Simple Predictions from Multifield Inflationary Models

Citations Over TimeTop 10% of 2014 papers

Abstract

We explore whether multifield inflationary models make unambiguous predictions for fundamental cosmological observables. Focusing on N-quadratic inflation, we numerically evaluate the full perturbation equations for models with 2, 3, and O(100) fields, using several distinct methods for specifying the initial values of the background fields. All scenarios are highly predictive, with the probability distribution functions of the cosmological observables becoming more sharply peaked as N increases. For N=100 fields, 95% of our Monte Carlo samples fall in the ranges ns∈(0.9455,0.9534), α∈(-9.741,-7.047)×10-4, r∈(0.1445,0.1449), and riso∈(0.02137,3.510)×10-3 for the spectral index, running, tensor-to-scalar ratio, and isocurvature-to-adiabatic ratio, respectively. The expected amplitude of isocurvature perturbations grows with N, raising the possibility that many-field models may be sensitive to postinflationary physics and suggesting new avenues for testing these scenarios.

Related Papers

• → Optimal measurements in quantum mechanics(2005)29 cited
• → The Role of Observables and Non-observables in Chemistry: A Critique of Chemical Language(2006)24 cited
• → Estimating the expectation values of spin-1/2 observables with finite resources(2007)18 cited
• → CALCULATION OF EXPECTED VALUES OF OBSERVABLES IN SOME PROBLEMS OF STATISTICAL GEOMORPHOLOGY(1971)1 cited
• → A Canonical form of Completely Uniformly Locally Weakly Observable Multi-output Nonlinear Systems(2006)