Non-standard cosmic strings with amazing profiles
Abstract
It is an unnatural feature of the Standard Model that the difference between the baryon number B and the lepton number L is conserved, which implies an exact, global symmetry. We promote it to a naturally exact, local symmetry by coupling the difference B−L to an Abelian gauge field. Gauge anomalies are cancelled by adding right-handed neutrinos νR. They are not sterile in this case, which forbids the Majorana term, but we arrange for a νR-mass by adding a Higgs-type 1-component complex scalar field. Thus we arrive at a well-motivated, modest extension of the Standard Model (SM). We investigate the field equations in the corresponding gauge-Higgs sector, involving both Higgs fields and the non-standard U(1) gauge field. This leads to a set of coupled, non-linear differential equations, which we solve numerically. We use cylindrical coordinates, thus focusing on the structures of cosmic strings. For a large variety of parameters, we identify the string profiles and energy densities. These profiles depend on the winding number of each of the Higgs fields. For our parameters, the characteristic string radii are below 10−3 fm, and the string tension is not ruled out by observations of the Cosmic Microwave Background or gravitational waves. As an amazing peculiarity, we discover - for high winding numbers - ``overshooting'' and ``co-axial'' profile functions. In the latter case, the profile of the standard Higgs field changes its sign near the core of the cosmic string.
Related
- Impact of cosmic evolution on the gravitational wave spectrum from cosmic strings
- Gravitational Waves and Nambu-Goldstone Bosons from Infrared-Finite Cosmic Strings
- The decay rate of metastable cosmic strings beyond the thin-string approximation
- Fermionic cosmic strings in dynamical Chern-Simons gravity
- Detection of cosmic strings by gravitational wave lensing. Predictions for Einstein Telescope
BibTeX
@misc{bietenholz2026nonstandard,
title = {{Non-standard cosmic strings with amazing profiles}},
author = {Wolfgang Bietenholz and José Antonio García-Hernández and Victor Muñoz-Vitelly},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.23920},
eprint = {2609.23920},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.23920},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Non-standard cosmic strings with amazing profiles
AU - Wolfgang Bietenholz
AU - José Antonio García-Hernández
AU - Victor Muñoz-Vitelly
PY - 2026
DA - 2026/09/20
PB - arXiv
DO - 10.48550/arxiv.2609.23920
UR - https://arxiv.org/abs/2609.23920
AB - It is an unnatural feature of the Standard Model that the difference between the baryon number B and the lepton number L is conserved, which implies an exact, global symmetry. We promote it to a naturally exact, local symmetry by coupling the difference B−L to an Abelian gauge field. Gauge anomalies are cancelled by adding right-handed neutrinos ν_R. They are not sterile in this case, which forbids the Majorana term, but we arrange for a ν_R-mass by adding a Higgs-type 1-component complex scalar field. Thus we arrive at a well-motivated, modest extension of the Standard Model (SM). We investigate the field equations in the corresponding gauge-Higgs sector, involving both Higgs fields and the non-standard U(1) gauge field. This leads to a set of coupled, non-linear differential equations, which we solve numerically. We use cylindrical coordinates, thus focusing on the structures of cosmic strings. For a large variety of parameters, we identify the string profiles and energy densities. These profiles depend on the winding number of each of the Higgs fields. For our parameters, the characteristic string radii are below 10^−3 fm, and the string tension is not ruled out by observations of the Cosmic Microwave Background or gravitational waves. As an amazing peculiarity, we discover - for high winding numbers - ``overshooting'' and ``co-axial'' profile functions. In the latter case, the profile of the standard Higgs field changes its sign near the core of the cosmic string.
ER -