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Background independence talks at Strings 06

  1. Zero: business as usual

    50.0%
  2. One: ray of hope

    16.7%
  3. Two or more: spells breakthrough

    33.3%
  1. Aug 14, 2005 #1

    marcus

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    In the list of talks on the program for Strings 06, how many titles do you expect will mention background independence?

    Looking at the Strings 05 program, you see this year the number is ZERO
    http://www.fields.utoronto.ca/programs/scientific/04-05/string-theory/strings2005/speakers.html

    if you want to inspect slides from the talks, or listen to audio, look here
    http://www.fields.utoronto.ca/audio/05-06/#strings

    The words "background independent" or "nonperturbative" occur in NONE of the titles.

    But to persuade yourself that a NONZERO number is a possible outcome, look at the talk Hirosi Ooguri gave
    http://www.fields.utoronto.ca/audio/05-06/strings/ooguri/
    the title is Topological String Theory and on slide #37, right at the end, Ooguri says

    "What is topological string theory?...
    A background independent formulation is desired.
    Perhaps a better understanding of topological M theory in 7 dimensions will help."

    This might have been a reference to a recent Lee Smolin paper, which is about topological M theory in 7 dimensions, and tries using LQG methods to quantize it.

    Had Smolin had been invited and agreed to give a talk, he might well have chosen to present this recent paper hep-th/0503140
    A quantization of topological M theory
    which he describes on page 3, paragraph 1, as making
    "a first attempt at such a background independent quantization of topological M theory."

    Personally I think it would be of considerable importance were several leading string people to actively address the problem of a B-independent (or in a broad sense nonperturbative) formulation. How many talks at Strings 06 will say background independent or nonperturbative in the title?

    Zero: business as usual
    One: ray of hope
    Two or more: spells breakthrough
     
  2. jcsd
  3. Aug 14, 2005 #2

    marcus

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    this is the correct thread,
    there was a glitch of some sort that occurred with posting the other thread, and I hope someone will kindly remove the defective version.
    this thread is what I intended to post

    thanks
     
  4. Aug 14, 2005 #3

    marcus

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    Here is a quote from the introduction of http://arxiv.org/hep-th/0503140
    A quantization of topological M theory
    which Smolin describes on page 3, paragraph 1, as making
    "a first attempt at such a background independent quantization of topological M theory."

    ---quote Smolin---
    Approaches to quantum gravity have so far fallen into two broad classes, according to whether they are background independent or background dependent. So far most work on string and M theory has been based background dependent methods and ideas. But it has long been acknowledged that this was a temporary expedient and that the ultimate principles of string theory must be formulated in background independent terms.

    Meanwhile, a great deal of progress has been made on background independent approaches, including loop quantum gravity[1, 2] , causal sets[3] and lorentzian dynamical triangulations[4].

    The results of these, especially loop quantum gravity (LQG), have inspired a few attempts to approach string or M theory from a background independent perspective[5, 6]. These make use of one of the most powerful observations of LQG, which is that theories of gravity are closely related to topological field theories[2]. The precise relation is that gravitational theories are constrained topological field theories. This means that their action is a sum of the action for a BF theory, plus quadratic constraints. These are sometimes called theories of forms, because the metric information is coded into the dynamics of forms[7, 8]. This is true of general relativity in all dimensions[9], as well as of supergravity in 11 dimensions[5], so it is a fact that must be relevant for how we formulate M theory.

    Recently Dijkgraaf et al[12] proposed a form of topological M theory, which is a seven dimensional theory which is hypothesized to unify two six dimensional theories called topological string theories. This theory is defined by an action proposed by Hitchin[10, 11], and involves only the dynamics of a three-form in seven dimensions. Dijkgraaf et. al. in fact propose that this theory is related by dimensional reduction to topological field theories relevant for three and four dimensional theories. This makes it natural to suggest that the quantization of Hitchin’s theory may be accomplished by using background independent methods which have been successfully applied to topological theories and theories of forms in lower dimensions...

