017 - April 2018   Postdoctoral Fellow in Black Hole Camera project    [Goethe Universität Frankfurt, Germany]
  • June 2015 - May 2017   Alexander von Humboldt Fellow   [Goethe Universität Frankfurt, Germany]
  • October 2014 - May 2015   Postdoctoral Fellow in Black Hole Camera project   [Goethe Universität Frankfurt, Germany]

Academic Background

  • 2014   PhD Astrophysics   [MSSL, University College London]
  • 2008   MSc Physics   [University College London]
  • 2006   MA Mathematics   [University of Cambridge]

Research Summary

I work at the intersection between theory and observation. My research uses multi-wavelength polarised radiation transport to create physically accurate models of compact object environments, enabling scientific interpretation of observational data. This elucidates microphysical processes occurring therein, enabling constraints of key properties of black holes (BHs) like their mass, spin, and even the underlying spacetime geometry. I study covariant radiative transfer and magneto-hydrodynamical processes in BH systems, developing new formulations and numerical tools to accurately calculate the physical properties and behaviour of these systems, particularly on event horizon-scales.

I am an active member of the BlackHoleCam, Event Horizon Telescope (EHT), next-generation EHT (ngEHT: advanced successor to EHT), and Laser Interferometer Space Antenna (LISA: spaced-based gravitational wave detector) projects. I work on performing observational tests of strong-field gravity and alternative gravity theories using radiation and test particles (like pulsars). I also model and study observed flares, periodic outflows, and transient phenomena in compact object environments.

Within the EHT Collaboration (EHTC) I serve on the project's Science Council (2022+). I also co-lead the Gravitational Physics Working Group (WG) of the EHTC (2022+). Within the ngEHT I co-lead the Fundamental Physics WG (2021+).

Areas of Research

  • Black holes and compact object physics
  • Radiative transfer (photons and particles)
  • Tests of gravity
  • Accretion and magneto-hydrodynamical processes
  • Numerical and computational methods