Reconstruction of Inflation Models

TL;DR

This paper reconstructs various inflationary models using observational data, including scalar field, fluid cosmology, and modified gravity, recovering known models and proposing new solutions for early universe acceleration.

Contribution

It introduces a unified reconstruction approach for inflation models from observational parameters, encompassing scalar, fluid, and modified gravity theories, with exact solutions.

Findings

Recovered R^2-inflation in Jordan and Einstein frames

Reconstructed massive scalar inflaton and inhomogeneous fluid models

Proposed R^2 correction to Einstein gravity with exact early universe solution

Abstract

In this paper, we reconstruct viable inflationary models by starting from spectral index and tensor-to-scalar ratio from Planck observations. We analyze three different kinds of models: scalar field theories, fluid cosmology and f(R)-modified gravity. We recover the well known R^2-inflation in Jodan frame and Einstein frame representation, the massive scalar inflaton models and two models of inhomogeneous fluid. A model of R^2-correction to Einstein's gravity plus a "cosmological constant" with an exact solution for early time acceleration is reconstructed.