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Title: Cosmological perturbations of axion with a dynamical decay constant

Abstract

A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay constant also has the effect of enhancing the small-scale axion isocurvature perturbations. The enhanced axion perturbations can even exceed the periodicity of the axion potential, and thus lead to the formation of axionic domain walls. Unlike the well-studied axionic walls, the walls produced from the enhanced perturbations are not bounded by cosmic strings, and thus would overclose the universe independently of the number of degenerate vacua along the axion potential.

Authors:
 [1];  [2];  [3];  [4]
  1. SISSA,Via Bonomea 265, 34136 Trieste (Italy)
  2. (Italy)
  3. Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)
  4. (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan)
Publication Date:
Sponsoring Org.:
SCOAP3, CERN, Geneva (Switzerland)
OSTI Identifier:
22572138
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2016; Journal Issue: 08; Other Information: PUBLISHER-ID: JCAP08(2016)056; OAI: oai:repo.scoap3.org:16915; cc-by Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AXIONS; COSMOLOGICAL INFLATION; DISTURBANCES; INFLATIONARY UNIVERSE; PARTICLE DECAY; PERTURBATION THEORY; POTENTIALS; QUANTUM CHROMODYNAMICS; RELICT RADIATION; STRING THEORY; TIME DEPENDENCE; VACUUM STATES

Citation Formats

Kobayashi, Takeshi, INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste, Takahashi, Fuminobu, and Kavli IPMU. Cosmological perturbations of axion with a dynamical decay constant. United States: N. p., 2016. Web. doi:10.1088/1475-7516/2016/08/056.
Kobayashi, Takeshi, INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste, Takahashi, Fuminobu, & Kavli IPMU. Cosmological perturbations of axion with a dynamical decay constant. United States. doi:10.1088/1475-7516/2016/08/056.
Kobayashi, Takeshi, INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste, Takahashi, Fuminobu, and Kavli IPMU. 2016. "Cosmological perturbations of axion with a dynamical decay constant". United States. doi:10.1088/1475-7516/2016/08/056.
@article{osti_22572138,
title = {Cosmological perturbations of axion with a dynamical decay constant},
author = {Kobayashi, Takeshi and INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste and Takahashi, Fuminobu and Kavli IPMU},
abstractNote = {A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay constant also has the effect of enhancing the small-scale axion isocurvature perturbations. The enhanced axion perturbations can even exceed the periodicity of the axion potential, and thus lead to the formation of axionic domain walls. Unlike the well-studied axionic walls, the walls produced from the enhanced perturbations are not bounded by cosmic strings, and thus would overclose the universe independently of the number of degenerate vacua along the axion potential.},
doi = {10.1088/1475-7516/2016/08/056},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 08,
volume = 2016,
place = {United States},
year = 2016,
month = 8
}
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