Search for Cosmological Magnetic Fields – COSMAG

Our project is aimed at the discovery and measurement of Primordial Magnetic Fields (PMFs) that are relics from the Big Bang. There exist several observational hints of the existence of such fields, such as evidence for non-zero magnetic fields in the voids of the Large Scale Structure in the present-day Universe or possible influence of magnetic field on the recombination process some 300 kyr after the Big Bang. We want to verify these hints with a new generation of observational tools that will become available over the next few years. We also want to combine complementary pieces of evidence to arrive at a self-consistent understanding of the PMF. The PMFs may have been produced in the Early Universe, during the first 10 microseconds after the Big Bang, at the moments of Inflation, Electroweak or quark confinement phase transitions. Following the moment of creation, the fields should have evolved during the expansion of the Universe. The PMF leaves observable imprints. At the moment of recombination, it influences the Cosmic Microwave Background Radiation (CMB). It survives as Intergalactic Magnetic FIeld (IGMF) till today and can be detected using the methods of gamma-ray astronomy. Our project will improve the gamma-ray and CMB probes of the PMF, using new gamma-ray telescopes (CTA, LHAASO) and CMB instruments (SPT-3G, SO, ACT, CMB-S4). We will work on data analysis and numerical / analytical modelling to support the data analysis and to build a self-consistent transfer function that relates the initial parameters of the PMF with its characteristics at the epoch of recombination and in the present-day Universe. Our project will leverage the discovery potential of a new generation of gamma-ray and microwave telescopes that will start taking data in the next few years. The project is also of potentially high impact. Confirmation of existence of the PMF will constitute a new cosmological probe, probing the Universe during the first millisecond of its existence.