Thomas Spieksma successfully defended his thesis on Thursday, 4 September, in the historic Auditorium A at the Niels Bohr Institute. His dissertation, Exploring Black Hole Environments, presented new results on the impact of astrophysical environments on black holes, both in isolation and within binary systems. He advanced the modelling of various environments, including clouds of ultralight bosonic particles and plasmas around black holes, while placing strong emphasis on detectability prospects: given these environments, could they be observed with next-generation detectors?

After a 45-min presentation, the committee consisting of Prof. Paolo Pani (Sapienza University of Rome), Dr. Katy Clough (QMUL, London), and Prof. Troels Harmark (NBI) posed a series of questions, which he answered with success. The defence concluded in a festive spirit, with champagne opened outside the building on a graciously sunny day in Copenhagen. The photos capture some moments from the event.

Thomas will continue his academic career at the University of Oxford with Dr. Samuel Witte, focusing on the role of ultralight bosonic fields in binary black hole systems. With luck, he will have many opportunities to return to the Center of Gravity.