Undergrad 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 'Revisiting the Light Clock'

A good one to everyone. My previous post on this subject here on the forum was a fiasco. I’d like to apologize to everyone who did their best to comment and got ignored by me. In defence, I could tell you I had really little time to spend on discussion, and just overlooked the explanations that seemed irrelevant (why they seemed irrelevant, I will tell you at the end of this). Before we get to the point, I will kindly ask you to comment having considered this text carefully, because...
View full post »

Similar threads

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