Introduction to Cosmology

TL;DR

This paper provides an overview of modern cosmology, covering the big bang model, inflationary theory, density perturbations, and cosmic background radiation, highlighting recent theoretical developments.

Contribution

It summarizes the evolution of cosmological models from the big bang to inflation, including new insights into hybrid inflationary models and their implications.

Findings

Inflation resolves shortcomings of the big bang model.

Density perturbations explain structure formation.

Hybrid inflation models incorporate supersymmetry.

Abstract

The standard big bang cosmological model and the history of the early universe according to the grand unified theories of strong, weak and electromagnetic interactions are summarized. The shortcomings of big bang are discussed together with their resolution by inflationary cosmology. Inflation and the subsequent oscillation and decay of the inflaton field are studied. The density perturbations produced during inflation and their evolution during the matter dominated era are analyzed. The temperature fluctuations of the cosmic background radiation are summarized. Finally, the nonsupersymmetric as well as the supersymmetric hybrid inflationary model is described.