August 11, 2025 — Waterloo, ON – A Perimeter Institute researcher is part of a collaboration named in a funding announcement made by the Simons Foundation today. The Simons Collaboration on Black Holes and Strong Gravity represents an $8 million investment in a network of multidisciplinary gravity and black hole experts at 12 institutions around the world. The network will develop a robust theoretical framework for deciphering the secrets encoded in gravitational wave (GW) data, including possible extensions to Einstein’s theory of general relativity.
Perimeter Faculty Member Luis Lehner, Carlo Fidani Rainer Weiss Chair in Theoretical Physics, is a specialist in general relativity who uses advanced mathematics and numerics to push the theory to its limits and hopefully find the cracks that lead to new physics. He is one of 12 principal investigators named in the funding announcement made by the Simons Foundation today, and the only Canadian representative.
Gravitational waves, as predicted by general relativity, are ripples in spacetime that propagate at the speed of light. They were first detected in 2015 by the Laser Interferometer Gravitational-Wave Observatory (LIGO), in Livingston, Louisiana, and Hanford, Washington. Today, GW science represents the best means to probe the physics of strong gravity.
Planned upgrades to the Advanced LIGO/Virgo/KAGRA gravitational wave detectors will double the sensitivity of these instruments in the coming years. Earth based detectors will also be joined by powerful new GW observatories in space, like ESA’s upcoming Laser Interferometer Space Antenna (LISA).
Nicolás Yunes, University of Illinois physics professor, will serve as the collaboration’s director for the full four-year term. “We’re moving toward the era of precision gravitational wave physics,” says Yunes. “This new era must be accompanied by a multidisciplinary effort to deepen our understanding of non-linear gravity. Otherwise, we will miss secrets encoded in the gravitational wave data, or worse, misinterpret our observations and be led in the wrong direction.”
Lehner joins physicists and mathematicians who specialize in strong gravity from theoretical, computational, and observational perspectives. Lehner says he is particularly inspired by fluid dynamics, a field that embraces non-linear approaches to problems.
“In physics, it’s common to begin with well-understood systems and then examine the departure from those systems when gently nudged,” he says. “I’m also interested in seeing what happens when we strongly kick it; we might encounter surprises.”
The $8 million grant will provide postdoctoral and graduate student support, fund travel between member institutions, and enable team meetings each year. The collaboration will enlist the expertise of associates – physicists, mathematicians, and data scientists – whose research programs are already immersed in these astrophysical mysteries. Researchers from this large, combined network will come together to tackle the deepest mysteries about our strong gravity universe.
“Gravitational waves enable the strongest stress test we can use on the theory of general relativity,” says Lehner. “The theory may fail, and if it does, that would be wonderful, because it will point us in new directions and spark novel ideas. It’s all about trying to understand gravity from all angles.”