Wikipedia:Featured article candidates/AdS/CFT correspondence/archive1

AdS/CFT correspondence

Featured article candidates/AdS/CFT correspondence/archive1

Nominator(s): Polytope24 (talk) 23:25, 5 October 2013 (UTC)[reply]

I am nominating this for featured article because... I believe it meets the FA criteria. I've been working on this article for months now, and it was recently promoted to good article status. Since then, I've significantly expanded the article to make it more comprehensive. Polytope24 (talk) 23:25, 5 October 2013 (UTC)[reply]

Comments by Chris857: There are two images here, File:Escher Circle Limit III.jpg and File:AdS3.png. Circle Limit is non-free, and AdS3 is a derivative work of it. Is there any necessity to use Circle Limit when File:Uniform tiling 433-t0.png is the same pattern, but freely licensed? File:AdS3.png should be modified to use the free pattern. Chris857 (talk) 18:31, 6 October 2013 (UTC)[reply]

Are there any other thoughts about this? I explained my rationale for using the Escher image over at File:Escher Circle Limit III.jpg. I can change the images if the community deems it necessary, but the Escher image is prettier, and I think I'm justified in using it… Polytope24 (talk) 21:23, 6 October 2013 (UTC)[reply]

Is the suggested replacement sufficient for the same encyclopedic purpose? I.e. does it convey the same information needed to understand the article or section? If yes, the non-free image and its derivative should be replaced. Being more famous or prettier is no valid rationale to prefer the non-free version. (Off-topic for this FA: Usage in Möbius transformation is also questionable. Other usages in the remaining articles appear to have stronger rationales, as the woodcut is either the focus of those articles or is discussed in more detail.) GermanJoe (talk) 09:12, 8 October 2013 (UTC)[reply]

Okay, I changed the images. Polytope24 (talk) 16:53, 8 October 2013 (UTC)[reply]

Comment: I am concerned about this article. The topic of the article is very complex physics, and the subject is accessible to a very small number of people. Because of this, there are very few Wikipedia editors capable of usefully editing the content (as opposed to the formatting) of this article, and of critiquing the article as a whole. Indeed, almost all recent edits (from mid-August) have been by Polytope24, and it seems to me that the GA review was carried out with input only from one other editor, SPat. I would feel more comfortable about granting this article "featured" status if we were able to find a few more appropriately-qualified editors to review it. None of this is meant to disparage the article as it currently stands, or Polytope24's hard work; I'd simply like to confirm that adequate reviews have been performed. RomanSpa (talk) 22:36, 9 October 2013 (UTC)[reply]

Thanks for your comments. It's true that the subject of this article is very technical, but I've tried to write the article in such a way that even non-experts can understand and verify its content. If you look at the references, you'll notice that much of the article is based on a popular article by Juan Maldacena in Scientific American. I would love to have more non-experts weigh in on this article and tell me if they find it accessible.

That said, I understand that it's difficult for a non-expert to support or oppose this nomination. If you like, I can look for people to review the article. I could probably find someone over at Wikipedia:WikiProject Physics. Polytope24 (talk) 23:19, 9 October 2013 (UTC)[reply]

I think that would be an excellent course of action. Thank you. RomanSpa (talk) 12:28, 10 October 2013 (UTC)[reply]

Comment I came here from a request at WT:Physics as a physicist, but don't claim to know anything about FA criteria or judging process. I'll stick to content. I've worked through the article up to but not including the Applications to quantum field theory section.

Overall I'd say that given the difficulty of the material, the article is well written and neutral. AdS/CFT is somewhat controversial in some parts of the physics community and the article is correct to have a criticism section (Disclaimer: I have a connection to P.W. Anderson, who is one of those critics). I don't see any undue biases in the presentation of subtopics. One subtopic I don't see mentioned is the correspondence with a particular tpye of viscous fluid dynamics, e.g., [1] and [2]. But perhaps this is discussed in the Sachdev article; I don't have access to that at the moment.

Here are some particular things that could be improved in the article. I'm being intentionally picky here. Compared to most physics article, this one is well referenced.

conformal field theory is a scale invariant quantum field theory -- Not all scale invariant QFTs are automatically conformally invariant.
The surface of this cylinder is called the conformal boundary of three-dimensional anti-de Sitter space. -- This needs a reference; the SciAm article referenced in the same para does not mention conformal boundary.
It may also be good to explain what is meant by a conformal boundary, since it is such a core concept in the correspondence. A naive reader might say 'You just told me that AdS has a metric, a definite measure of distance. How is the boundary of that space now magically scale invariant?'
Here the gravitational theory has four noncompact dimensions, so this version of the correspondence provides a somewhat more realistic description of gravity. -- Probably needs a ref--who says this theory is a more realistic description of gravity? It is a reasonable statement, but we cannot draw our own conclusions here.

