New Inflation vs. Chaotic Inflation, Higher Degree Potentials and the Reconstruction Program in light of WMAP3

Abstract

The CMB power spectra are studied for different families of single field new and chaotic inflation models in the effective field theory approach to inflation. We implement a systematic expansion in 1/N_e where N_e ~ 50 is the number of e-folds before the end of inflation. We study the dependence of the observables (n_s, r and dn_s/d\ln k) on the degree of the potential (2 n) and confront them to the WMAP3 and large scale structure data: this shows in general that fourth degree potentials (n=2) provide the best fit to the data; the window of consistency with the WMAP3 and LSS data narrows for growing n. New inflation models yield a good fit to the r and n_s data in a wide range of field and parameter space. Small field inflation yields r<0.16 while large field inflation yields r>0.16 (for N_e=50). All members of the new inflation family predict a small but negative running -4(n+1)10^{-4}< dn_s/d\ln k <-2 10^{-4}. A reconstruction program is carried out suggesting quite generallythat for n_s consistent with the WMAP3 and LSS data and r<0.1 the symmetry breaking scale for new inflation is |ϕ_0| ~ 10 M_{Pl} while the field scale at Hubble crossing is |ϕ_{50}| ~ M_{Pl}.The family of chaotic models feature r>0.16 (for N_e=50) and only a restricted subset of chaotic models are consistent with the combined WMAP3 bounds on r, n_s,dn_s/d\ln k with a narrow window in field amplitude around |ϕ_{50}| ~ 15 M_{Pl}.A measurement of r<0.16 (for N_e =50) will distinctly rule out a large class of chaotic scenarios and will favor new inflationary models. As a general consequence, new inflation emerges more favoured than chaotic inflation.

arXiv comment19 pages, 18 figures. Minor additions. Matches version published in Phys. Rev. D

References in corpus (21)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• Cosmological parameters from SDSS and WMAP
• The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Inflation
• Cosmological parameter analysis including SDSS Ly-alpha forest and galaxy bias: constraints on the primordial spectrum of fluctuations, neutrino mass, and dark energy
• Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization
• Reconstructing the Inflaton Potential --- an Overview
• Formalising the Slow-Roll Approximation in Inflation
• Inflation after WMAP3: Confronting the Slow-Roll and Exact Power Spectra with CMB Data
• Cosmological parameters from CMB measurements and the final 2dFGRS power spectrum
• Inflation: flow, fixed points and observables to arbitrary order in slow roll
• Inflation model constraints from the Wilkinson Microwave Anisotropy Probe three-year data
• Kinematic Constraints to the Key Inflationary Observables
• Constraining slow-roll inflation with WMAP and 2dF
• Recovering the Inflationary Potential and Primordial Power Spectrum With a Slow Roll Prior: Methodology and Application to WMAP 3 Year Data
• Implications of a Running Spectral Index for Slow Roll Inflation
• Theoretical Uncertainties in Inflationary Predictions
• Constraints on the Inflationary Expansion from Three Year WMAP, small scale CMB anisotropies and Large Scale Structure Data Sets
• Microwave background constraints on inflationary parameters
• Single Field Inflation models allowed and ruled out by the three years WMAP data

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• Inflationary predictions of double-well, Coleman-Weinberg, and hilltop potentials with non-minimal coupling
• WMAP5 Observationnal Constraints on Braneworld New Inflation Model
• Unparticle-Higgs Mixing: MSW Resonances, See-saw Mechanism and Spinodal Instabilities