Primordial Magnetic Fields May Solve One of Cosmology’s Biggest Mysteries

Scientists propose that extremely faint primordial magnetic fields could change recombination and alter CMB patterns used to infer the Hubble constant.

Planck CMB analyses give about 67 km/s/Mpc while local distance measurements using Type Ia supernovae give about 73 km/s/Mpc, a difference called the Hubble tension.

The new study ran full 3D simulations of primordial plasma with magnetic fields, computed resulting CMB predictions, and tested them against observations.