Optimizing future experimental probes of inflation

Abstract

The discovery of many novel realizations of the inflationary universe paradigm has led to a degeneracy problem: many different inflationary Lagrangians generate the same perturbation spectra. Resolving this problem requires the future discovery of additional observables, beyond the scalar adiabatic and tensor two-point functions on CMB scales. One important source of degeneracy arises in models where the density perturbation is generated by a non-inflationary degree of freedom, for example, through curvatons or modulated reheating. We consider the curvaton scenario as representative of this class, and analyze the degeneracy with single field, canonical inflation that results if the curvaton goes undetected by future observations. We perform Monte Carlo potential reconstructions in the absence of distinguishing observables, such as non-Gaussiantities or isocurvature modes. The resulting degeneracy is considerable and the improved measurements of spectral parameters from future probes like CMBPol, offer little to better the situation. Given a degeneracy-breaking observation, the observables must still be inverted to obtain the inflationary potential, with different observations resulting in reconstructions of varying quality. We find that a future detection of isocurvature modes or a precision measurement of the tensor spectral index will enable the most successful reconstructions in the presence of curvatons.

21 pages, 8 figures, minor revisions, version to appear in PRD

References in corpus (88)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• k-Inflation
• Generating the curvature perturbation without an inflaton
• Hybrid Inflation
• False Vacuum Inflation with Einstein Gravity
• DBI in the Sky
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• Possibility of Direct Measurement of the Acceleration of the Universe Using 0.1 Hz Band Laser Interferometer Gravitational Wave Antenna in Space
• Monodromy in the CMB: Gravity Waves and String Inflation
• Effects of Cosmological Moduli Fields on Cosmic Microwave Background
• Reconstructing the Inflaton Potential --- an Overview
• Gravity Waves and Linear Inflation from Axion Monodromy
• What would we learn by detecting a gravitational wave signal in the cosmic microwave background anisotropy?
• Scalar Speed Limits and Cosmology: Acceleration from D-cceleration
• The primordial density perturbation in the curvaton scenario
• Nongaussian Isocurvature Perturbations from Inflation
• Formalising the Slow-Roll Approximation in Inflation
• A more accurate analytic calculation of the spectrum of cosmological perturbations produced during inflation
• The inflationary prediction for primordial non-gaussianity
• A new mechanism for generating density perturbations from inflation
• Non-Gaussianity of the primordial perturbation in the curvaton model
• CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
• Detecting a gravitational-wave background with next-generation space interferometers
• On Non-Gaussianity in the Curvaton Scenario
• The Angular Trispectrum of the CMB
• Signatures of Short Distance Physics in the Cosmic Microwave Background
• An Observational Test of Two-field Inflation
• Direct detection of the inflationary gravitational wave background
• Primordial trispectrum from inflation
• Detecting a small perturbation through its non-Gaussianity
• Inflation: flow, fixed points and observables to arbitrary order in slow roll
• Inflation model constraints from the Wilkinson Microwave Anisotropy Probe three-year data
• The Angular Trispectra of CMB Temperature and Polarization
• Cosmic microwave background measurements can discriminate among inflation models
• Angular Trispectrum of CMB Temperature Anisotropy from Primordial Non-Gaussianity with the Full Radiation Transfer Function
• Reconstructing the Inflaton Potential---in Principle and in Practice
• The inflationary trispectrum
• Non-Gaussianity, Spectral Index and Tensor Modes in Mixed Inflaton and Curvaton Models
• Observational constraints on the curvaton model of inflation
• Non-linear isocurvature perturbations and non-Gaussianities
• Non-gaussianity from the second-order cosmological perturbation
• Kinematic Constraints to the Key Inflationary Observables
• Constraining Running Non-Gaussianity
• A numerical study of non-gaussianity in the curvaton scenario
• Scale dependence of local f_NL
• Mixed inflaton and curvaton perturbations
• Constraining Isocurvature Initial Conditions with WMAP 3-year data
• Considerations in optimizing CMB polarization experiments to constrain inflationary physics
• Models of inflation liberated by the curvaton hypothesis
• Constraining Isocurvature Perturbations with CMB Polarization
• WMAPping inflationary physics
• Large non-Gaussianity from two-component hybrid inflation
• Bounds on isocurvature perturbations from CMB and LSS data
• The Curvaton Web
• Non-Gaussianity from isocurvature perturbations
• Short Distance Physics and the Consistency Relation for Scalar and Tensor Fluctuations in the Inflationary Universe
• Monte Carlo reconstruction of the inflationary potential
• Reconstructing the Inflaton Potential---Perturbative Reconstruction to Second Order
• Lectures on inflation and cosmological perturbations
• Relaxing Constraints on Inflation Models with Curvaton
• The Lyth Bound Revisited
• A General Analysis of Non-Gaussianity from Isocurvature Perturbations
• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• Implications of the Curvaton on Inflationary Cosmology
• The initial conditions of the universe: how much isocurvature is allowed?
• Correlation analysis of stochastic gravitational wave background around 0.1-1Hz
• Cosmological Parameters Degeneracies and Non-Gaussian Halo Bias
• WMAP, neutrino degeneracy and non-Gaussianity constraints on isocurvature perturbations in the curvaton model of inflation
• The Lyth Bound and the End of Inflation
• Deciphering Inflation with Gravitational Waves: Cosmic Microwave Background Polarization vs. Direct Detection with Laser Interferometers
• Constraints on primordial isocurvature perturbations and spatial curvature by Bayesian model selection
• Scale-dependence of Non-Gaussianity in the Curvaton Model
• Non-Gaussianity and Baryonic Isocurvature Fluctuations in the Curvaton Scenario
• New constraints on the observable inflaton potential from WMAP and SDSS
• Cosmological parameters after WMAP5: forecasts for Planck and future galaxy surveys
• Detecting relic gravitational waves in the CMB: Optimal parameters and their constraints
• Circumventing the eta problem in building an inflationary model in string theory
• Non-Gaussianity from Isocurvature Perturbations : Analysis of Trispectrum
• Limits on primordial power spectrum resolution: An inflationary flow analysis
• The Detectability of Departures from the Inflationary Consistency Equation
• Cosmological Constraints on Isocurvature and Tensor Perturbations
• Tensors, non-Gaussianities, and the future of potential reconstruction
• Observational Signatures of Gravitational Couplings in DBI Inflation
• The Cosmic Microwave Background and Inflation Parameters
• Inflationary Potential from 21 cm Tomography and Planck
• Detecting Relic Gravitational Waves in the CMB: Comparison of Planck and Ground-based Experiments
• Cosmological Constraints on Rapid Roll Inflation

