Spontaneous creation of almost scale-free density perturbations in an inflationary universe
The creation and evolution of energy-density perturbations are analyzed for the ''new inflationary universe'' scenario proposed by Linde, and Albrecht and Steinhardt. According to the scenario, the Universe underwent a strongly first-order phase transition and entered a ''de Sitter phase'' of exponential expansion during which all previously existing energy-density perturbations expanded to distance scales very large compared to the size of our observable Universe. The existence of an event horizon during the de Sitter phase gives rise to zero-point fluctuations in the scalar field phi, whose slowly growing expectation value signals the transition to the spontaneous-symmetry-breaking (SSB) phase of a grand unified theory (GUT). The fluctuations in phi are created on small distance scales and expanded to large scales, eventually giving rise to an almost scale-free spectrum of adiabatic density perturbations (the so-called Zel'dovich spectrum).For the simplest model of ''new inflation,'' that based on an SU(5) GUT with Coleman-Weinberg SSB, phi-dot(t/sub 1/)<>1: in obvious conflict with the large-scale isotropy of the microwave background. One remedy for this is a model in which the inflation occurs when phi-dot(t/sub 1/)>>H/sup 2/. We analyze a supersymmetric model which has this feature, and show that a value of deltarho/rhoVertical Bar/sub H/ approx. =10/sup -4/--10/sup -3/ on all observable scales is not implausible.
- Research Organization:
- Department of Physics, University of Washington, Seattle, Washington 98195
- OSTI ID:
- 5651136
- Journal Information:
- Phys. Rev. D; (United States), Vol. 28:4
- Country of Publication:
- United States
- Language:
- English
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