Domain wall and isocurvature perturbation problems in axion models

Journal Article · Fri Nov 01 04:00:00 EDT 2013 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2013/11/030· OSTI ID:22369928

Kawasaki, Masahiro; Yoshino, Kazuyoshi ^[1]

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1. Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan)

Axion models have two serious cosmological problems, domain wall and isocurvature perturbation problems. In order to solve these problems we investigate the Linde's model in which the field value of the Peccei-Quinn (PQ) scalar is large during inflation. In this model the fluctuations of the PQ field grow after inflation through the parametric resonance and stable axionic strings may be produced, which results in the domain wall problem. We study formation of axionic strings using lattice simulations. It is found that in chaotic inflation the axion model is free from both the domain wall and the isocurvature perturbation problems if the initial misalignment angle θ{sub a} is smaller than O(10{sup −2}). Furthermore, axions can also account for the dark matter for the breaking scale v ≅ 10{sup 12−16} GeV and the Hubble parameter during inflation H{sub inf}∼<10{sup 11−12} GeV in general inflation models.

• OSTI ID: 22369928
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 11 Vol. 2013; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AXIONS
CHAOS THEORY
DISTURBANCES
GEV RANGE
INFLATIONARY UNIVERSE
NONLUMINOUS MATTER
PERTURBATION THEORY
WALLS