Page "Non-standard cosmology" Paragraph 1

The term non-standard is applied to any cosmological theory that does not conform to the scientific consensus, but is not used in describing alternative models where no consensus has been reached, and is also used to describe theories that accept a " big bang " occurred but differ as to the detailed physics of the origin and evolution of the universe.

Because the term depends on the prevailing consensus, the meaning of the term changes over time.

For example, hot dark matter would not have been considered non-standard in 1990, but would be in 2010.

Conversely a non-zero cosmological constant resulting in an accelerating universe would have been considered non-standard in 1990, but is part of the standard cosmology in 2010.