Navigation
  • Home
  • Recent
  • Most Active
  • Popular
  • Blog
  • Credits
  • RSS
    		•
      Interaction
  • Register
  • Statistics
    		•
      Help
  • Suggestions
  • Contact Us
  • How to Edit
  • Help
    		•



    [Edit]


    The particle horizon in physical cosmology is the maximum distance from which particles (of positive or zero mass) can have travelled to the observer in the age of the universe.

    It is different from the event horizon:

      The particle horizon is defined as the largest comoving distance from which light can have reached the observer — at the present moment. This is also known as conformal time.
      Conformal time can also be defined as dt/a(t), where a(t) is the scale factor of the FLRW metric. It is describing a cosmology expanding in scale (and does not have a horizon).
      The event horizon is defined as the largest comoving distance from which light can ever reach the observer — at any time in the future.

        Particle horizon
            Source
            See also

    top

    Source
      Lars Bergström and Ariel Goobar: Cosmology and Particle Physics, WILEY (1999), page 65. ISBN 0-471-97041-7

    top

    See also






     
    Search more:
     

       
    Source Privacy License Download Contact Us Atlas
    Scientus.org Dictionary (Yet Another Wiki) RC : 1.39
    This article is licensed under the GNU Free Documentation License [copyleft]. It uses material from the Wikipedia article "Particle horizon". link