The quantum inflaton, primordial perturbations and CMB fluctuations

Abstract

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the dynamics of the (classical) cosmological metric. For chaotic inflation, the quantum treatment avoids the unnatural requirements of an initial state with all the energy in the zero mode. For new inflation it allows a consistent treatment of the explosive particle production due to spinodal instabilities. Quantum field inflation (under conditions that are the quantum analog of slow roll) leads, upon evolution, to the formation of a condensate starting a regime of effective classical inflation. We compute the primordial perturbations taking the dominant quantum effects into account. The results for the scalar, vector and tensor primordial perturbations are expressed in terms of the classical inflation results. For a N-component field in a O(N) symmetric model, adiabatic fluctuations dominate while isocurvature or entropy fluctuations are negligible. The results agree with the current WMAP observations and predict corrections to the power spectrum in classical inflation.Such corrections are estimated to be of the order of m^2/[N H^2] where m is the inflaton mass and H the Hubble constant at horizon crossing. This turns to be about 4% for the cosmologically relevant scales. This quantum field treatment of inflation provides the foundations to the classical inflation and permits to compute quantum corrections to it.

23 pages, no figures. Improved version to appear in Phys. Rev. D

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Cited by in corpus (10)

• Particle decay during inflation: self-decay of inflaton quantum fluctuations during slow roll
• The Effective Theory of Inflation in the Standard Model of the Universe and the CMB+LSS data analysis
• Clarifying Inflation Models: Slow-roll as an expansion in 1/N_{efolds}
• Quantum slow-roll and quantum fast-roll inflationary initial conditions: CMB quadrupole suppression and further effects on the low CMB multipoles
• Quantum quenches during inflation
• Out of equilibrium quantum field dynamics of an initial thermal state after a change in the external field
• The Classical and Quantum Inflaton: the Precise Inflationary Potential and Quantum Inflaton Decay after WMAP
• Clarifying Inflation Models: the Precise Inflationary Potential from Effective Field Theory and the WMAP data
• Out of equilibrium quantum field dynamics in external fields
• Quantum inflaton, primordial metric perturbations and CMB fluctuations