# Parker Bound and Monopole Pair Production from Primordial Magnetic Fields

**Authors:** Takeshi Kobayashi, Daniele Perri  
**arXiv:** [2207.08246](https://arxiv.org/abs/2207.08246)  
**Date:** 2022-07-17  
**Summary page:** https://www.summarizepaper.com/en/paper/2207.08246v2/

## Key points

- Authors Takeshi Kobayashi and Daniele Perri establish new constraints on the cosmic abundance of magnetic monopoles
- Bounds are based on survival of primordial magnetic fields during reheating and radiation-dominated epochs
- Refined bounds can be more stringent than traditional Parker bound and limits from direct searches for magnetic monopoles
- Analysis extends to monopoles generated by primordial magnetic fields via the Schwinger effect
- Applying refined bounds provides additional criteria for sustained existence of primordial magnetic fields
- Study enhances understanding of potential abundance of magnetic monopoles in cosmos and their interplay with fundamental particle physics processes during different epochs in early universe

## Summary

In their paper titled "Parker Bound and Monopole Pair Production from Primordial Magnetic Fields," authors Takeshi Kobayashi and Daniele Perri present new constraints on the cosmic abundance of magnetic monopoles. These bounds are established based on the survival of primordial magnetic fields during both the reheating and radiation-dominated epochs in the early universe. The study reveals that these refined bounds can be more stringent than the traditional Parker bound derived from observations of galactic magnetic fields, as well as limits obtained from direct searches for magnetic monopoles. Furthermore, the researchers extend their analysis to investigate monopoles generated by the primordial magnetic fields themselves through a phenomenon known as the Schwinger effect. By applying their refined bounds to this scenario, they are able to derive additional criteria for the sustained existence of these primordial magnetic fields. This comprehensive study not only enhances our understanding of the potential abundance of magnetic monopoles in the cosmos but also sheds light on the intricate interplay between primordial magnetic fields and fundamental particle physics processes during different epochs in the early universe. The findings presented in this research contribute valuable insights to ongoing investigations into cosmological magnetogenesis and high-energy physics phenomena.