Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics

We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of local U(1) string and stable composites, we simulate the collis...

Full description

Bibliographic Details
Main Authors: Bevis, Neil, Saffin, Paul M.
Format: Article
Published: American Physical Society 2008
Online Access:https://eprints.nottingham.ac.uk/42124/
_version_ 1848796424899133440
author Bevis, Neil
Saffin, Paul M.
author_facet Bevis, Neil
Saffin, Paul M.
author_sort Bevis, Neil
building Nottingham Research Data Repository
collection Online Access
description We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of local U(1) string and stable composites, we simulate the collision of two straight strings and investigate whether the dynamics matches that previously obtained using the Nambu-Goto action, which is not strictly valid close to the junction. We find that the Nambu-Goto action performs only moderately well at predicting when the collision results in the formation of a pair of Y-junctions (with a composite string connecting them). However, we find that when they do form, the late time dynamics matches those of the Nambu-Goto approximation very closely. We also see little radiative emission from the Y-junction system, which suggests that radiative decay due to bridge formation does not appear to be a means via which a cosmological network of such string would rapidly lose energy.
first_indexed 2025-11-14T19:47:46Z
format Article
id nottingham-42124
institution University of Nottingham Malaysia Campus
institution_category Local University
last_indexed 2025-11-14T19:47:46Z
publishDate 2008
publisher American Physical Society
recordtype eprints
repository_type Digital Repository
spelling nottingham-421242020-05-04T16:27:47Z https://eprints.nottingham.ac.uk/42124/ Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics Bevis, Neil Saffin, Paul M. We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of local U(1) string and stable composites, we simulate the collision of two straight strings and investigate whether the dynamics matches that previously obtained using the Nambu-Goto action, which is not strictly valid close to the junction. We find that the Nambu-Goto action performs only moderately well at predicting when the collision results in the formation of a pair of Y-junctions (with a composite string connecting them). However, we find that when they do form, the late time dynamics matches those of the Nambu-Goto approximation very closely. We also see little radiative emission from the Y-junction system, which suggests that radiative decay due to bridge formation does not appear to be a means via which a cosmological network of such string would rapidly lose energy. American Physical Society 2008-07-02 Article PeerReviewed Bevis, Neil and Saffin, Paul M. (2008) Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics. Physical Review D, 78 (2). 023503. ISSN 2470-0029 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.78.023503 doi:10.1103/PhysRevD.78.023503 doi:10.1103/PhysRevD.78.023503
spellingShingle Bevis, Neil
Saffin, Paul M.
Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title_full Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title_fullStr Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title_full_unstemmed Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title_short Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics
title_sort cosmic string y-junctions: a comparison between field theoretic and nambu-goto dynamics
url https://eprints.nottingham.ac.uk/42124/
https://eprints.nottingham.ac.uk/42124/
https://eprints.nottingham.ac.uk/42124/