Evolution of inflation-generated magnetic field through phase transitions

TL;DR

This paper investigates how magnetic fields generated during inflation evolve through cosmological phase transitions, affecting their spectrum and inducing turbulence in the early universe.

Contribution

It provides new insights into the evolution of inflation-generated magnetic fields during phase transitions, including spectral modifications and turbulence generation.

Findings

Magnetic field spectrum remains nearly unchanged on large scales.

Small-scale power in the magnetic spectrum is suppressed after phase transitions.

Magnetic fields induce turbulence with a white noise kinetic energy spectrum.

Abstract

We study the evolution of an inflation-generated magnetic field, due to its coupling to fluid motions, during cosmological phase transitions. We find that the magnetic field stays almost unchanged on large scales, while on small scales the spectrum is modified in such a way that power at small scales becomes progressively suppressed. We also show that the magnetic field generates turbulent motions in the initially turbulence-free plasma. On large scales, the slope of the resulting kinetic energy spectrum is consistent with that of white noise.