    ---end quote---

    Dijkgraaf and Smolin are both invited speakers at the October Loops 05 conference in Potsdam.
    http://loops05.aei.mpg.de/
    http://loops05.aei.mpg.de/index_files/Programme.html


    I suppose that the topic of a background independent formulation of string theory will come up at that conference, perhaps in more than one of the talks.

    Thus I would judge that Loops 05 is already quite likely to satisfy the condition that the poll asks about concerning next year's String 06 conference---it may have one, or even more, talks about the prospects for B-indep string theory.
     
    Last edited: Aug 14, 2005
  5. Aug 14, 2005 #4

    Kea

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    Hi Marcus

    I couldn't choose any of the options. I think the answer is 'none', but not because it will be business as usual. On the contrary, some of the stuff the M-theorists are doing will finally sink in, but the term 'background independence' is too vague to make the title of a technical paper.

    Kea :smile:
     
  6. Aug 14, 2005 #5

    marcus

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    I'm glad to have a forecast about just what I was asking, Kea :smile:.
    I put down Zero for you (as my response)
    The Strings 06 conference doesnt have to be "business as usual" in other relevant ways you allude to, but since Zero would be the same as last year, no change in that indicator, it would be business as usual in that sense. That is what all I had in mind, so I count you as predicting zero.

    You may well be right, there may well be no talk with "Nonperturbative" or with "Background Independent" in the title. I would say that some string theorists obviously hear these terms as technical because they use them, but you may be right in suspecting that many of them have nothing but vague associations with the words "nonperturbative" and "background independent". the terms may well be, as you say, "too vague to make the title of a technical paper" among string theorists. I really can't say.
     
  7. Aug 14, 2005 #6

    Kea

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    OK. I voted zero. :smile:
     
  8. Aug 14, 2005 #7

    marcus

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    Kea, I suspect that an important paper in this respect is by Dijkgraaf et al.
    I will get the link
    http://arxiv.org/hep-th/0411073
    Topological M-theory as Unification of Form Theories of Gravity
    Robbert Dijkgraaf, Sergei Gukov, Andrew Neitzke, Cumrun Vafa
    65 pages, 2 figures
    "We introduce a notion of topological M-theory and argue that it provides a unification of form theories of gravity in various dimensions. Its classical solutions involve G_2 holonomy metrics on 7-manifolds, obtained from a topological action for a 3-form gauge field introduced by Hitchin. We show that by reductions of this 7-dimensional theory one can classically obtain 6-dimensional topological A and B models, the self-dual sector of loop quantum gravity in 4 dimensions, and Chern-Simons gravity in 3 dimensions. We also find that the 7-dimensional M-theory perspective sheds some light on the fact that the topological string partition function is a wavefunction, as well as on S-duality between the A and B models. The degrees of freedom of the A and B models appear as conjugate variables in the 7-dimensional theory. Finally, from the topological M-theory perspective we find hints of an intriguing holographic link between non-supersymmetric Yang-Mills in 4 dimensions and A model topological strings on twistor space."

    these are prominent people, I wonder if they use those terms anywhere here, and if so if it is in a vague or a precise sense. It is not the kind of paper I ordinarily look at, but I will check it out.
     
    Last edited: Aug 14, 2005
  9. Aug 14, 2005 #8

    marcus

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    Look, already at the top of page 5
    "Of course, topological M-theory should provide an, as yet not well-defined, nonperturbative definition of topological string theory. "
     
  10. Aug 14, 2005 #9

    Kea

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    Yes, I'm aware of this paper. I give them 1 or 2 years to work out there's an awful lot of category theory lurking behind these results. I just wish they'd hurry up. The LHC will be turned on soon, and these guys are much better at calculating stuff than me.