Hope this is helpful and apologies for anything irrelevant to FAC. --Mark viking (talk) 22:14, 11 October 2013 (UTC)[reply]

Thank you - this looks very good. I hope that we can find someone to perform a similar review on the second half of the article. RomanSpa (talk) 23:01, 11 October 2013 (UTC)[reply]

Thank you Mark viking for this helpful review. I've made the following changes in response to your comments:

1. I've changed every instance of the term "conformal boundary" to "boundary" as in the SciAm article by Maldacena. The precise definition of conformal boundary is rather technical, and it seems unnecessary to include it in this article, which is supposed to provide a nontechnical overview. Besides, the article already makes it clear that the boundary we're talking about is infinitely far from any point in the interior.

2. I made some changes to the section on quantum field theory to emphasize that a conformal field theory is a special type of highly symmetric theory, not just a scale invariant one.

3. I added a more specific citation for the claim that the AdS4/CFT3 correspondence provides a more realistic description of gravity.

4. I had originally decided not to discuss applications to fluid dynamics in this article because it's not clear to me that there are any really serious applications to fluid dynamics. Since you noticed this omission, I have added a sentence to the end of the history section noting that this is a topic of current research.

Please let me know if I've failed to address any of your concerns. Thanks again. Polytope24 (talk) 01:20, 12 October 2013 (UTC)[reply]

Thanks for addressing these points. I agree with your decision to drop the 'conformal' from conformal boundary for the sake accessibility. All your other changes look good. I agree that the fluid dynamics connection warrants no more than a sentence. You've addressed all my points. --Mark viking (talk) 05:04, 12 October 2013 (UTC)[reply]

Comment on the second half of the article (see the comments on the first half above). I also found this half to be well written and well referenced. As above, here are some picky criticisms:

fluid is viewed as a field theoretic analog of a black hole. -- as written, I cannot tell what this means. What is the field theoretic analog of a black hole? I can make some guess, but best to provide a little more descritpion here.
In 1999, after taking a job at Columbia University, nuclear physicist Đàm Thanh Sơn paid a visit to Andrei Starinets, a friend from Sơn's undergraduate days who happened to be doing a Ph.D. in string theory at New York University. -- This level of detail on undergraduate friendships is a nice story, but is a trivial detail in a broad summary of the whole topic. Perhaps best to reduce to excise it.
Such a duality is interesting from the point of view of cosmology since many cosmologists believe that the very early universe was close to being de Sitter space. -- citation needed for many cosmologists believing this.
In the Black hole information paradox section you alluded to the Bekenstein bound for black hole information and in the later Black holes and holography section, you mentioned the holographic principle Both these concepts are closely related, as mentioned in both articles. There should be some mention of the connection of these in this article. Although Black hole information paradox and Black holes and holography are split into two sections, they are fairly closely related.

I'm not qualified to judge whether this meets FAC, but I must say, well done! --Mark viking (talk) 04:58, 12 October 2013 (UTC)[reply]

Thanks for these comments. Here's a summary of what I did:

1. I clarified the sentence on "field theoretic analog of a black hole".

2. For now, I'm leaving the story about Son and Starinets as it is. During the GA review of this article, I was encouraged to add lots of details and trivia to the history section since this is the section that lay readers will focus on. The thinking was that such readers will be most interested in historical details, anecdotes, and personal relationships of the scientists involved in AdS/CFT. I would like to hear what other reviewers think about this decision. If others agree that there's too much trivial information, then I'll go ahead and change it.

3. I added a citation on the early universe being close to de Sitter space.

4. It seems there was some confusion about my reference to Jacob Bekenstein in the section "Black hole information paradox". It was not my intention to say anything about the Bekenstein bound. In fact, the reference in that section was unnecessary and works much better in the history section, so I moved it. I hope this helps to streamline the article a bit.

Thanks again, and please let me know if there are any other issues. Polytope24 (talk) 06:22, 12 October 2013 (UTC)[reply]

Thanks for addressing my points. I wasn't aware of the GA discussion about the history section. If adding details and trivia is what is wanted there, that's OK by me; I have a tendency to just concentrate on the physics. I agree that the Bekenstein info makes more sense in the history section. You have addressed all my points.

I cropped the Susskind photo to emphasize the man, rather than his table, and pointed the article to the cropped version. Feel free to revert if you don't think it is an improvement. --Mark viking (talk) 10:26, 12 October 2013 (UTC)[reply]

No, that looks great. Thank you. Polytope24 (talk) 15:22, 12 October 2013 (UTC)[reply]

Comment: I like how this article manages to find a nice balance between being technical and accessible. While some may ding you on accessibility, on my read-through, even with no understanding of the math behind string theory and its extensions, I was still able to understand what it meant, but not at the expense of technical details. Nonetheless, there are a few things that I think could use some work:

I think it would be nice to have some more consistency in using "we" versus "one" when describing things.
How does this theory solve the black hole information paradox? I was not quite clear on this while reading the article?
"Some condensed matter theorists hope that the AdS/CFT correspondence will make it possible to describe these systems in the language of string theory and learn more about their behavior.[48]" Any examples of who?
"During the transition, the atoms behave in an unusual way," in what way is their behavior unusual?
In the criticism section, refs need to go at the end of the quote, as well as where they are now.
I think the history section goes a little too in-depth about Hawking's black hole work.

