Search for primordial gravitational waves moves forward

Nature : Last week it was confirmed that the apparent ripples in the cosmic microwave background (CMB) radiation detected by BICEP2 were almost entirely due to intergalactic dust. Nevertheless, researchers have been continuing to develop more sensitive experiments to look even more closely at the CMB. A set of five telescopes, each individually as sensitive as BICEP2, called the Keck Array, is undergoing upgrades that will allow it to measure both the dust and the CMB in the same patch of sky. BICEP3, the successor to BICEP2, will match the Keck Array’s sensitivity in a single telescope. The biggest difference from its predecessor is that BICEP3 will be examining the sky at the lower 95 GHz frequency, where it is believed dust will cause less interference on potential signals. Both BICEP3 and the Keck Array will be looking at the same area of sky as BICEP2 did, but two other projects are already looking at wider areas of the sky and could potentially find a signal before either BICEP3 or the Keck Array is operational.