5.8. Recap

The main points of this long section were the following.

• Cosmological scalar fields, which were introduced long before inflation was thought of, provide a natural framework for inflation.
• Despite a wide range of motivations, most inflationary models are dynamically equivalent to general relativity plus a single scalar field with some potential V().
• Within this framework, solutions describing inflation are easily found. Indeed, for many of the properties (amount of expansion, for example), we do not even need to solve the equations of motion.

With this information under our belts, we are now able to discuss the strongest motivation for the inflationary cosmology - that it is able to provide an explanation for the origin of structure in the Universe.