Inflationary Cosmology: Progress and Problems

TL;DR

This paper provides a pedagogical overview of inflationary cosmology, discussing recent progress in reheating and perturbation theory, while also addressing fundamental problems and exploring new theoretical approaches like nonsingular universe models.

Contribution

It offers a concise introduction to inflationary cosmology, highlighting recent advances and proposing novel solutions to longstanding issues using higher derivative gravity and back-reaction analysis.

Findings

Progress in understanding reheating processes

Development of theories for cosmological perturbations

Proposals for nonsingular universe models

Abstract

These lecture notes intend to form a short pedagogical introduction to inflationary cosmology, highlighting selected areas of recent progress such as reheating and the theory of cosmological perturbations. Problems of principle for inflationary cosmology are pointed out, and some new attempts at solving them are indicated, including a nonsingular Universe construction by means of higher derivative terms in the gravitational action, and the study of back-reaction of cosmological perturbations.