Non-Gaussian isocurvature perturbations from Goldstone modes generated during inflation

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.55.7415· OSTI ID:530242

Bucher, M ^[1]; Zhu, Y ^[1]

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1. Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

We investigate non-Gaussian isocurvature perturbations generated by the evolution of Goldstone modes during inflation. If a global symmetry is broken {ital before} inflation, the resulting Goldstone modes are disordered during inflation in a precise and predictable way. After inflation these Goldstone modes order themselves in a self-similar way, much as Goldstone modes in field ordering scenarios based on the Kibble mechanism. For (H{sub inf}{sup 2}/M{sub Pl}{sup 2}){approximately}10{sup {minus}6}, through their gravitational interaction these Goldstone modes generate density perturbations of approximately the right magnitude to explain the cosmic microwave background (CMB) anisotropy and seed the structure seen in the universe today. We point out that for the pattern of symmetry breaking in which a global U(1) is completely broken, the inflationary evolution of the Goldstone field may be treated as that of a massless scalar field. Unlike the more commonly discussed case in which a global U(1) is completely broken in a cosmological phase transition, in the inflationary case the production of defects can be made exponentially small, so that Goldstone field evolution is completely linear. In such a model non-Gaussian perturbations result because to lowest order density perturbations are sourced by products of Gaussian fields. Consequently, in this non-Gaussian model N-point correlations may be calculated by evaluating Feynman diagrams. We explore the issue of phase dispersion and conclude that this non-Gaussian model predicts Doppler peaks in the CMB anisotropy. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 530242
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 12 Vol. 55; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANISOTROPY
BACKGROUND RADIATION
CORRELATIONS
COSMIC RADIATION
COSMOLOGY
GLOBAL ANALYSIS
GOLDSTONE BOSONS
INFLATION
INFLATIONARY UNIVERSE
MICROWAVE RADIATION
PERTURBATION THEORY
SYMMETRY
U-1 GROUPS