ANALYSIS OF GRAVITATIONALWAVES FROM INFLATION MODEL WITH MINIMAL, NON-MINIMAL, AND NON-MINIMAL DERIVATIVE COUPLING OF SCALAR FIELD FROM HORNDESKI THEORY

• Main Author: Zhahir Djogama, M.
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55031
• Institution: Institut Teknologi Bandung

Inflation theory is a theory that provide solutions for problems in cosmology, horizon problem and flatness problem. Gravitational waves production in inflationary scenario caused by tensor perturbation is a probe of inflation. The study of observational signatures of primordial GW provide not only a way to probe the general inflationary paradigm, but also to discriminate in detail among specific models. In this research, we use inflation model with minimal, non-minimal, and non-minimal derivative coupling of scalar field without potential from Horndeski Theory. From this model, we calculate scalar and tensor perturbation equations and then obtain its equation of gravitational waves, power spectrum for each perturbation mode and tensor-to-scalar ratio. Spectral indices and tensor-to-scalar ratio nearly scale-invariant and agree with observational data for some H0; z , and x . Gravitational waves remain constant during inflation and start oscillating when its modes re-enter the horizon. Energy of this gravitational waves predicted to be scale-invariant for modes that re-enter horizon during radiation dominated era and rises toward lower frequencies.