Modulation of the waterfall by a gauge field

Journal Article · Tue Jan 01 04:00:00 EST 2013 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2013/01/031· OSTI ID:22279623

Lyth, David H. ^[1]; Karčiauskas, Mindaugas ^[2]

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1. Consortium for Fundamental Physics, Cosmology and Astroparticle Group, Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)
2. CAFPE and Departamento de Física Teórica y del Cosmos, Universidad de Granada, Granada-18071 (Spain)

We present the first complete calculation of the curvature perturbation generated during the hybrid inflation waterfall, caused by the coupling of the waterfall field to a gauge field A whose kinetic function f{sup 2} depends on the inflaton field. We impose an upper bound on the field A≡fA which ensures that it has a negligible effect before the waterfall. We confirm the claim of Soda and Yokoyama, that the perturbation δB generates a statistically anisotropic spectrum and bispectrum, which could easily be observable. We also discover a new phenomenon, whereby the time-dependent 'varyon' field B causes the inflaton contribution to vary during the waterfall. The varyon mechanism might be implemented also with a scalar field and might not involve the waterfall.

• OSTI ID: 22279623
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2013; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
ASTROPHYSICS
COSMOLOGY
COUPLING
ENERGY SPECTRA
GAUGE INVARIANCE
INFLATIONARY UNIVERSE
INFLATONS
MODULATION
PERTURBATION THEORY
SCALAR FIELDS
TIME DEPENDENCE