Computing gravitational waves from the early universe in seconds?

Gravitational waves from the early universe carry fingerprints of exotic inflationary physics, but computing their spectra with non-Gaussian statistics has been prohibitively slow. By decomposing the key integrals into about 50 convolutions solvable via fast Fourier transforms, the new public code FLAN-SIGW runs on a consumer GPU and delivers results within 10% accuracy in seconds. This could make it practical to scan large swaths of inflationary model space against data from detectors like LISA or pulsar timing arrays.