Hybrid Inflation without Flat Directions and without Primordial Black Holes

Abstract

We investigate the possibility that the Universe may inflate due to moduli fields, corresponding to flat directions of supersymmetry, lifted by supergravity corrections. Using a hybrid-type potential we obtain a two-stage inflationary model. Depending on the curvature of the potential the first stage corresponds to a period of fast-roll inflation or a period of `locked' inflation, induced by an oscillating inflaton. This is followed by a second stage of fast-roll inflation. We demonstrate that these two consecutive inflationary phases result in enough total e-foldings to encompass the cosmological scales. Using natural values for the parameters (masses of order TeV and vacuum energy of the intermediate scale corresponding to gravity mediated supersymmetry breaking) we conclude that the $\eta$-problem of inflation is easily overcome. The greatest obstacle to our scenario is the possibility of copious production of cosmologically disastrous primordial black holes due to the phase transition switching from the first into the second stage of inflation. We study this problem in detail and show analytically that there is ample parameter space where these black holes do not form at all. To generate structure in the Universe we assume the presence of a curvaton field. Finally we also discuss the moduli problem and how it affects our considerations.

20 pages, LaTeX, 4 figures, added material and references, version submitted to journal

References in corpus (13)

• A new mechanism for generating density perturbations from inflation
• Cosmological Perturbations From Inhomogeneous Reheating, Freeze-Out, and Mass Domination
• The Curvaton as a Pseudo-Nambu-Goldstone Boson
• Curvaton Dynamics
• MSSM flat direction as a curvaton
• The Peccei-Quinn Field as Curvaton
• Challenges in generating density perturbations from a fluctuating inflaton coupling
• Resonant decay of flat directions
• MSSM curvaton in the gauge-mediated SUSY breaking
• Curvatons in Supersymmetric Models
• Low scale inflation and the curvaton mechanism
• Curvaton and QCD Axion in Supersymmetric Theories
• The end of locked inflation

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• Elliptic Inflation: Generating the curvature perturbation without slow-roll
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• Running spectral index from shooting-star moduli
• Ambiguity in running spectral index with an extra light field during inflation
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• Constraints on scalar-tensor theories from observations