The second model agrees with the Big Bang Theory. It states that when the universe began, all matter was located within a specific region of space. An explosion occurred, sending matter forcibly outward. However, the Oscillating-Universe Theory states that the universe undergoes periods of expansion and contraction.
Eternal inflation is a hypothetical inflationary universe model, which is itself an outgrowth or extension of the Big Bang theory. According to eternal inflation, the inflationary phase of the universe's expansion lasts forever throughout most of the universe.
