The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. However, usual galaxy surveys - even from the next-generation of telescopes and satellites - will not be able to probe the largest cosmic scales. In a recently published Physical Review Letters.

CENTRA's researchers Stefano Camera, Mário Santos and Luís Ferramacho have investigated a novel, cheap and feasible way to eventually access such ultralarge scale information. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z~1-5 are the best hope of accessing the ultralarge-scale information, directly related to the early Universe. A purpose-built HI intensity experiment may be used to detect the large scale effects of primordial non-Gaussianity, placing stringent bounds on different models of inflation. We argue that it may be possible to place tight constraints on the non-Gaussianity parameter f_NL, with an error close to ~1