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Is there a temperature that black holes cease to emit non-zero mass particles.
The fermions emitted, of course, will follow a Fermi-Dirac distribution instead of Planck.I think you can still pretty much get away with using Planck's law, just interpreting hf as the mass-energy of the particle. I'm sure the statistical counting of polarization states is wrong, and the stuff relating to identical particles is wrong if the particles being emitted are fermions, but basically I think the shape of the high-energy tail of Planck's law just follows from the partition function.
An important difference between the black hole radiation as computed by Hawking and thermal radiation emitted from a black body is that the latter is statistical in nature, and only its average satisfies what is known as Planck's law of black body radiation, while the former fits the data better.
Is there a temperature that black holes cease to emit non-zero mass particles.
Quoting Birrell & Davies,It would be interesting to estimate how much of an astrophysical black hole's mass is destined to be emitted as neutrinos, etc.
If it can, doesn't this thwart Penrose CCC which was just discussed in another thread. There, no one questioned the emission of radiation only from black holes at the end of this eon...no massive particles were claimed to be emitted.
Yes indeed! The book points out that the diameter of such a black hole would be about a fermi.A black hole hotter than 109K would seem really unusual...really small...
Is this saying as BH get smaller, hotter, they emit larger proportions of massive particles??
So this is why the radiation from the hole is almost entirely massless until its last dying gasp.
First of all I had not been aware if that is in fact accurate; if it is accurate, it was entirely missed in the Penrose CCC discussion by several forum experts and apparently by Penrose himself.
I listened to the entire Penrose lecture about his CCC theory at Perimeter online a few days ago and if he said anything about partile emission from BH at the end of the universe, when he appears to claim all is radiation, I'd be really surprised...
The real problem with CCC is that he needs nonstandard particle physics to get all his massive particles to decay into photons.
.) As we approach the Big Bang,
moving back in time, we expect to find temperatures that
are increasingly great. And the greater the temperature,
the more irrelevant the rest masses of the particles
involved will become, so these particles are effectively
massless near the Big Bang.
I don't see the relevance of the Higgs boson.
I assume no Higgs, no 'matter'...thats a potentially slick way to eliminate mass...
and Penrose mentions the Higgs field reappearing in the early universe...he did not make clear when it 'disappeared' in his view...
I'm wondering if the Higgs field can exist in a conformally geometric universe...if not, no mass!