Scientists have made the most precise predictions yet of the elusive space-time disturbances caused when two black holes fly closely past each other. The new findings, published in the journal Nature, show that abstract mathematical concepts from theoretical physics have practical use in modeling space-time ripples. This paves the way for more accurate models to interpret observational data.
Gravitational waves are distortions in the fabric of space-time caused by the motion of massive objects like black holes or neutron stars. First predicted in Albert Einstein’s theory of general relativity in 1915, they were directly detected for the first time a century later, in 2015. Since then, these waves have become a powerful observational tool for astronomers probing some of the universe’s most violent and enigmatic events.
To make sense of the signals picked up by sensitive detectors like the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo, scientists need extremely precise models of what those waves are expected to look like. Until now, researchers have relied on powerful supercomputers to simulate black hole interactions, which require refining black hole trajectories step by step, a process that is effective but slow and computationally expensive. A team led by Mathias Driesse of Humboldt University in Berlin has taken a different approach.
Instead of studying mergers, the researchers focused on “scattering events” — instances in which two black holes swirl close to each other under their mutual gravitational pull and then continue on separate paths without merging.
Modeling black hole scattering events
These encounters generate strong gravitational wave signals as the black holes accelerate past one another.
To model these events precisely, the team turned to quantum field theory, a branch of physics typically used to describe interactions between elementary particles. Starting with simple approximations and systematically layering complexity, the researchers calculated key outcomes of black hole flybys: how much they are deflected, how much energy is radiated as gravitational waves, and how much the behemoths recoil after the interaction. Their work incorporated five levels of complexity, reaching what physicists call the fifth post-Minkowskian order — the highest level of precision ever achieved in modeling these interactions.
While calculating the energy radiated as gravitational waves, researchers found that intricate six-dimensional shapes known as Calabi–Yau manifolds appeared in the equations. These abstract geometrical structures have long been a staple of string theory, a framework attempting to unify quantum mechanics with general relativity. Until now, they were believed to be purely mathematical constructs, with no directly testable role tied to observable phenomena.
In the new study, however, these shapes appeared in calculations describing the energy radiated as gravitational waves when two black holes cruised past one another. This marks the first time they’ve appeared in a context that could, in principle, be tested through real-world experiments. These findings are expected to significantly enhance future theoretical models that aim to predict gravitational wave signatures.
Such improvements will be crucial as next-generation gravitational wave detectors — including the planned Laser Interferometer Space Antenna (LISA) and the Einstein Telescope in Europe — come online in the years ahead.
Kirstie a technology news reporter at DevX. She reports on emerging technologies and startups waiting to skyrocket.
