Accurate Measurement of Cosmological Constant Value

In summary, the conversation is about asking for a recommendation for a paper that accurately provides the value of the cosmological constant. The most commonly used value is the density parameter (\Omega_\Lambda) with a latest value of 0.69, related to the cosmological constant through an equation. The Planck 2015 publications provide values for both \Omega_\Lambda and H_0 in paper XIII: Cosmological Parameters, table four. Additionally, a reference is provided with a predicted value of 1.388 × 10−123 in Planck units and a measured value of (1.48 ± 0.16) × 10−123.
  • #1
Einstein's Cat
182
2
Could anyone please recommend a paper that accurately gives the value of the cosmological constant? Or else may you reply with values of the cosmological constant that you would you use in your research? Any help would be very much appreciated.
 
Space news on Phys.org
  • #2
The most common value given is the density parameter ([itex]\Omega_\Lambda[/itex]) equivalent of the cosmological constant, with a latest value (Planck 2015) of about 0.69. This is related to the value of the cosmological constant by
$$\Lambda = \frac{3H_0^2}{c^2} \Omega_\Lambda$$
In this equation you have to convert H0 to per second (s-1), if you want to use SI units for c.
 
  • #3
The Planck 2015 publications mentioned by Jorrie can be found here:
http://www.cosmos.esa.int/web/planck/publications
You'll find values for ##\Omega_{\Lambda}## and ##H_0## in paper XIII: Cosmological Parameters, table four.
 
  • #4
Einstein's Cat said:
Could anyone please recommend a paper that accurately gives the value of the cosmological constant?
The predicted value of the density of the cosmological constant in Planck units is = 1.388 × 10−123
the measured value quoted in the reference below is (1.48 ± 0.16) × 10−123 .
REFERENCE:
http://arxiv.org/pdf/astro-ph/0703774v1.pdf
 

1. What is the cosmological constant value?

The cosmological constant value is a parameter in Einstein's theory of general relativity that represents the energy density of the vacuum of space. It is denoted by the Greek letter lambda (Λ) and is often referred to as the "dark energy" of the universe.

2. How is the value of the cosmological constant determined?

The value of the cosmological constant is determined through various observational and theoretical methods. It can be derived from the curvature of spacetime, the expansion rate of the universe, and the density of matter and radiation in the universe. Currently, the most widely accepted value for the cosmological constant is about 10^-122 in Planck units.

3. What is the significance of the cosmological constant value?

The cosmological constant value has significant implications for our understanding of the universe. It is responsible for the observed accelerated expansion of the universe and plays a crucial role in the formation and evolution of large-scale structures such as galaxies and galaxy clusters.

4. Has the value of the cosmological constant changed over time?

According to current theories, the value of the cosmological constant has remained constant throughout the history of the universe. However, some proposed theories suggest that it may have varied in the early stages of the universe's evolution. More research and observations are needed to determine if this is the case.

5. What are the implications of a changing cosmological constant value?

If the value of the cosmological constant is found to vary over time, it would have significant implications for our understanding of the universe's evolution and the fundamental laws of physics. It could potentially lead to a better understanding of the nature of dark energy and the dynamics of the universe's expansion.

Similar threads

Replies
2
Views
886
Replies
19
Views
2K
Replies
26
Views
2K
Replies
26
Views
2K
Replies
6
Views
2K
Replies
8
Views
2K
Replies
9
Views
1K
  • Cosmology
Replies
13
Views
2K
Replies
4
Views
993
Back
Top