Hubble parameter

Từ điển Oxford Learners Wordfinder Dictionary

noun

(cosmology) the ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer;
the Hubble constant is not actually a constant, but is regarded as measuring the expansion rate today
• Syn:
Hubble's constant, Hubble constant, Hubble's parameter
• Topics:
cosmology, cosmogony, cosmogeny
• Hypernyms:
constant