In "High Energy Physics and Cosmology", 1999, eds. A. Masiero, G. Senjanovic, and A. Smirnov


AN INTRODUCTION TO COSMOLOGICAL INFLATION

Andrew R. Liddle


Astronomy Centre, University of Sussex, Brighton BN1 9QJ, U. K.
and
Astrophysics Group, The Blackett Laboratory, Imperial College,
London SW7 2BZ, U. K. (present address)


Abstract. An introductory account is given of the inflationary cosmology, which postulates a period of accelerated expansion during the Universe's earliest stages. The historical motivation is briefly outlined, and the modelling of the inflationary epoch explained. The most important aspect of inflation is that it provides a possible model for the origin of structure in the Universe, and key results are reviewed, along with a discussion of the current observational situation and outlook.


Table of Contents

OVERVIEW

BIG BANG PROBLEMS AND THE IDEA OF INFLATION
A hot big bang reminder
Equations of motion
Standard cosmological solutions
Critical density and the density parameter
Characteristic scales and horizons
Redshift and temperature
The history of the Universe

PROBLEMS WITH THE BIG BANG
The flatness problem
The horizon problem
The monopole problem (and other relics)

THE IDEA OF INFLATION
The flatness problem
Relic abundances
The horizon problem and homogeneity

MODELLING THE INFLATIONARY EXPANSION
Scalar fields and their potentials
Equations of motion and solutions
The relation between inflation and slow-roll
The amount of inflation
A worked example: polynomial chaotic inflation
Reheating after inflation
The range of inflation models
Chaotic inflation models
Multi-field theories
Beyond general relativity
Open inflation
Recap

DENSITY PERTURBATIONS AND GRAVITATIONAL WAVES
Production during inflation
A worked example
Observational consequences
Testing the idea of inflation

THE INFLATIONARY ORIGIN OF STRUCTURE
The parameters
The inflationary energy scale
Beyond the energy scale

SUMMARY

REFERENCES

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