Hamilton–Jacobi approach for quasi-exponential inflation: predictions and constraints after Planck 2015 results

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2017-03, Vol.77 (3), p.1-10, Article 142
• Main Author: Videla, Nelson
• Format: Article
• Language: English
• Subjects: Astronomical models; Astronomy; Astrophysics and Cosmology; Dynamics; Elementary Particles; Hadrons; Heavy Ions; Inflation; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Theoretical Physics; String Theory; Universe
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-017-4711-2

In the present work we study the consequences of considering an inflationary universe model in which the Hubble rate has a quasi-exponential dependence in the inflaton field, given by H ( ϕ ) = H inf exp [ ϕ m p p 1 + ϕ m p ] . We analyze the inflation dynamics under the Hamilton–Jacobi approach, which allows us to consider H ( ϕ ) , rather than V ( ϕ ) , as the fundamental quantity to be specified. By comparing the theoretical predictions of the model together with the allowed contour plots in the n s - r plane and the amplitude of primordial scalar perturbations from the latest Planck data, the parameters charactering this model are constrained. The model predicts values for the tensor-to-scalar ratio r and for the running of the scalar spectral index d n s / d ln k consistent with the current bounds imposed by Planck, and we conclude that the model is viable.