A Major Quantum Event in Bratislava

_ 27/04/2026_ Diana Cencer Garafová

Bratislava, April 21. – 24. 2026 — Gravity is the faintest of nature’s forces – and yet it shapes the universe. Last week, scientists gathered in Bratislava to ask a bold question: what happens when gravity meets the quantum world?

Bratislava hosted global experts on quantum information and gravity at the international conference Observers and Causality in Quantum Gravity (OCQG 2026).

The event brought together researchers working at the edge of two of the most profound areas of modern science: quantum theory – the physics of the very small – and gravity – the force governing the cosmos at the largest scales. While these domains have traditionally been studied separately, recent advances are beginning to reveal surprising and deep connections between them. This conference aimed to create a rare platform for dialogue between communities that do not often overlap: experts in quantum gravity and quantum information, and to clarify key ideas and spark new interdisciplinary approaches to some of physics’ deepest questions.

“After many years of research on causality in quantum information and gravity, I was delighted to bring such a diverse and distinguished group of researchers to Bratislava. It was truly rewarding to see participants actively engaged in high-level discussions on fundamental physics that the conference fostered.”
Natália S. Móller, Institute of Physics of the Slovak Academy of Sciences, the main organizer of the event

The conference gathered 165 participants from across the globe, including several prominent figures shaping the field. The opening lecture was delivered by Professor Fay Dowker (Imperial College London), a former student of Stephen Hawking and a leading expert on causality in quantum gravity. Other keynote speakers included Professor Renato Renner (ETH Zurich), known for his pioneering work in quantum information and security, who will present new insights into the so-called “third particle paradox,” Professor Časlav Brukner (University of Vienna), who discussed fundamental limits of quantum measurements and their implications for our understanding of reality, and Dr. V. Vilasini (Inria, Université Grenoble Alpes), who contributed fresh perspectives through her work about causality in quantum theory and Wigner’s friend paradox.

„This meeting reflected the growing recognition that gravity and quantum information are fundamentally interconnected, and highlighted the importance of sustained dialogue between these communities.“
Martin Krššák, Comenius University in Bratislava, a co-organizer of the event.

As the scientific community continues its search for a unified description of nature, OCQG 2026 marked an important moment: a growing recognition that gravity and quantum information are not separate stories, but parts of a deeper, unified narrative still waiting to be understood.

About the organisation:

The conference was organized by the Institute of Physics of the Slovak Academy of Sciences (IP SAS), Comenius University (CU), and the Slovak National Center for Quantum Technologies (QUTE.sk) under the umbrella of two European COST Actions focused on bridging quantum physics and gravity: Relativistic Quantum Information (RQI) and Bridging High and Low Energies in Search of Quantum Gravity (BridgeQG). The RQI action brings together more than 500 researchers worldwide and examines how new quantum technologies impact fundamental physics, especially theories based on Einstein’s relativity, while also exploring how fundamental physics can influence areas such as quantum computing and quantum cyber-security. BridgeQG focuses on connecting approaches across different energy scales in the search for a consistent theory of quantum gravity.