Topological defects and nano-Hz gravitational waves in aligned axion models

Tetsutaro Higaki, Kwang Sik Jeong, Naoya Kitajima, Toyokazu Sekiguchi, Fuminobu Takahashi

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Abstract: We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.

Original languageEnglish
Article number44
JournalJournal of High Energy Physics
Volume2016
Issue number8
DOIs
Publication statusPublished - 2016 Aug 1

Fingerprint

gravitational waves
strings
quantum chromodynamics
defects
scalars
decay
pulsars
time measurement
symmetry

Keywords

  • Beyond Standard Model
  • Cosmology of Theories beyond the SM

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Topological defects and nano-Hz gravitational waves in aligned axion models. / Higaki, Tetsutaro; Jeong, Kwang Sik; Kitajima, Naoya; Sekiguchi, Toyokazu; Takahashi, Fuminobu.

In: Journal of High Energy Physics, Vol. 2016, No. 8, 44, 01.08.2016.

Research output: Contribution to journalArticle

Higaki, Tetsutaro ; Jeong, Kwang Sik ; Kitajima, Naoya ; Sekiguchi, Toyokazu ; Takahashi, Fuminobu. / Topological defects and nano-Hz gravitational waves in aligned axion models. In: Journal of High Energy Physics. 2016 ; Vol. 2016, No. 8.
@article{8a75106ab88f4e048e9f7019b5e90ee9,
title = "Topological defects and nano-Hz gravitational waves in aligned axion models",
abstract = "Abstract: We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.",
keywords = "Beyond Standard Model, Cosmology of Theories beyond the SM",
author = "Tetsutaro Higaki and Jeong, {Kwang Sik} and Naoya Kitajima and Toyokazu Sekiguchi and Fuminobu Takahashi",
year = "2016",
month = "8",
day = "1",
doi = "10.1007/JHEP08(2016)044",
language = "English",
volume = "2016",
journal = "Journal of High Energy Physics",
issn = "1126-6708",
publisher = "Springer Verlag",
number = "8",

}

TY - JOUR

T1 - Topological defects and nano-Hz gravitational waves in aligned axion models

AU - Higaki, Tetsutaro

AU - Jeong, Kwang Sik

AU - Kitajima, Naoya

AU - Sekiguchi, Toyokazu

AU - Takahashi, Fuminobu

PY - 2016/8/1

Y1 - 2016/8/1

N2 - Abstract: We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.

AB - Abstract: We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.

KW - Beyond Standard Model

KW - Cosmology of Theories beyond the SM

UR - http://www.scopus.com/inward/record.url?scp=84981215120&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84981215120&partnerID=8YFLogxK

U2 - 10.1007/JHEP08(2016)044

DO - 10.1007/JHEP08(2016)044

M3 - Article

AN - SCOPUS:84981215120

VL - 2016

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1126-6708

IS - 8

M1 - 44

ER -