Non-Gaussianities in multifield inflation: Superhorizon evolution, adiabaticity, and the fate of f{sub NL}
- Theory Group, Department of Physics, University of Texas, Austin, Texas 78712 (United States) and Texas Cosmology Center, University of Texas, Austin, Texas 78712 (United States)
We explore the superhorizon generation of large f{sub NL} of the local form in two-field inflation. We calculate the two- and three-point observables in a general class of potentials which allow for an analytic treatment using the {delta}N formalism. Motivated by the conservation of the curvature perturbation outside the horizon in the adiabatic mode and also by the observed adiabaticity of the power spectrum, we follow the evolution of f{sub NL}{sup local} until it is driven into the adiabatic solution by passing through a phase of effectively single-field inflation. We find that, although large f{sub NL}{sup local} may be generated during inflation, such nongaussianities are transitory and will be exponentially damped as the cosmological fluctuations approach adiabaticity.
- OSTI ID:
- 21502560
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 83, Issue 10; Other Information: DOI: 10.1103/PhysRevD.83.103517; (c) 2011 American Institute of Physics; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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