Cosmic Recombination with Primordial Magnetic Fields and the Hubble Tension.

Primordial Magnetic Fields (PMFs), long studied as potential relics of the early Universe, can accelerate recombination and have been proposed as a possible solution to the Hubble tension. In this seminar, I will present the latest observational evidence supporting this idea, based on comprehensive magnetohydrodynamic simulations of recombination in the presence of PMFs. Notably, the field strengths favoured by the data align with those required to explain galaxy cluster magnetic fields purely from primordial origins, eliminating the need for additional dynamo amplification or stellar contributions. High-resolution CMB temperature and polarization measurements will be crucial in confirming or further constraining the role of PMFs during recombination.