Una técnica abandonada hace 20 años se revela ahora como precisa y barata para el estudio del Cosmos

The Asturias University Institute of Space Sciences and Technologies (ICTEA) of the University of Oviedo has led an advance that will contribute to bringing the scientific community a little closer to discovering the nature of dark matter and dark energy. The work proposes a solution to the problems observed in the main experiments on this matter, which offer incompatible results, thanks to a technique abandoned two decades ago in cosmology and which no offers the possibility of rigorous and more limited results. It is an additional, independent and competitive cosmological probe that can be applied perfectly to galaxy catalogues already available with no need for new and expensive observations (there are very few ways to measure these magnitudes and they usually depend on large machines and international collaborations).

In its day, with the number and type of known galaxies, this technique did not offer results as good as those achieved today, hence it was abandoned in favour of other methods with which it could now compete. It is based on the study of magnification bias (a weak gravitational lensing effect) that distant galaxies observed in the sub-millimetre spectrum are subject to.

This first work was only intended validate the probe's potential, although interesting results have already been obtained. In particular, it has enabled values below 0.24 to be excluded for the cosmological parameter of the density of matter and those greater than 1.0 for normalising the primordial power spectrum, which many of the main tools used up until now discarded. Now proven that it is a competitive method, researchers are already studying the different possibilities for improving the results. For example, they will go from analysing thousands of galaxies to millions, with the added difficulty that this entails.

The results of the research have come to light in the journal "Astronomy & Astrophysics" in an article by Laura Bonavera, Joaquín González-Nuevo, Marcos Muñiz Cueli, from the University of Oviedo ICTEA, with the participation of Cardiff University (United Kingdom), the International School for Advanced Studies in Trieste and the University of Tor Vergata in Rome (Italy). The study is endorsed by the University of Oviedo's Research Support and Promotion Programme (Aid for emerging research teams' projects, PAPI-19-EMERG-11), a State Programme project for generating Knowledge and Scientific and Technological Strengthening of the R&D+i System (PGC2018-101948-B-I00) and 200,000 calculation hours in the CINECA advanced computing centre (Italy).