# What is the relationship between the cosmological constant and Hubble's constant?

Jul 7, 2016

Hobble constant ${H}_{o}$ is based on Doppler effect. Cosmological constant $\Lambda$ is a relativity-related arbitrary constant. Both help estimate the agr of our universe.

#### Explanation:

Doppler effect is that light emitted by a source is shifted by wave

length, when the source moves. In the determination of Hubble's

correlation constant ${H}_{o}$, this is the basis. In appropriate units, 1/${H}_{o}$

gives an estimate of the age of our universe. For example, if

${H}_{o} = 71$ km/sec/mega parsec, $\frac{1}{71} \to 13.8$ billion years, after

conversions of units for parity.

In the past few billions of years, it appears the rate of expansion

of our universe has changed.. Such changes are adopted in

cosmological constant, by making it arbitrary,, to admit both

expansion and contraction of our universe. This guides against

over.estimation.