Prior research on black hole collisions analyzed gravitational wave behavior using linear math, implying that the gravitational waves that rippled outward were independent. Now, new research has more precisely modeled the same collisions and exposed so-called nonlinear effects.

When waves on the beach crest and crash, nonlinear effects occur. Instead of traveling in isolation, the waves interact and impact one another.

Keefe Mitman, a Caltech graduate student who works with Saul Teukolsky (Ph.D. ’74), said, “We anticipated these effects with something as violent as a black hole merger, but we had not yet observed them in our simulations. The waveforms from our simulations may now be extracted using new techniques, making it possible to observe the nonlinearities.”