Integrating Friedmann Equation of Multi-component universe respect to a and t

In summary, The conversation discusses the trouble of finding the relationship between 'a' and 't' by integrating the Friedmann equation in a multi-component universe. The person is specifically looking for help with the matter-curvature only and matter-lambda only universes, and provides the two integrals for each. The conversation concludes with a suggestion to use substitution and a table of integrals to solve the problem.
  • #1
4everphysics
19
0
I am having a trouble finding relationship between 'a' and 't' by integrating friedmann equation in a multi-component universe.

It would be very helpful if you can help me with just
matter-curvature only universe and matter-lambda only universe.

The two integrals looks like following.

Matter-curvature only:

[tex]H_0 t = ∫_0^a \frac{da}{[Ω_0/a + (1-Ω_0)]^{1/2}} [/tex]

Matter-Lambda only:

[tex]H_0 t = ∫_0^a \frac{da}{[Ω_0/a + (1-Ω_0)a^2]^{1/2}} [/tex]

Thank you for your help.
 
Space news on Phys.org
  • #2
Try substituting x = 1/a and then use a table of integrals.
 
  • #3
with matter lambda the result is
a(t)=(ro_matter/ro_lambda)^(1/3)*[sinh[(6*Pi*ro_lambda*G)^(1/2)*t]^(2/3)
Where ro_x/ro_critical=omega_0x
 

Related to Integrating Friedmann Equation of Multi-component universe respect to a and t

1. What is the Friedmann Equation?

The Friedmann Equation is a mathematical equation used in cosmology to describe the expansion of the universe. It was developed by the Russian physicist Alexander Friedmann in the 1920s and is a key component of the Big Bang theory.

2. How does the Friedmann Equation relate to the expansion of the universe?

The Friedmann Equation is used to calculate the expansion rate of the universe based on the energy and matter content of the universe. It takes into account the densities of different types of matter and energy, such as radiation, dark matter, and dark energy, to determine the overall expansion rate.

3. What is meant by "multi-component universe" in the context of the Friedmann Equation?

A multi-component universe refers to a universe that is composed of multiple types of matter and energy. This includes normal matter, dark matter, and dark energy, which all have different densities and contribute to the overall expansion of the universe.

4. How does the Friedmann Equation change when considering the expansion of a multi-component universe over time?

The Friedmann Equation is integrated with respect to both time and scale factor (a) to account for the changing expansion rate of a multi-component universe. This allows for a more accurate calculation of the expansion rate over time, taking into account the changing densities of different types of matter and energy.

5. What are the practical applications of integrating the Friedmann Equation for a multi-component universe?

The integrated Friedmann Equation is used in cosmology to better understand the evolution of the universe and to make predictions about its future expansion. It also helps to validate the Big Bang theory and provides insights into the composition of the universe and the role of dark energy in its expansion.

Similar threads

Replies
6
Views
2K
Replies
21
Views
2K
Replies
27
Views
4K
Replies
3
Views
1K
  • Cosmology
Replies
12
Views
2K
Replies
40
Views
3K
  • Cosmology
Replies
7
Views
2K
Replies
6
Views
1K
  • Cosmology
Replies
1
Views
1K
Replies
3
Views
1K
Back
Top