I Kerr & Nordström Black Hole Evaporation: Q&A

Click For Summary
The discussion centers on the behavior of the Kerr parameter during the evaporation of Kerr black holes, questioning whether it remains constant, approaches zero, unity, or a value in between. It also explores the characteristics of Nordström black holes, particularly their interaction with charged plasma and the implications of quantum tunneling in vacuum conditions. The conversation highlights the relationship between the Kerr parameter, defined as Jc/GM², and its evolution during Hawking radiation. Participants reference existing literature on Hawking evaporation in Kerr black holes for further insights. The complexities of these black hole models and their mathematical dependencies are emphasized as critical areas for future research.
snorkack
Messages
2,388
Reaction score
536
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?
 
Physics news on Phys.org
snorkack said:
the Kerr parameter
What do you mean by the Kerr parameter?
 
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?
 
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.
 

Thread 'Jackson: justification of the Poynting vector by GR'

The Poynting vector is a definition, that is supposed to represent the energy flow at each point. Unfortunately, the only observable effect caused by the Poynting vector is through the energy variation in a volume subject to an energy flux through its surface, that is, the Poynting theorem. As a curl could be added to the Poynting vector without changing the Poynting theorem, it can not be decided by EM only that this should be the actual flow of energy at each point. Feynman, commenting...
View full post »

Similar threads

I Questions about Hawking radiation and extremal black holes...?
Replies
4
Views
1K
I Falling through the event horizon of an evaporating black hole
2
Replies
51
Views
4K
I Kerr disputes singularities in Kerr Black Holes
Replies
7
Views
3K
I I don't see how a black hole's event horizon can be crossed
2
Replies
73
Views
903
I Merging black holes: gravitational waves and information
Replies
12
Views
2K
A Exact meaning of the mass M in the Kerr metric event horizon formula?
Replies
4
Views
1K
B Paradox about black hole evaporation
Replies
35
Views
4K
I How Does Hawking Radiation Lead to Black Hole Evaporation?
Replies
8
Views
2K
I Rotating Black Holes: A Century of Discovery & Beyond
Replies
7
Views
1K
I What are the effects on a stationary observer for Kerr metric?
Replies
43
Views
4K