Modulated Perturbations from Instant Preheating after new Ekpyrosis

Abstract

We present a mechanism to transfer the spectrum of perturbations in a scalar isocurvature field $\xi$ onto the matter content in the radiation era via modulated, instant preheating after ekpyrosis. In this setup, $\xi$ determines the coupling constant relevant for the decay of a preheat matter field into Fermions. The resulting power spectrum is scale invariant if $\xi$ remains close to a scaling solution in new ekpyrotic models of the universe; by construction the spectrum is independent of the detailed physics near the bounce. The process differs from the curvaton mechanism, which has been used recently to revive the ekpyrotic scenario, in that no peculiar behavior of $\xi$ shortly before or during the bounce is needed. In addition, a concrete and efficient realization of reheating after ekpyrosis is provided; this mechanism is not tied to ekpyrotic models, but could equally well be used in other setups, for instance inflationary ones. We estimate non-Gaussianities and find no additional contributions in the most simple realizations, in contrast to models using the curvaton mechanism.

21 pages; v2 references added, minor clarifications

References in corpus (77)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Towards the Theory of Reheating After Inflation
• Reheating after Inflation
• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang
• Generating the curvature perturbation without an inflaton
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Inflation Dynamics and Reheating
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• Universe Reheating after Inflation
• Cosmic Evolution in a Cyclic Universe
• A general proof of the conservation of the curvature perturbation
• Adiabatic and entropy perturbations from inflation
• From Big Crunch to Big Bang
• The inflationary prediction for primordial non-gaussianity
• A new mechanism for generating density perturbations from inflation
• Inflationary Cosmology
• Non-Gaussianity of the primordial perturbation in the curvaton model
• Limits on non-Gaussianities from WMAP data
• New Ekpyrotic Cosmology
• Primordial non-gaussianities from multiple-field inflation
• Non-Gaussianities in two-field inflation
• Beauty is Attractive: Moduli Trapping at Enhanced Symmetry Points
• Non-Gaussianities in models with a varying inflaton decay rate
• Non-Gaussianity in the modulated reheating scenario
• String Gas Cosmology
• Primordial trispectrum from inflation
• Generating Ekpyrotic Curvature Perturbations Before the Big Bang
• Generating the curvature perturbation at the end of inflation
• On matching conditions for cosmological perturbations
• The Separate Universe Approach and the Evolution of Nonlinear Superhorizon Cosmological Perturbations
• A smooth bouncing cosmology with scale invariant spectrum
• Inflation and Preheating in NO models
• Probing String Theory with Modulated Cosmological Fluctuations
• Conserved cosmological perturbations
• Non-Gaussianities in Multi-field Inflation
• On the Spectrum of Fluctuations in an Effective Field Theory of the Ekpyrotic Universe
• Limits on f_NL parameters from WMAP 3yr data
• Primordial Non-Gaussianity and Analytical Formula for Minkowski Functionals of the Cosmic Microwave Background and Large-scale Structure
• Adiabatic perturbations in pre big bang models: matching conditions and scale invariance
• Moduli Stabilization with the String Higgs Effect
• Modulated fluctuations from hybrid inflation
• Perturbations in bouncing cosmologies: dynamical attractor vs scale invariance
• Non-Gaussianities from ekpyrotic collapse with multiple fields
• Isocurvature perturbations in the Ekpyrotic universe
• Radion Stabilization by Stringy Effects in General Relativity
• The spectrum of cosmological perturbations produced by a multi-component inflaton to second order in the slow-roll approximation
• Ekpyrotic collapse with multiple fields
• Diagrammatic approach to non-Gaussianity from inflation
• On the Initial Conditions in New Ekpyrotic Cosmology
• Challenges in generating density perturbations from a fluctuating inflaton coupling
• Curvature perturbations from ekpyrotic collapse with multiple fields
• Scale-invariance in expanding and contracting universes from two-field models
• Non-Gaussianities in N-flation
• Colliding Branes in Heterotic M-theory
• Evolution of primordial perturbations and a fluctuating decay rate
• Scalar perturbations in regular two-component bouncing cosmologies
• Spectra of primordial fluctuations in two-perfect-fluid regular bounces
• Cosmic Perturbations Through the Cyclic Ages
• Dilaton Dynamics from Production of Tensionless Membranes
• Large-scale curvature perturbations with spatial and time variations of the inflaton decay rate
• Regular two-component bouncing cosmologies and perturbations therein
• Cosmological Moduli Dynamics
• Bouncing Negative-Tension Branes
• Perturbations in a Bouncing Brane Model
• Scenarios of modulated perturbations
• On the Transfer of Metric Fluctuations when Extra Dimensions Bounce or Stabilize
• Effective Actions for Heterotic M-Theory
• Scale-invariant Perturbations from Chaotic Inflation
• Cosmological density perturbations from perturbed couplings
• Perturbations in a regular bouncing Universe
• Generating the primordial curvature perturbations in preheating
• A Note on Perturbations During a Regular Bounce
• Inhomogeneous reheating scenario with low scale inflation and/or MSSM flat directions
• Light Scalars and the Generation of Density Perturbations During Preheating or Inflaton Decay
• Generating cosmological perturbations with mass variations
• Predictions of Dynamically Emerging Brane Inflation Models

Cited by in corpus (29)

• Nonperturbative Dynamics Of Reheating After Inflation: A Review
• Ekpyrotic and Cyclic Cosmology
• Review of local non-Gaussianity from multi-field inflation
• A Cosmological Super-Bounce
• Scale-dependent non-Gaussianity probes inflationary physics
• Local non-Gaussianity from inflation
• Non-Gaussian Density Fluctuations from Entropically Generated Curvature Perturbations in Ekpyrotic Models
• Non-Gaussianity beyond slow roll in multi-field inflation
• Intuitive understanding of non-gaussianity in ekpyrotic and cyclic models
• Non-Singular Bouncing Cosmology: Consistency of the Effective Description
• Ekpyrotic Non-Gaussianity -- A Review
• Multifield Cosmological Perturbations at Third Order and the Ekpyrotic Trispectrum
• Preheating and the non-gaussianity of the curvature perturbation
• Note on the production of scale-invariant entropy perturbation in the Ekpyrotic universe
• A general mechanism for producing scale-invariant perturbations and small non-Gaussianity in ekpyrotic models
• Ekpyrotic Perturbations With Small Non-Gaussian Corrections
• Constraints on generating the primordial curvature perturbation and non-Gaussianity from instant preheating
• On Non-Gaussianities in Multi-Field Inflation (N fields): Bi- and Tri-spectra beyond Slow-Roll
• Ekpyrotic loop quantum cosmology
• Reheating and Dark Matter Freeze-in in the Higgs-$R^2$ Inflation Model
• Quantum Circuit Complexity of Primordial Perturbations
• Fingerprints of a Non-Inflationary Universe from Massive Fields
• Particle Production during Inflation in Light of PLANCK
• Cuscuton Bounce Beyond the Linear Regime: Bispectrum and Strong Coupling Constraints
• Affleck-Dine baryogenesis with modulated reheating
• Tilted Ekpyrosis
• Entropic mechanisms with generalized scalar fields in the Ekpyrotic universe
• Curvature perturbations from kinetic preheating after $\alpha$-attractor inflation
• Inhomogeneous Reheating Scenario with DBI fields