Value for redshift change in acceleration

In summary, cosmologists estimate that the acceleration of the universe began approximately 5 billion years ago. This acceleration was caused by the dominant influence of dark energy, which eventually overtook the decelerating effects of dark matter and baryons. The density of dark matter decreases faster than dark energy in an expanding universe, leading to the dominance of dark energy when the universe doubles in size. This phenomenon is constant in the case of a cosmological constant.
  • #1
jc09
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If the universe was decelarating and then started to accelerate can we calculate when this happened, and if so how can we do this?
 
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  • #2
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).
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The above is from Wikipedia

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

What is redshift and how does it relate to acceleration?

Redshift is a phenomenon in which light from distant objects appears to be shifted towards longer wavelengths. It is caused by the expansion of the universe, which stretches the wavelength of light as it travels through space. Redshift is directly related to acceleration because the faster an object is moving away from us, the greater its redshift will be. This means that objects with higher redshifts are accelerating away from us at a faster rate.

How is the value for redshift change in acceleration calculated?

The value for redshift change in acceleration is calculated using the equation z = Δλ/λ, where z is the redshift, Δλ is the change in wavelength, and λ is the original wavelength. This equation applies to both light and other forms of electromagnetic radiation, such as radio waves.

What is the significance of studying value for redshift change in acceleration?

Studying the value for redshift change in acceleration can provide valuable insights into the expansion rate of the universe and the nature of dark energy. It can also help us understand the evolution of galaxies and the distribution of matter in the universe.

Can the value for redshift change in acceleration be used to measure distances?

Yes, the value for redshift change in acceleration can be used to measure distances to objects in the universe. This is because the amount of redshift is directly proportional to the distance an object is from us. By measuring the redshift of an object, scientists can calculate its distance from Earth.

Are there any limitations to using the value for redshift change in acceleration as a measurement tool?

Yes, there are limitations to using the value for redshift change in acceleration as a measurement tool. For instance, redshift can also be influenced by factors such as gravitational lensing and the Doppler effect, which can make it difficult to accurately measure distances. Additionally, the value for redshift change in acceleration is dependent on the assumption that the universe is expanding at a constant rate, which may not be entirely accurate.

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