Many-field Inflation: Universality or Prior Dependence?

Abstract

We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ the central limit theorem and the horizon crossing approximation to derive universal predictions. These include a specific dependence on the prior choice for initial conditions that has not been seen in previous studies. Our main focus is on quadratic inflation, for which the initial conditions statistics decouple from those of the mass distribution, while other monomials are also briefly discussed. We verify the validity of our calculations by comparing to full numerical simulations with 100 fields using the transport method.

arXiv commentv2 minor changes to match published version JCAP, 10+1 pages

References in corpus (23)

• Non-Gaussian features of primordial fluctuations in single field inflationary models
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• Formalising the Slow-Roll Approximation in Inflation
• N-flation
• Non-Gaussianities in two-field inflation
• Random Matrices and the Spectrum of N-flation
• Inflation models and observation
• Nflation: multi-field inflationary dynamics and perturbations
• Nflation: non-gaussianity in the horizon-crossing approximation
• Simple predictions from multifield inflationary models
• Inflationary perturbation theory is geometrical optics in phase space
• Moment transport equations for the primordial curvature perturbation
• On Perturbation Spectra of N-flation
• Gravitational wave consistency relations for multifield inflation
• Systematics of Axion Inflation in Calabi-Yau Hypersurfaces
• Simple emergent power spectra from complex inflationary physics
• Manyfield Inflation in Random Potentials
• Predicting a Prior for Planck
• Seven Lessons from Manyfield Inflation in Random Potentials
• Inflation in Multi-field Modified DBM Potentials
• Predictions in multifield models of inflation
• Initial conditions and sampling for multifield inflation
• Axion Landscape Cosmology

Cited by in corpus (6)

• Multifield inflation beyond $N_{\mathrm{field}}=2$: non-Gaussianities and single-field effective theory
• Constraining the impact of standard model phase transitions on primordial black holes
• (Slow-)Twisting inflationary attractors
• Multiscalar-torsion Cosmology: Exact and Analytic Solutions from Noether Symmetries
• Rapid-turn inflation in supergravity is rare and tachyonic
• Non-Gaussianity after many-field reheating