LSU Postdoctoral Researcher Beatriz Elizaga Navascués Wins Bronstein Prize in Loop Quantum Gravity

The Bronstein Prize is awarded every two years to a leading postdoctoral scholar in loop quantum gravity, an area in theoretical physics that helps bridge general relativity with quantum mechanics to provide a deeper understanding of our universe and everything in it. LSU is one of the top three universities for loop quantum gravity research in the United States.

Beatriz Elizaga Navascués, originally from Madrid, Spain, joined LSU’s Hearne Institute of Theoretical Physics last year to work with professors Jorge Pullin and Ivan Agullo and continue a promising line of research—using observations of extreme and enormous phenomena, such as the beginning of the universe and black holes, to improve our understanding of physical forces and matter on an atomic level.

“Studying quantum gravity can be very theoretical, very mathematical and very dry,” Elizaga Navascués said. “But my whole research career has been to try to bridge between that and realistic systems in our universe we can actually see.”

Part of her choice to come to LSU was to be able to learn from LSU, Caltech and MIT researchers at the Laser Interferometer Gravitational-Wave Observatory, or LIGO, in Livingston, Louisiana, where gravitational waves were first detected in 2015.

“The idea that we may be able to grasp glimpses of how gravity behaves at the quantum level on a microscopic scale from astronomical observations at a macroscopic scale is mind-blowing to me,” Elizaga Navascués said. “Black holes and light coming to us from across the universe, from a distant past, could be a source for us to learn about fundamental aspects of physics that we may not be able to observe any other way." 

Loop quantum gravity is one of two leading frameworks that attempt to make Albert Einstein’s general theory of relativity—our best theory of how things work at galactic and intergalactic scales—and quantum mechanics—our best theory of how things work at microscopic scales—agree with each other. It may be hard to understand why this would matter, but a longstanding Holy Grail of science is finding a theory that unifies our understanding of all fundamental forces (gravity, electromagnetism and the weak and strong nuclear forces) that explains reality at every scale. Even Einstein could not do it. And there are at least two places where bridging subatomic and intergalactic scales is vital: Black holes are the largest gravitational sources in the universe and yet their formation ends up concentrating enormous masses in very small places, and so, both theories come into play. Similarly, at the Big Bang, all matter and energy in the universe occupied a tiny volume. In both cases, we need a theory of quantum gravity to describe what happened. Loop quantum gravity researchers do this by leaning into the math and looking at the universe atomically, as a large whole made up of smallest parts where the relationships between the parts, not just the parts themselves, change as objects move, no matter how large or small, slow or fast. One of the biggest challenges in theoretical physics today is explaining observed phenomena that current models fail to explain by coming up with new math that is so complex, it’s difficult to visualize. We know the math is correct when it’s able to predict observable results from physical experiments, but we currently have no model we can use to measure all reality where the math really makes sense.

Last week, Elizaga Navascués was awarded the Bronstein Prize at the biannual Loops’24 conference at Florida Atlantic University in Fort Lauderdale, Florida, which, together with LSU and Penn State, is home to a cluster of internationally prominent loop quantum gravity researchers. The Bronstein Prize is named after the first researcher to emphasize that quantum gravity requires a deep revision of classical space-time concepts as explained by Einstein.

“Our area is so specialized, you need to work in it to be able to understand the ultimate consequences of each other’s work,” Elizaga Navascués said. “So, it’s very satisfying to be recognized by the people in my research community who understand my work at the deepest levels.”

Elizaga Navascués received her Ph.D. in Physics from Complutense University of Madrid in 2017 and then spent three years at the Friedrich-Alexander University in Erlangen-Nurnberg, Germany, and two years at Waseda University in Japan. In Japan, she got a traditional tattoo of a colorful koi fish on her left forearm. It swims in loops around her as she walks in loops around the LSU Lakes, pondering the elasticity and geometry of spacetime. 

“I love walking; I go to the levee and around the lakes,” Elizaga Navascués said. “Looking around, I enjoy observing things around me. The scenery is changing continuously, but slowly enough that I can take in a lot of information from what I’m seeing. It’s just beautiful to observe and try to really see what I’m looking at.”