Editing Cold dark matter (section)

{{short description|Hypothetical type of dark matter in physics}}

In [[Physical cosmology|cosmology]] and [[physics]], '''cold dark matter''' ('''CDM''') is a hypothetical type of [[dark matter]]. According to the current standard model of cosmology, [[Lambda-CDM model]], approximately 27% of the [[universe]] is dark matter and 68% is [[dark energy]], with only a small fraction being the ordinary [[baryonic matter]] that composes [[star]]s, [[planet]]s, and living organisms. ''Cold'' refers to the fact that the dark matter moves slowly compared to the [[speed of light]], giving it a vanishing [[Equation of state (cosmology)|equation of state]]. ''Dark'' indicates that it interacts very weakly with ordinary matter and [[electromagnetic radiation]].  Proposed candidates for CDM include [[weakly interacting massive particle]]s, [[primordial black hole]]s, and [[axion]]s.