Nonlinearity Analysis for Cosmological inflation with minimal and non-minimal coupling of scalar field from Horndeski theory for Special Cases: De Sitter Expansion and Decaying Scalar Field
G Hikmawan (1*), A Suroso (1,2), F P Zen (1,2)
1) Theoretical Physics Laboratory, THEPI Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganehsa 10 Bandung 40132, Indonesia
2) Indonesia Center of Theoretical and Mathematical Physics (ICTMP), Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132, Indonesia
Abstract
In this work, we consider De Sitter expansion and decaying scalar field in cosmological model with combination of minimal and non-minimal coupling of scalar field from Horndeski theory. As a continuity of the previous work, after the background solution and condition obtained, we continue the analysis to the nonlinearity aspect of perturbations via the spectral index of the perturbations. Spectral index of the perturbations and tensor to-scalar ratio of these special cases give sign of inflation model.
Keywords: Cosmology; Inflation; Horndeski
Topic: Theoretical High Energy Physics