Other than these, the article looks good to me, and I'd support after these issues are resolved. StringTheory11 (t • c) 17:22, 13 October 2013 (UTC)[reply]

Thanks for your comments. I'll make changes as soon as possible, hopefully later today. Polytope24 (talk) 18:25, 13 October 2013 (UTC)[reply]

Okay, I just finished making some changes. Rather than remove anything in response to your last comment, I actually added some language to explain why Hawking's work is very important in the history of AdS/CFT. In the previous version, I think maybe it wasn't clear why explained his work in depth.

Thanks for helping out with the review, and let me know if you have any further comments. Polytope24 (talk) 05:02, 14 October 2013 (UTC)[reply]

Support, content concerns addressed. StringTheory11 (t • c) 03:16, 22 October 2013 (UTC)[reply]

Comment At this point I've received some excellent feedback by several other editors, but I'm concerned that the FAC coordinators may close the nomination if there are no other reviews. I would appreciate any suggestions from editors who have more experience with the review process. (RomanSpa may have something to say about this.)

I would also like to make a couple of observations related to WP:FA Criteria:

In his review, Mark viking stated that the article was "well written", "neutral", and "well referenced".

The only comment about comprehensiveness was that the article should mention applications to fluid dynamics, and this point has now been addressed.

Chris857 and GermanJoe had some concerns about pictures which have now been addressed.

The article was recently reviewed by SPat and promoted to GA status. This means that it is well written, well referenced, neutral, stable, and illustrated by appropriate images.

Since there don't seem to be any concerns about adherence to WP:MOS, I'm inlined to say that this article meets all the criteria. I would support it myself, but I'm not sure if that's acceptable considering that I nominated the article. I would appreciate any advice people have. Polytope24 (talk) 19:44, 24 October 2013 (UTC)[reply]

Comment

I am coming here as a mathematician familiar with AdS/CFT (although not an expert on the physics) because of a request from the principal editor at WT:WPM. In my corner of the world, the AdS/CFT correspondence is typically associated with the names of Charles Fefferman (of Princeton University) and Robin Graham (of the University of Washington) owing to a paper on the subject that they published in a special issue of the journal Asterisque some time in the 1980s (a more detailed and quite recent paper by these authors is available on the arxiv [3]). A reference to this work is conspicuously missing from the article. Sławomir Biały (talk) 00:11, 27 October 2013 (UTC)[reply]

Thanks for the suggestion. The work that you mention is the subject of one of the links in the "See also" section. I also went ahead and added a footnote and reference. Polytope24 (talk) 01:05, 27 October 2013 (UTC)[reply]

Comment

I was solicited by the principal editor. I am a theoretical physicist and I am aware of Maldacena's conjecture mostly from works in AdS/QCD. As far as I can tell, there has been some effort by Cumrun Vafa to move this to the status of a theorem. How far is this situation now? Is there something certain that could be stated about? Besides, there also should be numerical attempts in the direction to confirm the conjecture. What is the literature about, if any? This conjecture is something like an important pillar of string theory, much like supersymmetry. If this is the situation (a failure in Maldacena's conjecture is a failure of string theory) then it should be properly emphasized. Finally, I would support this FA nomination as this is becoming a key aspect in a large part of physics and this is properly pointed out in the article. It is possible that all this matter will end up like the bootstrap model in the sixties, I do not know, but due to the relevant role it has now, an article like this is overdue. Better if so well written and presented.--Pra1998 (talk) 17:10, 28 October 2013 (UTC)[reply]

Comment: coming here at request from Polytope24. I think this article is darn close to the FA criteria, but not quite yet. (The GA status is well deserved, and the recent editors are to be applauded.) I agree with other commenters who note that the article is now comprehensive, well researched, and neutral. I also think the overall structure/style is fine. Things that I think should be fixed up:

Criteria 1a: there are scattered first-person pronouns ("we" and "our") in the form of the polite construction which includes the reader. WP:MOS allows these despite their non-encyclopedic style, but indicates that alternative sentence structures are preferred if possible. I think that most (not all) of the occurrences here can be fixed up quite easily without using "we" or "our".
Criteria 4: I'm sorry to say that the absolutely lovely level of detail, which appears to have been encouraged in previous edits, leaves the article too long. Perhaps I'm wrong. However, I do believe that the well-written "History and Development" section gets off topic, and is more like a history of holography in general than a history of AdS/CFT specifically.

Spatrick99 (talk) 17:13, 28 October 2013 (UTC)[reply]