From 7–10 July 2025, the BridgeQG 2025 conference gathered an international community at LPNHE in Paris, bringing together theorists and experimentalists working at the frontiers of quantum gravity phenomenology. Funded by the COST Association under Action CA23130, the event featured four days of intense and inspiring exchange between high‑energy and low‑energy quantum gravity researchers.
Monday July 7: The conference opened with introductory sessions by the leaders of WG1, WG2, WG3, WG5 and WG6, covering theoretical high-energy quantum gravity perspectives, experimental approaches, low-energy gravitational effects in quantum systems, precision experiments, bridging opportunities between energy scales, and dissemination plans. The opening concluded with a welcome cocktail.
Tuesday July 8: The day focused heavily on high-energy quantum gravity theory talks on probing quantum gravity at all scales, Lorentz symmetry violations, gravitational wave bounds, and black hole quantum foundations. Experimental sessions covered astroparticle investigations of Lorentz invariance violations (LIV) using gamma-ray observations and neutrino studies. Low-energy quantum-gravitational effects sessions explored the quantum Einstein equivalence principle and novel diffusion-based tests. The day was concluded with a public outreach event on gravitation by Philippe Jetzer.
Wednesday July 9: The program balanced low-energy quantum systems research (quantum-classical theories, reference frame transformations, angular momentum entanglement) with continued high-energy theory covering spacetime regularization, noncommutative spacetimes, Planck-scale deformations and cosmological effects on LIV searches. Precision experiment sessions showcased micro-mechanical oscillators for gravity exploration and underground quantum mechanics tests. The day was concluded with a seminar by Physics department seminar by the COST Action chair Giulia Gubitosi.
Thursday July 10: The final day emphasized connections between low and high-energy quantum gravity through talks on modified dispersion relations, generalized uncertainty principles, and quantum black hole phenomenology. High-energy theory sessions concluded with discussions of κ-Minkowski symmetries, QED, and superimposed quantum universes. The conference wrapped up with general discussions and a management committee meeting to plan future activities.
For the full schedule and the slides of the talks, please visit: https://indico.in2p3.fr/event/34939/timetable/