Neutrino flux at event horizon

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  • Thread starter corbymite
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  • #1
corbymite

Main Question or Discussion Point

Hi, Assuming an average Neutrino mass of 2.0 Electron volts how much mass will a black hole with an event horizon the size of the one at the center of our galaxy accrete in a year? I've seen estimates of how many Neutrinos pass through our bodies each second and it seems like the mas would really add up over the surface area of a black hole.

Cheers,
Corby
 

Answers and Replies

  • #2
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What do you get if you take this neutrino flux and multiply it with the black hole cross section? Compare it to the mass of the black hole.

2 eV is above the limits from cosmology, by the way. Stellar neutrinos will have most of their energy as kinetic energy and the neutrino mass is irrelevant for them.
 
  • #3
corbymite
OK use .2 Electron volts, a radius of 13 million kilometers, and an area of 2.12E+17 square Centimeters. If the Neutrino flux is say 1E+11 per square Centimeter then the total Neutrino flux would be 2.12E+28 per second or 6.68E+35 per year. Looks like this only would increase the black holes mass by 238 grams! Of course my values could be way off?
 
  • #4
34,484
10,613
The neutrino flux is smaller if you are not near a star, but the neutrino energies are higher. Anyway, the mass is completely negligible, even 20 orders of magnitude more wouldn't have a notable effect.
 

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