Glossary term: Accelerating Universe

Description: In cosmology, four potential models have been proposed for the expansion of the Universe – one of them is an accelerating universe. Measurements of the light from a particular class of exploding star (Type Ia supernovae), located in very distant galaxies reveal that they are fainter than expected. The observational data matches the model of an accelerating universe, therefore providing indirect evidence that the rate at which the Universe is expanding is increasing. This phenomenon is occurring on the largest scales of clusters of galaxies, rather than in individual gravitationally bound galaxies. The accelerated expansion of the Universe is attributed to dark energy. Further evidence providing support for an accelerating Universe model is the cosmic microwave background (CMB) radiation.

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Term and definition status: This term and its definition is still awaiting approval

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