Theoretical physicists studying self-dual gravity and self-dual Yang-Mills theory found a way to combine an infinite tower of hidden symmetries into a single resummed form. They also wrote an explicit formula for n-particle quantum amplitudes as one determinant.
Quantum field theory calculations often grow explosively as more particles interact, making them slow or impossible. Showing that one symmetry structure fixes the whole wavefunction — and compresses it into a single determinant — gives physicists a far more efficient tool for computing the fundamental interactions that models of matter and spacetime rest on.
✦ Sometimes infinite complexity hides a single elegant rule.