Jul 9, 2023 03:15
Anyways looking for some feedback on my latest ramblings
Jul 9, 2023 03:15
Ok this did not take too long
Jul 9, 2023 03:15
Maldacena seems to confirm as much by looking at four dimensions and doing a different wrapping, getting (2.6.1) which bears a different form.
Jul 9, 2023 03:14
Ok it seems this is true as I had suggested way before looking at Maldecena.
Jul 9, 2023 03:12
Can someone comment on this?
Jul 9, 2023 03:12
It does seem though that the entropy is not going to be unique but would depend on the wrapping mechanism.
Jul 9, 2023 03:11
I think I can reproduce this independently now ( ok fine because I have seen how it is done now)
Jul 9, 2023 03:10
@MitchellPorter I think I cracked the code! (2.38) and (2.39) in Maldacena derive (22.138) in Zwiebach. This is done through the area law.
Jul 9, 2023 03:06
not as bad
Jul 9, 2023 03:06
Oh! now ramond - ramond kicks in
Jul 9, 2023 03:03
2.5.1. of Maldecena seems to show the mechanism for the construction of the extremal black holes in 5 dimensions. This might be a good starting point
Jul 9, 2023 02:39
.. it seems. Let me check
Jul 9, 2023 02:38
D branes must contort
Jul 9, 2023 02:32
Yes he does on page 5
Jul 9, 2023 02:31
Let me check if Maldacena says as much
Jul 9, 2023 02:31
charge becomes mass
Jul 9, 2023 02:31
Maybe let us start with Kerr-Newmann and derive the extremal conditions
Jul 9, 2023 02:29
Someone please construct this
Jul 9, 2023 02:29
It seems the first step is to construct an extremal black hole.
Jul 9, 2023 02:28
BTW , I need someone to check me as I ramble on
Jul 9, 2023 02:27
We are doing stuff in 5 dimensions basically it seems 5 curled
Jul 9, 2023 02:27
one is working in Type II B string theory at low energy it seems
Jul 9, 2023 02:27
Two things seem to be evident
Jul 9, 2023 02:26
Ok let me still do some talking and open reasoning along the way.
Jul 9, 2023 01:46
This might take a few days
Jul 9, 2023 00:52
@MitchellPorter thank you I am taking a look at it now
Jul 7, 2023 09:45
I have now edited the question and removed the mention of high school-level math. I also just asked the question directly about, as in what is a black hole microstate and how is counting done. Perhaps some good nice answers might come up
Jul 5, 2023 17:54
@Ghoster At any rate, what do you make of my ramblings thus far?
Jul 5, 2023 17:54
@Ghoster, I am now ok with $ln P(N;b,f) ~ 2 \pi \sqrt{N/6 (b + f/2)}$ but not (22.142) I feel like this is the final step
Jul 5, 2023 17:54
So I want to know a bit more about the formula: $ S = 2 \pi \sqrt{N Q_1 Q_5}$ .. . (22.138) Zwiebach. Also I want to guess that the charges could be different here based on how we do the wrapping of branes.
Jul 5, 2023 17:54
At any rate one can extend this Kalb- Ramond thing to Ramond -Ramond or some such thing for branes and then use some voodoo (dimensional ) to get an effective maxwell field. So one can get charges this way. ok
Jul 5, 2023 17:54
$\frac{1}{k^2} = \frac{ \partial H^{\mu \nu \rho}}{dx^{\rho}} = j^{\mu \nu}$ one can compute vector charges and so on later
Jul 5, 2023 17:54
So I have read this now. Let me try to organize my thoughts first if this is even possible. Ok. It turns out that the framework where this is easiest to do is supergravity at least according to the text. Something like some approximation of Type IIB. ok sure. The specific construction of the extremal black hole in 5d is not quite discussed but ok. The expression for the entropy has charges. So I scribbled some analogues of standard things with gauge fields -- and field strengths, then upgraded to the Kalb-Ramond fields which I have asked about before on this site.
Jul 5, 2023 17:54
It seems his name is Zwiebach. I get the spelling wrong every time too.
Jul 5, 2023 17:54
@Ghoster Oh! I had no idea Zweibach's text had this too. We used the first part of this text and other texts for our graduate string theory class. There is a second semester of the string course coming up in Spring I believe. Maybe we will also cover this then. Ok, I have just now opened that page in the text. I think I will aim at reading and doing the exercises in chapter 22 starting right this minute.
Jul 5, 2023 17:54
Ok we can get technical now.
Jul 5, 2023 17:54
ok so how are these things calculated without appeal to ads/cft?
Jul 5, 2023 17:54
Ok, so it would seem to me, continuing down this rabbit hole that one computes the total energy of the system, then computes the "combinations" that give the total energy in the stringy system. One needs a partition function to begin.
Jul 5, 2023 17:54
Basically, you inject a known amount of energy in the system, and then count.
Jul 5, 2023 17:54
@Ghoster Ok, let's just start by saying a black hole is a collection of strings that are excited and doing their thing. We can get more technical but for the purposes of understanding let's start soft. So sitting here in bed and drinking a coffee, I am thinking to myself you need a number for the number of strings to form said ball being called a black hole, then one looks at the combinations and arrangements of energy packets amongst the strings. Again, omitting technical details and all for now. Please check the concept and let me know if I'm getting warmer.
Jul 5, 2023 17:54
It might also be helpful to even learn what a quantum state of a black hole is
Jul 5, 2023 17:54
@Ghoster, I don't know. I always feel like there could be a high-school-level explanation for every concept, math and all included or at least something where the steps are shown/ worked out.
Jul 5, 2023 17:54
@SBrian Yes. I think this would be helpful too. The blackhole itself is different from the spacetime around the black hole.
 
Aug 5, 2022 09:12
starting chapter 3 now.
Aug 5, 2022 09:12
Reading chapter 2. Learning notation and definitions
Aug 5, 2022 09:12
Thank heavens for google. I am now looking up a lot of new math vocabulary while still just reading chapter 1.
Aug 5, 2022 09:12
I'll be reading the first chapter today.
Aug 5, 2022 09:12
ok, I just got the book. I have a copy with me now.
Aug 5, 2022 09:12
Yes, thank you. I will be ordering the book today. There's quite a bit i need to learn.