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Cambridge Noncommutative Geometry workshop in September

  1. Jul 11, 2006 #1

    marcus

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    http://www.newton.cam.ac.uk/programmes/NCG/ncgw02l.html

    Alejandro Rivero is listed. Maybe arivero will report to this forum some of what is discussed!

    I see also that Laurent Freidel will be there.


    the subtitle, besides "NGC and Physics", is Fundamental Structure of Space and Time

    it would be a good place to announce the publication by Cambridge Press of Oriti's book (if it is ready) since the title is right: Approaches to Quantum Gravity: towards a new understanding of space time and matter.

    the workshop is sponsored by Templeton wealth.

    here is the main page
    http://www.newton.cam.ac.uk/programmes/NCG/ncgw02.html

    information thanks to "nonblogger" at Woit's blog
    http://www.math.columbia.edu/~woit/wordpress/?p=428#comment-13379
     
    Last edited: Jul 11, 2006
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  3. Jul 11, 2006 #2

    arivero

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    My plan is to use the move to relax some months from blog addiction but OK I could do space for a little report. The goal of the whole semester goes beyond the workshop, I hope that to give a push to the research on NCG.
     
  4. Jul 16, 2006 #3

    marcus

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    You have no idea what dismay this announcement causes the fellow addicts.

    so you will attend realworld seminars and colloquia at cambridge and slack off on bloggery?

    don't even think of doing such a thing!
    you should always be amphibious and live in both environments.
    this way you can be our spy in cambridge---I can't imagine a better place to have a correspondent.
     
  5. Aug 29, 2006 #4

    arivero

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    Just a note to tell that I have landed in the town some days before of the workshop, so if someone is coming early too then feel free to email me to "al.rivero" in gmail and we can go for a cup of coffee the Sunday or the Saturday.
     
  6. Aug 29, 2006 #5

    marcus

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    Hey hey HEY! Our man in Cambridge :biggrin:

    You are the one person we can be sure will write curious reports and reflections from there. Observation is such a habit with you that you will not be able to resist. I would love to be in Cambridge. Thanks in advance---looking forward to hearing more.
     
    Last edited: Aug 29, 2006
  7. Sep 1, 2006 #6

    arivero

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    Amazingly Lubos Motl, from the other Cambridge, has been the first one reporting about the meeting :tongue2:

    I refer, of course, to his review of Connes paper, which is the paper to be discussed Monday afternoon.
     
    Last edited: Sep 1, 2006
  8. Sep 4, 2006 #7

    arivero

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    we are on it. Please check the timetable to tell me if you are interested on some concrete talk
     
  9. Sep 4, 2006 #8

    marcus

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    I'm more interested in which talks you choose to attend and find worthwhile. Many look like a gamble---they might pan out and turn up an idea to take away, or they might not.

    If I could be there for just one day (aside from today, of course, which has Alain Connes), I would choose Wednesday:


    09:00-10:00 Penrose, R (Oxford)
    Spin-networks, twistors, cosmology and all that

    10:00-11:00 Laemmerzahl, C (ZARM, University of Bremen)
    Experimental search for quantum gravity effects

    11:30-12:30 Taylor, AN (Edinburgh)
    The standard cosmological model

    14:00-15:00 Heller, M (Vatican Observatory)
    A noncommutative closed Friedman world model

    15:30-16:30 Barrett, J (University of Nottingham)
    The physics of three-dimensional quantum gravity

    16:30-17:00 Goldin, G (Rutgers University)
    Local current algebras for deformed quantum mechanics with fundamental length scales


    Now that I look, I see lots of chance for disappointment! Sorry to say this. Recently when I heard Penrose lecture it seems to me largely froth and clever drawings----witty cartoons of speculative ideas---humor.
    A kind of infuriating entertainment that left me with no hope for the future.

    At least John Barrett is talking about WORK. His talk is supposed to cover 4 papers of his from past years, like 2002-2005. One could object and say that this is "old" but I would be glad to get a subjective feel for his state of mind about what his line of investigation has accomplished and what the prospects are for extension to 4D. what does he say about work in progress?

