Ronald Rodgers, researcher at Nordita, studies quantum gravity using celestial holography. Illustration by Alessia Ferraro.
How do you make sense of gravity at the tiniest possible scales, around black holes or moments after the Big Bang? Modern physics relies on two powerful theories: quantum field theory, which describes particles, and general relativity, which describes gravity. But these theories don’t fit together, and finding a way to merge them into a single framework—quantum gravity—is one of the biggest open questions in theoretical physics. At Nordita, researcher Ronald Rodgers is taking on this challenge with support from a recently awarded grant from the Olle Engkvist foundation.
“The grant gives me a great opportunity to establish myself as an independent researcher, and I’m very happy that receiving it means I can stay part of the exciting and stimulating research environment at Nordita,” Ronald says. “I’m looking forward to connecting different areas of theoretical physics and to work on topics that are new to me, such as scattering amplitudes.”
One of the most promising paths toward quantum gravity is holography—the idea that a gravitational theory can be understood by studying a completely different, dual theory. Ronald’s project focuses on a new and rapidly developing version of this idea: celestial holography, where quantum gravity is linked to a special kind of quantum field theory known as a celestial field theory. To make progress, researchers need to understand these celestial theories in far more depth than today’s tools allow.
Ronald’s work brings two powerful concepts into the celestial holography toolkit: defects, which are locations where the physics changes from its surroundings, and quantum entanglement, measured through entanglement entropy. By determining which defects and boundaries are possible in celestial field theories, and by using entanglement to reveal new constraints and relationships, the project aims to uncover previously inaccessible information about the dynamics of quantum gravity. This includes new ways of studying black holes through their celestial duals.
The work is pioneering: both the study of defects in celestial holography and the calculation of entanglement entropy in this setting are new directions, and Ronald will apply methods he recently developed to push the field forward. The results will lay the groundwork for future models, provide new computational tools, and open a path to understanding quantum gravity in a way that connects directly to the physics of our universe.
Learn more about Ronald Rodgers’ research on his website.
