On Thursday 21 April, in a special issue of the journal "Journal of Cosmology and Astroparticle Physics", eight articles signed by the international collaboration QUBIC (Q&U Bolometric Interferometer for Cosmology), which is making a telescope in Argentina for the study of the early universe that will make use of an innovative technique. QUBIC, in fact, will observe and map the properties of the cosmic microwave background, the residual echo of the Big Bang, focusing on the measurement of particular components of the orientation of the oscillation of the microwaves of the cosmic microwave background radiation on the plane of the sky (polarization), called B-modes, indicative of the possible perturbations induced by the gravitational waves generated in the first moments of life of the universe. The project sees Italy as a protagonist thanks to the scientific and technological contributions provided by the INFN (National Institute of Nuclear Physics) and the Universities of Milano Statale, Milano-Bicocca, University of Rome "Tor Vergata" and Sapienza University of Rome. QUBIC will observe the sky from the end of 2022, from a high-altitude desert site (5000 m) in Argentina, near San Antonio de Los Cobres.
After its development and integration in the European laboratories of the universities and research institutions involved in the collaboration, QUBIC arrived in Argentina, in the city of Salta, in July 2021, where the final stages of calibration and laboratory testing are proceeding. The results of these activities, presented in the eight articles published in the 'Journal of Cosmology and Astroparticle Physics', have confirmed the correct functioning of the instrument and of the 'bolometric interferometry', that is the newly developed technique on which QUBIC's observations will be based, which combines the very high sensitivity of detectors cooled to almost absolute zero (-273 °C) and capable of measuring the energy of the radiation of the cosmic background transforming it into heat (bolometers), with the precision of interferometric instruments.