ABSTRACT
Inflation provides an intriguing explanation for both the horizon and flatness problems, which makes it an interesting theory already. However it does more than that. It also provides an astounding explanation for the density variations in the early universe that eventually give rise to galaxy formation. The uncertainty in the energy at any point in the field is related to the uncertainty in the length of time that inflation has been taking place in that region of the universe. The density variations that give rise to temperature fluctuations in the background should have the characteristic arrangement predicted by inflation. The first perturbations to form early in the inflationary period grew to enormous sizes and the Hubble horizon did not catch them by the time recombination took place. The success of inflation and the use of quantum fluctuations in the Higgs field to explain the density fluctuations have spurred physicists to even greater ambitions.
