Blue shifted cosmic microwave background photons

[shomas]

I hope this is an appropriate forum for this question.

What kind sort of impact might intensely blue shifted cosmic microwave background (CMB) photons have on hawking radiation?

Could intensely blue shifted CMB photons drive a portion of newly created electrons and positrons into the even horizon before they annihilate giving off gama rays that wouldn't interact with income photons.

 

[Naty1]

What kind sort of impact might intensely blue shifted cosmic microwave background (CMB) photons have on hawking radiation?

short answer: I don't think any..

long answer:
Not sure just what you are getting at here. A distant observer, say on earth, would typically see CMBR as blue shifted approaching a distant black hole. This would be the opposite effect from observing red shifted photons were photons to emerge from a dense gravitational potential. But no black holes are emitting Hawking radiation, insofar as is known, because the universe is warmer than the black holes...so black holes are not currently evaporating.

If Hawking radiation were actually occurring, it would be because the black hole(s) were warmer than surrponding space (our universe)...and we'd observe some photons emerging. A rough analogy is to ask "how do photons from one star interact with those from another?"...in general electromagnetic radiation moves about with little interaction with other electromagnetic.

If you are referring to huge emissions of electromagnetic radiation from the vicintyof black holes, such as the center of aour galaxy, that frictional driven radiation from gas clouds outside the black hole rapidly accelerating in the vicinity of a massive black hole..it's not Hawking radiation which has never been observed.

Could intensely blue shifted CMB photons drive a portion of newly created electrons and positrons into the even horizon before they annihilate giving off gama rays that wouldn't interact with income photons

.

Again, I'm unsure what this means...but I'm not good on particle annihilation...
when a particle and it's antiparticle annihilate in quantum theory no energy is released...and Hawking radiation, when a particle (photon) is observed, it's photons (electromagnetic radiation) not electrons...like black body radiation...

Gamma rays are very high energy electromagnetic radiation, CMBR is low energy...but each is photons (bundles or quanta of electromagnetic radiation) just different frequency and different energy...via E =hf...

 

[shomas]

Not sure just what you are getting at here. A distant observer, say on earth, would typically see CMBR as blue shifted approaching a distant black hole. This would be the opposite effect from observing red shifted photons were photons to emerge from a dense gravitational potential. But no black holes are emitting Hawking radiation, insofar as is known, because the universe is warmer than the black holes...so black holes are not currently evaporating.

While it is true that normal (approximate a lunar mass or above) black holes take in more energy from the CMB then they emit, it does not mean they emit zero black body radiation. So yes they are not evaporating (loosing mass), if they net more energy taken in then they emit.

The reference frame I am looking at is from the perspective of newly created positrons and electrons outside a black hole's event horizon. Gravitational tidal forces rip virtual particle pairs apart, one half falling below the horizon the other remaining outside and popping into existence (e.g surviving long enough to be observed or interact) at the expense of the mass of the black hole. Positrons and electrons will annihilate leaving behind gama radiation that would be red shifted as it climbs out of the gravity well.

Again, I'm unsure what this means...but I'm not good on particle annihilation...
when a particle and it's antiparticle annihilate in quantum theory no energy is released...and Hawking radiation, when a particle (photon) is observed, it's photons (electromagnetic radiation) not electrons...like black body radiation...

While true for virtual particles, from nothing into nothing before it can be observed or interact, it is a different case when real electrons and positrons annihilate releasing huge amounts of energy by E=MC^2

Gamma rays are very high energy electromagnetic radiation

Coming from the conversion of matter to energy yes they have lots of energy, but when gama rays originate near an event horizon they would be intensely red shifted by the time they reach the reference frame of a stationary observer at a safe distance.

CMBR is low energy...but each is photons (bundles or quanta of electromagnetic radiation) just different frequency and different energy...via E =hf...

From yours and my perspective, CMB photons do have low energy. From a reference frame just above an event horizon, gravitationally blue shifted CMB photons will have high energy.

Smaller black holes have stronger tidal forces then larger ones ripping virtual pairs apart at a faster rate and inversely proportionate to its event horizons surface area. The amount of red shift of photons will vary by distance from the event horizon where the newly created particles annihilate.

Back to my question. Will incoming intensely blue shifted CMB photons interact with newly created positrons and electrons shortening their new life and reduce their chance to meet and annihilate before falling into the black hole.

 

[pervect]

I hope this is an appropriate forum for this question.

What kind sort of impact might intensely blue shifted cosmic microwave background (CMB) photons have on hawking radiation?

Could intensely blue shifted CMB photons drive a portion of newly created electrons and positrons into the even horizon before they annihilate giving off gama rays that wouldn't interact with income photons.

Counter-streaming of infalling and outgoing radiation definitely has an effect on black hole geometry, but the concerns are different than what you describe.

See for instance http://jila.colorado.edu/~ajsh/insidebh/realistic.html

The infinite blueshift at the inner horizon of the Reissner-Nordström geometry was first pointed out by Roger Penrose in 19681. Penrose suggested that the infinite blueshift would destabilize the Reissner-Nordström geometry.

The full nonlinear character of the instability at the inner horizon was eventually clarified in a seminal paper by Eric Poisson & Werner Israel in 19902.

The instability, which Poisson & Israel dubbed “mass inflation,” is caused by relativistic counter-streaming between ingoing (positive energy) and outgoing (negative energy) streams near the inner horizon3.

Or one of the author's more technical papers http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVP-50FGY1M-2&_user=10&_coverDate=10%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1495563120&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f914eef4d90d37dd8b57ed213cc27a4f&searchtype=a")

 

[shomas]

The infinite blueshift at the inner horizon of the Reissner-Nordström geometry was first pointed out by Roger Penrose in 19681. Penrose suggested that the infinite blueshift would destabilize the Reissner-Nordström geometry.

The full nonlinear character of the instability at the inner horizon was eventually clarified in a seminal paper by Eric Poisson & Werner Israel in 19902.

The instability, which Poisson & Israel dubbed “mass inflation,” is caused by relativistic counter-streaming between ingoing (positive energy) and outgoing (negative energy) streams near the inner horizon3.

I am not certain of this but I believe that a Reissner-Nordström (charged) black hole would polarize virtual particles driving away particles of the same charge, while attracting the opposite charge making them more likely to fall into the even horizon and cancel any net charge the black hole may have. If one were to try to negatively charge a black hole, it my be that the genesis of hawking's radiation would tend more towards electrons, while it absorbs positions from the polarized vacuum.

I believe that a charged black hole is not stable, and would tend to a neutral state.
This makes me wonder how a black hole absorbs an electron. Will the electron polarize the vacuum already stressed by gravitational tidal forces, causing a positron hawking's radiation to form and annihilate the electron just before the electron could cross the event horizon? Could the same happen for protons? the resulting photons could then pass the event horizon. if it is so, then one could forget passing the outer event horizon intact.

If it is the case that black holes can not sustain a charge, then inner event horizons mathematically created by charge don't exist in nature, although inner event horizons created from spin may still be possible.

 

[pervect]

Spinning black holes have the same issues with "mass inflation". The math is slightly easier with charged black holes, though, so you'll see papers about the charged case and remarks that the solution for the spinning case is belived to be similar quite frequently.