Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,047 questions , 2,200 unanswered
5,345 answers , 22,709 comments
1,470 users with positive rep
816 active unimported users
More ...

  What really are exotic supersymmetric black holes?

+ 7 like - 0 dislike
1865 views

I have just read (in the black holes chapter 14 on p244 of this book Ref.1) that in string theory, when one adds an (electric?) charge $Q$ to a static black hole, one can arrive at an exotic supersymmetric black hole. This sentence is not explained further and there are several (I think related enough) things I dont understand about it, which can be summerized under the question what really is an exotic suppersymmetric black hole?

First, how exactly does the addition of a charge (if it is not outright a supercharge) lead to supersymmetry?

Second, what is meant by an exotic black hole, conversely to for example an extremal black hole that has just the maximum charge allowed given its mass?

Third, what does it mean for a black hole to be supersymmetric anyway?

References:

  1. D. McMohan, String Theory Demystified, McGraw-Hill, 2009
asked May 25, 2013 in Theoretical Physics by Dilaton (6,240 points) [ revision history ]
Can you provide a link to or quote the source? Context may help.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Brandon Enright
@BrandonEnright ok, I have even found a PDF of the book and put it into the question.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Dilaton
@Dilaton: It is best to supply title, author, etc, of link, so we can reconstruct the link in case of future link rot.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Qmechanic
@Dilaton I've heard that extremal black holes are solitonic solutions of supergravity, preserving some degree supersymmetry. I myself do not understand what it means, but I know it is important.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Prathyush
Dear Dilaton, the adjective "exotic" in front of a black hole isn't a technical term with a particular meaning. It just means that, subjectively to the author, the black hole is unusual for the author of the sentence, usually because she is used to Schwarzschild-like neutral black holes from the undergrad courses. At any rate, there exists a maximum Q given a fixed mass for which the black hole is "extremal" and such black holes often preserve a part of the supersymmetry (if it was there to start with), have infinite throats near the event horizon, and other qualitative differences from neutr.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Luboš Motl
Thanks Lumo, darn I really thought that exotic is a technical term. David McMohan bazinga me :-D. Maybe I should complain the next time he appears on TRF. What an extremal black hole is I have understood now I think, but the notion of a black hole to be (or to preserve) supersymmetric still confuses me, even though I know a but what it means for a Lagrangian to be supersymmetric etc ... I mean how should the presence of a black hole break supersymmetry if it is not such an extremal one? Hoping my confusion provokes an answer I can visibly appreciate by upvote :-P

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Dilaton
There are exotic spheres, exotic differential structures in maths etc. but these things aren't really too exotic. ;-)

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Luboš Motl
@LubošMotl yep, David McMohan that rascal (!) really bazingaed me about this :-P. Do you have an answer to the rest ;-)?

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Dilaton
The link is dead already.....

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Dimensio1n0
@dimension10 ah I see, that was a link to a PDF. I now added in a more stable link to amazone.

This post imported from StackExchange Physics at 2014-03-09 16:18 (UCT), posted by SE-user Dilaton

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar\varnothing$sicsOverflow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
Please complete the anti-spam verification




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...