How to calculate the age of the universe with redshift

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SUMMARY

The age of the universe can be calculated using redshift values by determining the lookback time (t_L). For a redshift of 0.6, the formula t_L = t_H * (2/3) * (1 - (1+z)^(-3/2)) is applied, where t_H is the Hubble time, approximately 13.8 billion years. This results in a lookback time of approximately 0.337 times the Hubble time, which translates to about 4.66 billion years. The scale factor, R(t) = 1/(1+z), is essential for these calculations, with R(t_0) set to 1 for the present time.

PREREQUISITES
  • Understanding of redshift and its implications in cosmology
  • Familiarity with the Hubble constant (H_0) and Hubble time (t_H)
  • Basic knowledge of cosmological equations and scale factors
  • Access to a cosmology textbook for reference on formulas
NEXT STEPS
  • Study the derivation of the lookback time formula in cosmology
  • Learn about the implications of different redshift values on cosmic age
  • Explore the relationship between scale factors and redshift in a flat universe
  • Investigate the significance of the Hubble constant in cosmic measurements
USEFUL FOR

Astronomers, astrophysicists, and students studying cosmology who seek to understand the relationship between redshift and the age of the universe.

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Hi i am confused as to how to calculate the age of the universe with redshift
say for example

The age of the universe now is 13.4 billion years old (and a critical universe).
How do i find the age of the universe if it was a redshift at say 0.6??

Do i have to find the scale factor first?
I am not very sure, please help!
 
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someone help me with it please
 
The scale factor is related to the red shift.

R(t) = 1/(1+z) ; where R(t) is the scale factor at time t. R(t_0) = 1, t-0 is today.

What we want is the "lookback time" (t_L)

For a flat Universe, this is:

t_L = t_H * (2/3) * (1 - (1+z)^(-3/2))

t_H is the Hubble time ( 1 /H_0 ); approx 13.8 Gyr.
H_0 is the Hubble constant.

t_L = 0.337 t_H

I don't know what values you have in your book and so on, but this one way to solve it, there is probably more. The way to deduce the forumulas is pretty straightforward, it should be stated in our course book in cosmolgy.
 

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