Colloquium: Jennifer Schober (EPFL, Switzerland)

Cosmic magnetic fields: a new window to the early Universe

Magnetic fields are observed on virtually all length scales of the present-day Universe, from planets and stars to galaxies and galaxy clusters. Observations of blazars suggest that even the intergalactic medium is permeated by magnetic fields. Such large-scale fields were most likely generated very shortly after the Big Bang and therefore are a unique window into the physics of the very early Universe. In my talk, I will review theoretical models of magnetogenesis and confront these with observational constraints. I will address the possible origin of magnetic fields in the very early Universe, during inflation and the cosmological phase transitions, as well as their pre-recombination evolution in magnetohydrodynamical (MHD) turbulence. In particular, I will present results from high-resolution numerical simulations that show an efficient amplification of magnetic energy due to the so-called chiral anomaly, a standard model effect that necessarily leads to an extension of the MHD equations at high energies. 

• Date:
  March 31, 2022, 2:30 p.m. – 3:30 p.m.
  
  
• Location:

  Colloquium Zoom room

  
  
• Contact:
  Sydney Barnes