cosmology

Cosmology is the study of the origin, the evolution, and the eventual fate of the universe. The term physical cosmology can be used to specify that physical science is the basis of your study. The term cosmos is a synonym for universe.

Current physical cosmology is based on the cosmological principle that sufficiently basic natural laws that apply here also apply to the far reaches of the universe, i.e., objects observed at a distance are assumed to follow such laws. General relativity plays a big role in current cosmological theory (relativistic cosmology). Current thought places the beginning of the universe at about 13.8 billion years ago, the term for this beginning being the Big Bang. The Lambda-CDM model is the current favored detailed model, much contemporary cosmological research effort being to pin down its details through observation, and to explore its problems, such discrepancies with observation, and to explore possible improvements.

The adjective cosmological is often used to mean "involving distances or times when cosmology is relevant", i.e., the early universe and distances at which only the early universe is visible because of the time required for the electromagnetic radiation to reach us (cosmological distances). The adjective cosmic has the same meaning (at least roughly) and often which is used seems mere preference, or habit regarding a particular phrase, e.g., cosmological distance versus cosmic distance scale.

A cosmogony is a theory or model of the origin of the universe.