Primordial Hypermagnetic Knots

TL;DR

This paper explores how hypermagnetic knots, topologically complex configurations of hypermagnetic flux, could influence baryon asymmetry and gravitational waves in the early universe, highlighting their formation, evolution, and potential observational signatures.

Contribution

It introduces the concept of hypermagnetic knots in the electroweak theory and analyzes their formation, decay, and implications for baryogenesis and gravitational radiation.

Findings

Hypermagnetic knots can seed the baryon asymmetry of the universe.

HK are washed out in the minimal standard model but may persist in extensions.

Hypermagnetic backgrounds can generate gravitational waves.

Abstract

Topologically non-trivial configurations of the hypermagnetic flux lines lead to the formation of hypermagnetic knots (HK) whose decay might seed the Baryon Asymmetry of the Universe (BAU).HK can be dynamically generated provided a topologically trivial (i.e. stochastic) distribution of flux lines is already present in the symmetric phase of the electroweak (EW) theory. In spite of the mechanism generating the HK, their typical size must exceed the diffusivity length scale. In the minimal standard model (MSM) (but not necessarily in its supersymmetric extension) HK are washed out. A classical hypermagnetic background in the symmetric phase of the EW theory can produce interesting amounts of gravitational radiation.