Particle horizon rewritten

In summary, the Particle Horizon is a concept in cosmology that represents the maximum distance from which light or particles can have reached us since the beginning of the universe. It is rewritten by taking into account the expansion of the universe and the effects of dark energy, resulting in a larger horizon distance. This concept is important as it provides information about the size and age of the observable universe, as well as the expansion of the universe and the nature of dark energy. The Particle Horizon is calculated using the Hubble parameter and the age of the universe, and can change over time due to the continuing expansion of the universe and changes in the amount of dark energy.
  • #1
Lapidus
344
11
Here http://www.damtp.cam.ac.uk/user/db275/Cosmology/Lectures.pdf, I find on page 31 in (2.1.5)
distance.PNG


I assume that it is childish calculus that connects both sides of this equation. But still, can someone help me why the integral can be rewritten like that?

thanks!
 
Space news on Phys.org
  • #2
It is a standard change of variables.

##\int f(a(t)) dt = \int f(a) (dt/da) da##
 
  • Like
Likes Lapidus

1. What is the Particle Horizon?

The Particle Horizon is a concept in cosmology that refers to the maximum distance from which light or particles can have reached us since the beginning of the universe.

2. How is the Particle Horizon rewritten?

The Particle Horizon is rewritten by taking into account the expansion of the universe and the effects of dark energy. This results in a larger horizon distance compared to the traditional calculation.

3. Why is the Particle Horizon important?

The Particle Horizon provides important information about the size and age of the observable universe. It also helps us understand the expansion of the universe and the nature of dark energy.

4. How is the Particle Horizon calculated?

The Particle Horizon is calculated using the Hubble parameter, which describes the rate of expansion of the universe, and the age of the universe. It is also affected by the amount of dark energy present in the universe.

5. Can the Particle Horizon change over time?

Yes, the Particle Horizon can change over time as the universe continues to expand and the amount of dark energy changes. This means that the maximum distance from which light or particles can reach us will also change.

Similar threads

Replies
1
Views
3K
Replies
1
Views
807
  • Cosmology
Replies
12
Views
3K
  • Cosmology
Replies
4
Views
1K
Replies
4
Views
1K
Replies
1
Views
984
Replies
7
Views
2K
Replies
2
Views
1K
  • Cosmology
Replies
11
Views
1K
Back
Top