Marios Christodoulou and Lin-Qing Chen
April 2025
Quantum Information Structure of Spacetime (QISS) II Conference in Vienna
The Quantum Information Structure of Spacetime (QISS) II Conference took place from 14–17 April 2025 at the University of Vienna’s Faculty of Physics. As the summary conference of the QISS II consortium, the event brought together over 150 researchers from around the world to discuss new developments and insights at the intersection of quantum gravity and quantum information.
Organized by a team of researchers from IQOQI-Vienna, the conference adopted a highly interactive, discussion-focused format. Rather than a long sequence of seminars, the program featured concise presentations by young researchers—followed by ample time for questions, dialogue, and collaboration. The discussion sessions were described by many attendees as very inspiring, lively, and intellectually fruitful, fostering new ideas and potential collaborations.
The conference was structured around six sessions, each highlighting a key research area within the QISS initiative. Each session was chaired by a leading expert in the field and featured presentations from emerging researchers:
Entanglement in Spacetime Chair: Eugenio Bianchi | Speakers: Pietro Dona, Lucas Hackl
Quantum Gravity Phenomenology Chair: Francesca Vidotto | Speakers: Wolfgang Wieland, Marios Christodoulou
Philosophical Insights into Quantum Gravity Chair: Jeremy Butterfield | Speakers: Henrique Gomes, Aristotelis Panagiotopoulos
Quantum Reference Frames for Quantum Spacetimes Chair: Renato Renner | Speakers: Viktoria Kabel, Joshua Kirklin
Quantum Causal Structure in Quantum Spacetimes Chair: Bob Coecke | Speakers: Augustin Vanrietvelde, V. Vilasini
Table-top Quantum Experiments for Gravity Chair: Sougato Bose | Speakers: Flaminia Giacomini, Richard Howl
In addition to these sessions, a special talk on the history of quantum gravity was delivered by Bernadette Lessel, offering valuable context and reflection on the field's development.
In celebration of World Quantum Day on 14 April, the organizers hosted a special welcome event featuring a unique quantum music performance by Bob Coecke, joined by Kazakh composer and pianist Rakhat-Bi Abdyssagin. In a creative fusion of science and art, Bob demonstrated “what a qubit sounds like” to the audiences. The evening culminated in a lively and spontaneous jam session by the conference participants.
The QISS II Vienna Conference was appreciated by the participants for its dynamic format, collaborative spirit, discussion focus and the depth of scientific exchange it fostered. The event concluded with a warm expression of appreciation, as the community came together to acknowledge consortium leader Carlo Rovelli, co-leader Marios Christodoulou for their visionary leadership, and the organizing committee for their dedication over six remarkable years of the consortium.