    Kea o:) :devil:
     
  11. Aug 14, 2005 #10

    marcus

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    I see that Dijkgraaf et al say "nonperturbative" several times, at least these instances:
    top of page 5 (in introduction)
    bottom of page 6
    middle of page 15
    top of page 47
    bottom of page 55 (in conclusions)

    there may be other instances, so for better or worse they are (as one would certainly expect) very aware of the concept and it is not too vague or un-technical for them to be using.

    I guess it is not too much of a stretch to imagine someone using the term in the title of his/her paper presented at Strings 06. Mainly just a matter of increasing awareness of the issues around B.I. and B.D. and perturbative/nonperturbative.

    I see that in the Dijkgraaf et al paper, the acknowledgements section thanks Lee Smolin for discussions.

    I think Smolin is making a potentially important contribution to Stringery by pushing for a background independent formulation, or for a nonperturbative formulation. I think his paper "Quantization of Topol. M Theory" should be getting a reading by people like Dijkgraaf, Vafa. To my mind it is not out of the realm of possibility that Smolin will deliver a paper at String 06. that would mean that the issues around background independent formulation would be becoming more prominent.
     
  12. Aug 14, 2005 #11

    Kea

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    You might well be right. Perhaps the poll should have a proviso: except for papers from BIQG people...
     
  13. Aug 14, 2005 #12

    marcus

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    but it doesnt.. I don't see one anyway.

    besides Smolin has published plenty of string research papers hasnt he?
    I think he qualifies as a string theorist. it is not an either-or thing obviously (a mathematician shd be able to do algebraic geometry sometimes and also other times category )
     
  14. Aug 15, 2005 #13

    Chronos

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    I think there will be at least one controversial BI discussion / presentation. It's not for certain, but, I have a pretty good source. Just curious, Kea: isn't Dr. Wiltshire attending that conference?
     
    Last edited: Aug 15, 2005
  15. Aug 15, 2005 #14

    marcus

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    Chronos says one or more---at this time he is not willing to decide which of the two alternatives to predict: "one" or "two or more".

    SelfAdjoint says "one"

    The rest of us (Kea, Entropy, me) are saying "zero"

    Chronos I hope that you will decide your prediction in due course---and please do register it!
     
    Last edited: Aug 15, 2005
  16. Aug 15, 2005 #15

    Kea

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    Which conference would you be referring to, Chronos?

    Kea :smile:
     
  17. Aug 15, 2005 #16

    marcus

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    Yay! Ohwilleke estimates that there may be TWO or more papers at Strings 06 which have the word "nonperturbative" or the words "background independent" in the title.

    Update:

    Ohwilleke says "two or more"

    SelfAdjoint says "one"

    The rest of us (Kea, Entropy, me) are saying "zero"

    Chronos has not yet registered his prediction on the actual poll, but has indicated he is more apt to agree with SelfAdjoint and Ohwilleke than with the rest of us.
    ------------------

    I would be happy if Ohwilleke turns out to be right about this. Keep in mind that these words don't necessarily mean the same thing to everybody or in every context. But having them in the title of one of the conference talks would at least indicate awareness of the issues. And in my view, having two or more talks at the conference directed towards formulating a nonperturbative B.I. version of string theory would signal a real sea change. But although it would be great I am not too hopeful of it happening.
     
    Last edited: Aug 15, 2005
  18. Aug 16, 2005 #17

    Chronos

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    I firmly believe there will be at least 2 np papers.
     
  19. Aug 16, 2005 #18

    marcus

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    you astonish me Chronos

    Update:

    Chronos and Ohwilleke say "two or more"

    SelfAdjoint says "one"

    The rest of us (Kea, Entropy, me) are saying "zero"


    ------------------

    I would be happy if Chronos and Ohwilleke turn out to be right about this, although we should keep in mind that "nonperturbative" and "background independent" don't necessarily mean the same to everybody and in every context. That said, I think that having them in the titles of talks at a major conference would promote awareness that the issues need resolution. They've been on hold for some years, while having lip service paid to them.
     
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