Long wavelength limit of evolution of cosmological perturbations in the universe where scalar fields and fluids coexist

Abstract

We present the LWL formula which represents the long wavelengh limit of the solutions of evolution equations of cosmological perturbations in terms of the exactly homogeneous solutions in the most general case where multiple scalar fields and multiple perfect fluids coexist. We find the conserved quantity which has origin in the adiabatic decaying mode, and by regarding this quantity as the source term we determine the correction term which corrects the discrepancy between the exactly homogeneous perturbations and the $k\to 0$ limit of the evolutions of cosmological perturbations. This LWL formula is useful for investigating the evolutions of cosmological perturbations in the early stage of our universe such as reheating after inflation and the curvaton decay in the curvaton scenario. When we extract the long wavelength limits of evolutions of cosmological perturbations from the exactly homogeneos perturbations by the LWL formula, it is more convenient to describe the corresponding exactly homogeneous system with not the cosmological time but the scale factor as the evolution parameter. By applying the LWL formula to the reheating model and the curvaton model with multiple scalar fields and multiple radiation fluids, we obtain the S formula representing the final amplitude of the Bardeen parameter in terms of the initial adiabatic and isocurvature perturbations Keywords:cosmological perturbations,long wavelength limit,reheating,curvaton PACS number(s):98.80.Cq

arXiv commentPage:46

References in corpus (21)

• Towards the Theory of Reheating After Inflation
• Reheating after Inflation
• Universe Reheating after Inflation
• A new approach to the evolution of cosmological perturbations on large scales
• A new mechanism for generating density perturbations from inflation
• Super-Horizon Scale Dynamics of Multi-Scalar Inflation
• Large-scale curvature and entropy perturbations for multiple interacting fluids
• Parametric Amplification of Metric Fluctuations During Reheating in Two Field Models
• Massless Metric Preheating
• Cosmological perturbation with two scalar fields in reheating after inflation
• Density perturbations in the brane-world
• Evolution of cosmological perturbations in a stage dominated by an oscillatory scalar field
• Fate of oscillating scalar fields in the thermal bath and their cosmological implications
• Backreaction and the Parametric Resonance of Cosmological Fluctuations
• Evolution of Cosmological Perturbations during Reheating
• Curvature and isocurvature perturbations in a three-fluid model of curvaton decay
• Evolution of Cosmological Perturbations in the Long Wavelength Limit
• Gravitational waves in cosmological models of Hořava-Witten theory
• Chaotic dynamics in preheating after inflation
• Evolution of Cosmological Perturbations in the Universe dominated by Multiple Scalar Fields
• Evolution of Cosmological Perturbations in the Universe dominated by Resonant Scalar Fields

Cited by in corpus (5)

• Constraints on scalar and tensor perturbations in phenomenological and two-field inflation models: Bayesian evidences for primordial isocurvature and tensor modes
• Constraints on neutrino density and velocity isocurvature modes from WMAP-9 data
• Long wavelength limit of evolution of nonlinear cosmological perturbations
• Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion
• Construction and applications of the manifestly gauge invariant expressions of the solutions of the cosmological perturbation theory