Saved in:
Bibliographic Details
Main Authors: Hindmarsh, Mark, Lopez-Eiguren, Asier, Seppä, Riikka, Weir, David J.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.14204
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912716168364032
author Hindmarsh, Mark
Lopez-Eiguren, Asier
Seppä, Riikka
Weir, David J.
author_facet Hindmarsh, Mark
Lopez-Eiguren, Asier
Seppä, Riikka
Weir, David J.
contents Magnetic monopoles are an inevitable feature of post-inflation symmetry-breaking phase transitions in grand unified theories. Analytic estimates of their density indicate that they are compatible with standard cosmology only if their mass is less than $10^{11}$ GeV. We initiate a programme of numerical studies of monopole dynamics by simulating a gas of 't Hooft-Polyakov monopoles formed by the Kibble mechanism after a phase transition. In this paper we simulate monopoles in a radiation background, but without interactions with the radiation, in order to resolve differences between analytical models. We find that during the radiation era, the monopoles find each other and annihilate efficiently enough to keep their density fraction constant, which supports the modelling of Zel'dovich and Khlopov and Preskill in the epoch when plasma interactions can be neglected. In the matter era the density fraction decreases logarithmically. Further work is needed to quantify the effect of the thermal bath, which is expected to reduce the annihilation rate at later times.
format Preprint
id arxiv_https___arxiv_org_abs_2511_14204
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Numerical simulations of magnetic monopole evolution in an expanding universe
Hindmarsh, Mark
Lopez-Eiguren, Asier
Seppä, Riikka
Weir, David J.
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
Magnetic monopoles are an inevitable feature of post-inflation symmetry-breaking phase transitions in grand unified theories. Analytic estimates of their density indicate that they are compatible with standard cosmology only if their mass is less than $10^{11}$ GeV. We initiate a programme of numerical studies of monopole dynamics by simulating a gas of 't Hooft-Polyakov monopoles formed by the Kibble mechanism after a phase transition. In this paper we simulate monopoles in a radiation background, but without interactions with the radiation, in order to resolve differences between analytical models. We find that during the radiation era, the monopoles find each other and annihilate efficiently enough to keep their density fraction constant, which supports the modelling of Zel'dovich and Khlopov and Preskill in the epoch when plasma interactions can be neglected. In the matter era the density fraction decreases logarithmically. Further work is needed to quantify the effect of the thermal bath, which is expected to reduce the annihilation rate at later times.
title Numerical simulations of magnetic monopole evolution in an expanding universe
topic Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2511.14204