Role of Charged Gauge Fields in Generating Magnetic Seed Fields in Bubble Collisions during the Cosmological Electroweak Phase Transition

TL;DR

This paper calculates magnetic seed fields generated during bubble collisions in a first-order electroweak phase transition, showing that charged W fields can produce fields comparable to previous estimates, potentially seeding cosmic magnetic fields.

Contribution

It provides a linearized analytical model for magnetic field generation from charged gauge fields during bubble collisions in the electroweak phase transition.

Findings

Magnetic fields generated are comparable to previous estimates.

Solutions are expressed in closed form using boundary conditions.

Generated magnetic fields could seed present-day cosmic magnetic fields.

Abstract

We calculate the magnetic field generated during bubble collisions in a first-order electroweak phase transition that may occur for some choices of parameters in the minimal supersymmetric Standard Model. We show that for sufficiently gentle collisions, where the Higgs field is relatively unperturbed in the bubble overlap region, the equations of motion can be linearized so that in the absence of fermions the charged W fields are the source of the electromagnetic current for generating the seed fields. Solutions of the equations of motion for the charged gauge fields and Maxwell's equations for the magnetic field in O(1,2) space-time symmetry are expressed in closed form by applying boundary conditions at the time of collision. Our results indicate that the magnetic fields generated by charged $W^{\pm}$ fields in the collision are comparable to those found in previous work. The magnetic fields so produced could seed galactic and extra-galactic magnetic fields observed today.