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Properties of nuetrinos in space

  1. Mar 28, 2012 #1


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    Just a couple of numbers I'm having trouble finding.

    Does anyone know what a typical energy for a nuetrino ejected from the sun is?

    Any number on a guess-timate of what the density of nuetrinos is in deep space?

    Also, same two questions for electron nuetrinos and Tau nuetrinos.

    A 1 Gev Nuetrino, would the gamma for this nuetrino be 4.5(10^8)?
  2. jcsd
  3. Mar 28, 2012 #2


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    Quick reply on the last question. The gamma would be strongly dependent on neutrino rest mass, which is unknown. The gamma would certainly be very large and of the general order you propose.
  4. Mar 28, 2012 #3
    Hi! For what concerns the first question, see


    figure 2.

    For what concerns the secon question


    "The theory estimated also the neutrino density in the universe: about 110 per cm3, for each neutrino family, that means 330 neutrinos per cm3 as a whole"

    For what concerns the question on the gamma, one should know the masses of the neutrinos; it is quite accepted that they are massive, but, as far as I know, there is a lot of uncertainty about their value; so you cannot compute the gamma; notice that if you know the mass m then you can simply solve computing gamma=E/m.

    Best, Francesco

    PS: Sorry PAllen; I have sent the post short after you..
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