“…In the long-term, it may be possible to obtain even better estimates from observations, perhaps based on maps of the 21-cm emission of neutral hydrogen [19,20]. On the theoretical side, predictions for the non-gaussianity generated in a large collection of relevant models have become available over the last several years [21,22,10,23,24,25,26,27,28,29,30,8,31,32,33], following Maldacena's successful calculation of the bispectrum produced in single-field, slow-roll inflation [34].…”