Cited by in corpus (22)

• Features and New Physical Scales in Primordial Observables: Theory and Observation
• Observational consequences of chaotic inflation with nonminimal coupling to gravity
• Encyclopaedia Curvatonis
• Cosmological constraints from CMB distortion
• Warm DBI Inflation
• Non-Gaussianities in Multifield Inflation: Superhorizon Evolution, Adiabaticity, and the Fate of fnl
• On the Unlikeliness of Multi-Field Inflation: Bounded Random Potentials and our Vacuum
• How much can we learn about the physics of inflation?
• Supercurvaton
• A grounded perspective on New Early Dark Energy using ACT, SPT, and BICEP/Keck
• Constraints on scalar and tensor perturbations in phenomenological and two-field inflation models: Bayesian evidences for primordial isocurvature and tensor modes
• Future constraints on neutrino isocurvature perturbations in the curvaton scenario
• Higher Order Corrections to the Primordial Gravitational Wave Spectrum and its Impact on Parameter Estimates for Inflation
• The Degeneracy Problem in Non-Canonical Inflation
• Inflaton or Curvaton? Constraints on Bimodal Primordial Spectra from Mixed Perturbations
• Identifying the inflaton with primordial gravitational waves
• What Planck does not tell us about inflation
• Testing inflationary consistency relations by the potential CMB observations
• Eternal Universes
• Horizon-preserving dualities and perturbations in non-canonical scalar field cosmologies
• A Brachistochrone Approach to Reconstruct the Inflaton Potential
• Hidden in the background: a local approach to CMB anomalies