Seminar by Maria Olalla Olea Romacho (King’s College, London)

Title: ‘Traces from Primordial Magnetogenesis’

Speaker: Maria Olalla Olea Romacho (King’s College, London)

Venue&Time: Red Room / 15:00

Abstract: Magnetic fields permeate the Universe across a wide range of scales, from galaxies and clusters to the most underdense regions of the cosmic web. Gamma-ray observations of TeV blazars suggest the presence of magnetic fields in intergalactic voids, where no efficient late-time astrophysical sources exist, pointing toward a possible primordial origin and a direct link to early-Universe physics. Primordial magnetic fields arise naturally in scenarios such as inflation or cosmological phase transitions. In this seminar, I present a multi-messenger perspective on their observational signatures. On the particle physics side, I discuss collider-motivated models of electroweak phase transitions, highlighting connections to blazar observations and stochastic gravitational-wave backgrounds. On the astrophysical side, I show how primordial magnetic fields enhance small-scale structure formation, leading to dense dark matter minihalos that boost indirect detection signals, and how they impact high-redshift observables probed by the James Webb Space Telescope.