Primordial magnetic fields may explain the Hubble tension

Scientists ran the first full 3D simulations of primordial plasma with embedded magnetic fields and tested their effect on recombination. Data show a mild preference for fields of about 5–10 pico-Gauss, which could help reconcile the 67 vs 73 km/s/Mpc discrepancy in the Hubble constant.

• Hubble constant discrepancy: 67 vs 73 km/s/Mpc
• Primordial fields speed up recombination and shift CMB patterns
• Data show a 1.5–3 sigma preference for such fields
• Field strengths of 5–10 pico-Gauss match galactic seed fields