On ab initio closed-form expressions for gravitational waves.

We introduce an approach for finding ab initio, high accuracy, closed-form expressions for the gravitational waves emitted by binary systems. Our expressions are built from numerical surrogate models based on numerical relativity simulations, which have been shown to be essentially indistinguishable from each other, with the advantage that our expressions can be written explicitly in a few lines. The key new ingredient in this approach is symbolic regression through genetic programming. The minimum overlap obtained in the proof of concept here presented, compared to ground truth solutions, is 99%.