Living on the Edge: Black Holes as Lampposts for Quantum Gravity

We live in an era marked by LIGO’s discovery of gravitational waves from coalescing black holes and by the Event Horizon Telescope’s imaging of horizon-scale black-hole structure. These remarkable achievements confirm Einstein’s general relativity, while sharpening a central puzzle of fundamental physics: how gravity interfaces with quantum field theory. After a brief review of the essential physics of black holes, I will motivate a route to quantum-gravity effects that does not rely on committing to a specific ultraviolet completion. The strategy is model independent and is formulated in terms of effective metric descriptions of quantum black holes, constrained by near-horizon regularity and by the finiteness of physical observables. I will show how these requirements strongly restrict admissible metric deformations and lead to concrete consequences for thermodynamic and observational properties. The broader message is that black holes can serve as controlled lampposts for isolating corrections to spacetime dynamics and, ultimately, for connecting quantum gravity to data.

Speaker biography

Francesco Sannino is Director of the Quantum Field Theory Center (QTC) at the University of Southern Denmark and Professor of Theoretical Physics at the University of Naples Federico II. He is founder of the Centre for Cosmology and Particle Physics Phenomenology (CP3-Origins), and the founder of the Danish Institute for Advanced Study (DIAS). He is Editor-in-Chief of Annals of Physics. Elected member of the Danish Royal Academy of Science and Letters and the Finnish Academy of Science and Letters. His research spans quantum field theory, particle physics, cosmology, and quantum gravity. He has made foundational contributions to the conformal dynamics of gauge theories and to minimal composite extensions of the Standard Model, and he discovered the first controlled four-dimensional asymptotically safe gauge–Yukawa theories beyond asymptotic freedom.He has held positions and long-term visits at leading institutions including Yale University, CERN, MIT, Nordita, Harvard, SLAC at Stanford, and the Niels Bohr Institute.