Particle horizon in Lemaître model

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SUMMARY

The particle horizon in the Lemaître model can be calculated using the time-dependent scale factor function derived from the Friedmann-Lemaître-Robertson-Walker (FLRW) metric. This integral provides a boundary between observable and unobservable parts of the universe. Current calculations indicate that the particle horizon is approximately 46 billion light years, with the furthest known object having a redshift factor of z=8.2, corresponding to a proper distance of about 30 billion light years. This information is crucial for understanding the universe's expansion and observable limits.

PREREQUISITES
  • Understanding of the Friedmann-Lemaître-Robertson-Walker (FLRW) metric
  • Knowledge of cosmological redshift and its implications
  • Familiarity with integral calculus in the context of cosmology
  • Basic concepts of the observable universe and cosmic expansion
NEXT STEPS
  • Research the Friedmann equations and their applications in cosmology
  • Study the implications of redshift in observational astronomy
  • Learn about the calculation of the scale factor in cosmological models
  • Explore the concept of cosmic inflation and its effects on the universe's expansion
USEFUL FOR

Astronomers, cosmologists, physics students, and anyone interested in the mathematical foundations of the universe's observable limits.

EhsanZ
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What is the exact calculation of Particle horizon in Lemaître model? Does it exist? Is it finite or infinite?
Can anyone calculate that integral?
Thanks
 
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EhsanZ said:
What is the exact calculation of Particle horizon in Lemaître model? Does it exist? Is it finite or infinite?
Can anyone calculate that integral?
Thanks

The particle horizon marks the boundary between observable and un-observable parts of the universe, and yes, this integral can be calculated using the time-dependent scale factor function taken from the FLRW metric, as well as observational parameters. So far as I could find ( these things change pretty regularly ) the furthest know object to date has a redshift factor of z=8.2 which would be equivalent to a proper distance ( remember, this is not the same as light-travel distance due to the dynamic expansion of spacetime ) of about 30 billion light years. Reference :

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

If you do the maths from the integral you arrive at a figure of about 46 billion light years.
 
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