Before revision:  These surrogates have the salient feature of being essentially indistinguishable from or very close to supercomputer simulations of the Einstein equations  but can be evaluated in less than a second on a laptop.
After revision:  These surrogates have the salient feature of being essentially indistinguishable from or very close to supercomputer simulations of the Einstein equations , but can be evaluated in less than a second on a laptop.