Bridging High and Low Energies in Search of Quantum Gravity 2025
Bridging High and Low Energies in Search of Quantum Gravity 2025
August 13, 2025
The COST Action BridgeQG First Annual Conference, titled “Bridging High and Low Energies in Search of Quantum Gravity 2025“, was held from June 7–10, 2025, at the Laboratoire de Physique Nucléaire et des Hautes Énergies in Paris. The event brought together over 100 participants in person and more online, representing a broad spectrum of physicists working on the theoretical, phenomenological, and experimental aspects of quantum gravity.
In the spirit of the COST Action, which aims to bring together scientists with a variety of complementary expertise, the conference fostered interdisciplinary exchange collaboration. By developing a common language and focusing on shared objectives, the initiative seeks to accelerate progress at the interface between high-energy quantum gravity and quantum aspects of gravity in the weak-field regime, helping to bridge the gap between fundamental theory and phenomenological applications. The phenomenology of quantum gravity has flourished over the past two decades, while efforts on the side of fundamental theory have increasingly focused on making contact with observations. Several approaches have now reached a level of maturity sufficient to yield concrete predictions. From particle and astroparticle physics to cosmology, and even to tabletop experiments, a wide range of physical arenas is now being explored in the search for signatures of quantum gravity.
This conference was the first meeting of the COST Action, offering collaborators from the five working groups an opportunity to present their ongoing research. The working groups are: High-energy quantum gravity theory, High-energy quantum gravity experiment, Low-energy gravitational effects in quantum systems, Low-energy high-precision experiment, Connection between low-energy and high-energy quantum gravity, Dissemination and Diversity. Each group had an introductory session and a dedicated series of contributed talks, highlighting the progress made within their respective areas of focus.
Among the many contributions, Roukaya Dekhil, Renata Ferrero, Roman Kemper, Yongge Ma, Lisa Mickel, and Wolfgang Wieland presented talks on recent developments in cosmological models in GFT, theoretical aspects of gravitationally induced neutrino decoherence, effective models for black holes in LQG, quantum cosmology, and light-cone quantization and luminosity bounds
Alongside the scientific program, the conference featured an outreach talk and a physics seminar, embedding the event within the vibrant physics life of Paris and fostering engagement with both the broader scientific community and the public.
