Topic explanation

Standard explanation

Dark energy is the name given to the component or effect associated with the observed accelerated expansion of the universe.

Key points

• cosmological constant, Λ
• Cold Dark Matter
• ä > 0
• H=ȧ/a
• Cosmological Constant: Observations of distant Type Ia supernovae played a major historical role in revealing accelerated c
• Formula / Key Relation: Scale factor acceleration: ä > 0 indicates accelerated expansion. Hubble parameter: *H=ȧ/a
• Dark energy is the term used for the phenomenon/component associated with accelerated expansion.

Labelled diagram