inflationary universe

inflationary universe A variation on the Big Bang theory that includes a period of accelerated expansion in its early stages. In this model, energy is released during a so-called phase transition about 10⁻³⁵ s after the Big Bang, similar to the release of latent heat as a liquid freezes. The energy released acts in the same way as a cosmological constant term and drives the Universe to expand much faster than in the standard Friedmann models. The ultra-rapid expansion stretches out any primordial ‘wrinkles’ in the curvature of spacetime, rendering the Universe almost smooth and isotropic on the scales we can observe. Another feature of this theory is that it produces minute fluctuations in the density of the Universe which may be the seeds of galaxy formation. Recent observations of the cosmic background radiation imply that the curvature of space‐time is close to zero, which provides some support for the theory.