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What's Ed Witten up to?

  1. Jul 20, 2010 #1
    Does his Geometric Langlands research have anything to do with real physics? Or has he basically turned into a pure mathematician? How do mathematicians value his research in recent years? Has he made significant discoveries in this area?
  2. jcsd
  3. Jul 21, 2010 #2
    I don't understand the obsession with Witten. Why do you care?
  4. Jul 21, 2010 #3
    He is a trendsetter -- his research interests may point to future directions
  5. Jul 21, 2010 #4


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    Witten's higest achievements are based on topological reasoning on low dimensions (up to 4 dimensions). So, you will always see him talking about chern simons theory, mostly in 3d, N=2 supersymmetric models in 4d (e.g. Seiberg-Witten duality), topological strings which are complex 3D, twistors strings lives in 3D complex space CP(3|R).

    This is a very convenient way to analyze String Theory because, for example, Calabi Yau manifolds ( the 6 other non "usual" dimensions), which are used to build particles and forces at low energy limits, can be identified with several of the above 3d complex (6d real, roughly) models.

    The case of Langlands on Witten's work, at least the impression I have, is trying to study a generalization, or mix, of t'Hooft and Wilson loops. Given that t'Hooft op works as dual (it encloses) to a Wilson loop, which is the path integral of a gauge field, but creates Dirac-string like singularities, you need to study how this singularities interact with such generalization. These singularities correspond to operators on the surface of the enclosing, so studying these operators is like studying the mix of these operators.

    These operators correspond to the study of cusps (Langlands), but also to the geometry of the generalization. These generalized space is in 4D, and has elements of 3d and 2d. So, it is a way to work out how different mathematical entities that makes up the above topological theories relate to each other.
  6. Jul 21, 2010 #5
    What are Witten's thoughts on LQG? His father Louis is a GR expert.
  7. Jul 21, 2010 #6


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    Some combination of worthless and not even wrong.
  8. Jul 21, 2010 #7
    Ouch. Do you have a link or reference?
  9. Jul 21, 2010 #8


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    Not really. But I don't really care. Beyond Standard model theories are like religion. IF you are a Buddhist, why would care about the dogmatic antics of the pope?
  10. Jul 21, 2010 #9
    Does it?

    How many people are working on Geometric Langlands stuff?
  11. Jul 21, 2010 #10
    What are his current views on Superstring Theory and M-Theory? Does he still work on them, rather has he made any significant observations to understand M-Theory since he realized its existence? Does believe that they provide or could provide a consistent and mathematically consistent framework for a Theory of Everything or has he come to realize that M-Theory isn't the definite theory to describe everything?
  12. Jul 21, 2010 #11
    I forgot the source, but after a rather recent talk on a non-stringy topic, one of the audience asked Witten, "but how about string theory?" Witten answered lightly, "oh, I still hope it has something to do with nature".
  13. Jul 21, 2010 #12
    (Off-topic) Though I don't know enough to judge for myself, I take Witten's departure from string theory as an ominous hint that string theory is losing appeal to even the most mathematically minded physicists (or maybe Witten just wants to broaden his scope of research, who knows). IMHO some of the more physically minded string theorists are on their route of becoming second-rate condensed matter physicists, based on my uneducated guess that their string-inspired techniques eventually would only have marginal impacts on the highly complex field of condensed matter physics. As a graduate student possibly going into string theory, these random thoughts keep disturbing me.
    Last edited: Jul 21, 2010
  14. Jul 22, 2010 #13


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    Witten has not departed from String theory people. I don't know where that rumor started, but it is incorrect.
  15. Jul 27, 2010 #14


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    Witten recently gave a public lecture (as recipient of this year's Isaac Newton medal--a prize awarded in the UK) in which he presented a bright picture of the promise of string research.

    The online video is here:
    http://www.yourphysics.org/resources/videos/lectures/page_44292.html [Broken]
    The hour lecture is in two 30 minute parts.

    In case anyone is curious, here are links to the 21 papers he has posted
    on arxiv during the past five years---2006 to 2010.

    A short audio interview (about 5 minutes) with a journalist is here:
    The interview occurs as a segment of a longer program, between minutes 15:30 and 20:20.
    He presents the anthropic multiverse idea.

    It may not matter very much, what that one researcher is doing and what he says in public. But in any case I think the best thing is to look at available facts and decide for yourself what the person in question is up to.
    Last edited by a moderator: May 4, 2017
  16. Jul 28, 2010 #15


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    For me it is a weakness of a theory if it is accepted only because it is constantly promoted by some luminaries. QM became a fast-selling item even after some inventors expressed their scepticism.

    If the success of string theory depends on Witten's (instead of physical) assessments something is wrong with string theory. So if Witten becomes more reluctant or hesitant it's up to the other experts in the field and up the theory to proof its usefulness.

    In that sense Witten's ideas - and how the community reacts - are important.
  17. Jul 28, 2010 #16


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    I realize its not obvious to outsiders, so you will just have to take my word for it, but a lot of the work that comes out of Princeton/IAS HEP groups are large collaborations of theorists, all exchanging ideas and bouncing calculations off the wall at each other.

    So much so that its not entirely obvious who really coauthored paper x or paper y because the credit really lies with 30 or 40 additional people.

    Witten (and a few other big shots) is one of the heads of this process, and has been for a long time despite taking a sabbatical now and then. Which is why if you actually read stringy or HEP research papers, you'll notice the authors frequently cite him for valuable talks.

    This is not accidental, and is systematically organized. In fact; it has led to some criticism in the past because its often been said that Witten and his people specialize in fast physics.

    Anyway, people are free to email him if they really want to satiate their curiosity, but to those hoping to score some silly points against string theory, prepare to be dissappointed.
  18. Jul 28, 2010 #17


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    Of course I take your word.

    Anyway: as there are rumours that string theory is going south, that it falls short of its pledge, that Witten becomes uninterested, ... it would be nice to see some of its latest achievements and new research directions.

    Is there a community asking themselves honestly about long-term goals in string theory? I saw some talks and papers from David Gross adressing fundamental issues, but he seems to be the exception - of course that's my perception as an outsider!

    I would really be happy to compile a short list of such questions (always sticking to facts!) and await your response.

  19. Jul 28, 2010 #18
    I've emailed him about his views on LQG but he didn't reply. If I were Witten, and I wanted to secure my legacy, I'd hedge my bets and invest in a theory of QG that does NOT make use of SUSY nor higher dimensions, since right now there's no evidence for these, and LHC may not provide that evidence.
    Last edited: Jul 28, 2010
  20. Jul 28, 2010 #19
    let's see the questions
  21. Jul 28, 2010 #20
    I would say "equations" or "mathematical expressions", instead of "calculations". Most string theory papers that I have seen do not have "calculations" in the sense of the word, that is, with concrete numbers put into formulas.
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