Which theory is more preferred about universe expansion?

[John Conner]

Hello

I want to know which theory is more preferable among astrophysicists about the current expansion of the universe? i mean between cosmological constant or quintessence or something else?

and one more thing. what represents the expansion in equations for examining long distances ( megaparsec level ) ? Q? hubble constant? cosmo constant? (and i mean the accelerating expansion. the parameter for accelerating space)

Edited June 27, 2019 by John Conner

[beecee]

4 hours ago, John Conner said:

Hello

I want to know which theory is more preferable among astrophysicists about the current expansion of the universe? i mean between cosmological constant or quintessence or something else?

and one more thing. what represents the expansion in equations for examining long distances ( megaparsec level ) ? Q? hubble constant? cosmo constant? (and i mean the accelerating expansion. the parameter for accelerating space)

The parameter for the acceleration in the expansion rate is termed DE...or Dark Energy, because as yet we just do not know specifically exactly the nature of it.

The theory most accepted, in fact overwhelmingly accepted, is the Big Bang. The observed expansion, along with the CMBR at a current 2.7K, and the abundance of H and He, lighter elements, and the large scale galactic structure are the four main pillars of the BB theory.

The addition of Inflation is seen as supporting other aspects such as the flatness and the isotropic nature of the observable universe.

[Strange]

7 hours ago, John Conner said:

I want to know which theory is more preferable among astrophysicists about the current expansion of the universe? i mean between cosmological constant or quintessence or something else?

Just wanted to clarify: your question is (appears to be) about the accelerating expansion, not expansion. 

[John Conner]

5 hours ago, Strange said:

Just wanted to clarify: your question is (appears to be) about the accelerating expansion, not expansion. 

Yes. I said current but it wasn't accurate.

8 hours ago, beecee said:

The parameter for the acceleration in the expansion rate is termed DE...or Dark Energy, because as yet we just do not know specifically exactly the nature of it.

The theory most accepted, in fact overwhelmingly accepted, is the Big Bang. The observed expansion, along with the CMBR at a current 2.7K, and the abundance of H and He, lighter elements, and the large scale galactic structure are the four main pillars of the BB theory.

The addition of Inflation is seen as supporting other aspects such as the flatness and the isotropic nature of the observable universe.

thank you very much and for the first question i apologize. i meant accelerating expansion that occurs currently.