Value for redshift change in acceleration

  • Thread starter jc09
  • Start date
  • #1
45
0

Main Question or Discussion Point

If the universe was decelarating and then started to accelerate can we calculate when this happened, and if so how can we do this?
 

Answers and Replies

  • #2
mathman
Science Advisor
7,798
430
Cosmologists estimate that the acceleration began roughly 5 billion years ago. Before that, it is thought that the expansion was decelerating, due to the attractive influence of dark matter and baryons. The density of dark matter in an expanding universe decreases more quickly than dark energy, and eventually the dark energy dominates. Specifically, when the volume of the universe doubles, the density of dark matter is halved but the density of dark energy is nearly unchanged (it is exactly constant in the case of a cosmological constant).
-----------------------------------------------------------------------------
The above is from Wikipedia

http://en.wikipedia.org/wiki/Dark_energy
 

Related Threads on Value for redshift change in acceleration

Replies
5
Views
761
Replies
4
Views
962
Replies
16
Views
15K
  • Last Post
3
Replies
52
Views
8K
  • Last Post
Replies
10
Views
2K
  • Last Post
Replies
2
Views
12K
Replies
1
Views
2K
Top