Impact of Primordial Magnetic Fields on the First-Order Electroweak Phase Transition

TL;DR

This paper investigates how primordial magnetic fields influence the electroweak phase transition, revealing effects on transition dynamics, vortex formation, and baryon asymmetry generation in the early Universe.

Contribution

It provides a numerical analysis of magnetic field impacts on the electroweak phase transition, highlighting vortex structures and baryogenesis implications.

Findings

Magnetic fields slow down the phase transition process.

Vortex structures of Higgs condensation appear at certain magnetic field strengths.

Helical hypermagnetic fields significantly enhance sphaleron rates, aiding baryon asymmetry generation.

Abstract

We numerically study how the primordial magnetic field affects the first-order electroweak phase transition in the early Universe. We observe that: 1) the phase transition process would be slowed down by the magnetic field; 2) the phenomenon of vortex structure of the Higgs condensation appears when the homogenesis hypermagentic field $g'B_Y^{ex}/m_W^2\gtrsim3.63$; and, 3) the helical hypermagnetic field can dramatically enhance the sphaleron rate and validate the generation of the baryon asymmetry through the chiral anomaly.