Kerr & Nordström Black Hole Evaporation: Q&A

In summary, the Kerr parameter is an expression of angular momentum, speed of light, gravitational constant, and mass of a black hole. It ranges between zero and unity for any black hole, with a Schwarzschild hole having a value of zero. When a Kerr black hole evaporates due to Hawking radiation, the value of the Kerr parameter remains constant at its initial value, approaches zero, approaches unity, or approaches a value between zero and unity. In the case of Nordström black holes, the presence of matter causes a strong attraction for charged plasma, but in a perfect vacuum, there would be a leak current out of the black hole. Quantum mechanics suggests that in strong electric fields, there is a tail of tunnelling.
  • #1
snorkack
2,190
477
When a Kerr black hole evaporates, what will the Kerr parameter do?
Stay constant at initial value?
Approach zero?
Approach unity?
Approach a target value somewhere between zero and unity?

Also, Nordström black holes in practice (with matter around) would have a strong tendency to attract charged plasma. But in perfect vacuum? How strong would the leak current out of a Nordström black hole be? Quantum mechanics suggests a tail of tunnelling in strong electric fields. At which charge would a Nordström black hole be evaporating at constant q/m, if the dependence of q on m is that simple? And does the mathematics of Nordström black hole expressly depend on electron rest mass?
 
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  • #2
snorkack said:
the Kerr parameter
What do you mean by the Kerr parameter?
 
  • #3
PeterDonis said:
What do you mean by the Kerr parameter?
The expression
Jc/GM2
where J is angular momentum, c speed of light, G gravitational constant and M the mass of the hole.
It is bound to be between zero (it is Schwarzschild hole) and unity for any black hole.
How does it evolve on Hawking radiation?
 
  • #4
If you search "Hawking evaporation Kerr BH" you find a good number of reputably published papers discussing this. At the moment, I don't have time to quick read them to try to choose the most informative.
 

1. What is the Kerr & Nordström Black Hole Evaporation theory?

The Kerr & Nordström Black Hole Evaporation theory is a hypothesis proposed by Roy Kerr and Gunnar Nordström in the 1960s, which suggests that black holes can gradually lose mass and energy over time through a process known as Hawking radiation.

2. How does Hawking radiation contribute to the evaporation of black holes?

Hawking radiation is a type of radiation that is predicted to be emitted by black holes due to quantum effects near the event horizon. This radiation carries away energy from the black hole, causing it to gradually lose mass and eventually evaporate.

3. Can black holes completely evaporate?

According to the Kerr & Nordström Black Hole Evaporation theory, black holes can evaporate completely if they are not constantly gaining mass. However, this process is extremely slow and it would take an incredibly long time for a black hole to completely evaporate.

4. How does the spin of a black hole affect its evaporation?

The spin, or angular momentum, of a black hole can affect its evaporation rate. A rapidly spinning black hole may have a higher evaporation rate compared to a non-spinning black hole due to the presence of ergosphere, which is an area outside the event horizon where energy can be extracted from the black hole's rotation.

5. Is there any evidence for the Kerr & Nordström Black Hole Evaporation theory?

Currently, there is no direct evidence for the Kerr & Nordström Black Hole Evaporation theory. However, the theory is based on well-established principles of physics, such as general relativity and quantum mechanics. Further research and observations of black holes may provide evidence for this theory in the future.

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