Rapid expansion of the universe at its early stages of development (at around 10-36 seconds after the Big Bang).
The Inflation Theory was developed in 1980 by Alan Guth, Andrei Linde, Paul Steinhardt, and Andy Albrecht and attempted to account for phenomena that could not be explained by the Big Bang Theory (the Horizon Problem, the Flatness Problem and the Monopole Problem). Nowadays, the Inflation Theory is considered to be an extension of the Big Bang Theory.