    I am just afraid that Claus Lämmerzahl will also be superficial and frustrating. Experimental test ideas for QG are almost the most important thing one can be thinking about. One could go to the talk expecting hard specifics, and he could just stay on a level of generality and say "oh yes these effects will be very tiny so they will be quite hard to detect!" I saw no reference to specifics in his abstract.

    There are lots of teas and dinners. Maybe the informal discussions will be among the most valuable parts. I hope fervently that you find some intriguing and surprising aspects to share with us.
     
    Last edited: Sep 4, 2006
  10. Sep 4, 2006 #9

    arivero

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    Today talk has been basically an straightforward presentation of friday paper. He has shown some of the computations, which will be published in a longer paper with Chamseddine. Connes his working idea is that this discrete spectral triple could be just the tip of the iceberg of a more complicated space as one increases energy, and then he is not worried that if used at the GUT scale his calculations run down to a top mass about 10% higher than experimental. He is of course very fond of being able of fitting the neutrino mass and keep Poincare Duality in the axioms at the same time.

    The iceberg is speculated to be some kind of quantum group kind of q-Poincare or so. A big no to fit Calabi Yau manifolds (some people in the audience asked for more concrete puns against string theory but they were only partly satisfied).

    Talks are recorded so I supposse it will be available, but anyway everything was in the preprint.

    As for Barret, Connes is trying to trick him either to an extra talk or to change topic, at least he launched a "we will see tomorrow" referring to http://arxiv.org/abs/hep-th/0608221
     
  11. Sep 4, 2006 #10

    marcus

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    It seem that both Barrett and Connes arrived at the same important insight at right about the same time. I posted their two papers abstracts on biblio-thread
    https://www.physicsforums.com/showpost.php?p=1074833&postcount=512
    https://www.physicsforums.com/showthread.php?p=1074833#post1074833

    It would make sense for them both to present their latest work at this conference. And for Barrett not to be self-effacing like some Grisha but to come right out with it----and I am glad that Connes is urging him.

    On Woit's blog, when they discussed Susskind's analogy of the boats floating or not floating, I heard you ask quietly if he had said anything about Archimedes. (It would mean understanding what will float instead of trial and error.) The question came across quite funny in the context.
     
    Last edited: Sep 4, 2006
  12. Sep 5, 2006 #11

    arivero

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    Today we had had QED as breakfast... I mean, first lecture was Kreimer and thus his continuing program on the study of the renormalisation group. I suppose he was addressing some non perturbative tricks, but I can not judge.

    About Archimedes, I provoked it both in Woit and Motl blogs because it is a very evocative figure when ships and physics are mixed :-)
     
  13. Sep 12, 2006 #12

    arivero

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    Three extra lectures were given the Monday after the workshop. Sitarz spoke about his examples of ncg on spheres and Barrett did a detailed, pretty understable, review of his model. It was sort of intimate lectures, down to 15-18 persons in the gatehouse seminar, not the big one, so no mp3 is available. I took my notes using a iRex iLiad tablet, which unfortunately generates pnm files instead of more common WindowsPC formats. So I have uploaded the notes to http://www.flickr.com/photos/72166458@N00/241378310/ and ff.
     
  14. Sep 12, 2006 #13

    arivero

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    It was exactly as promised. He stressed some distinction between spin-networks, discrete, and twistors, complex holomorphic things. In the last talk he went about some conformal trick and a funny cosmological process for periodic universes. Or perjaps just a "witty cartoon of speculative ideas", as you say.

    As I said elsewhere, very amusing transmutation of Heller from mathematician in the morning to theologician in the Evening. At that time, btw, he did some interesting remarks on God and the Demiurgue.

    It was deep and frustrating. He had a very elegant powerpoint and went across almost every running experiment (except Uncle Al :wink: one?) testing any side of gravitational theory. But he run very slowly and in a very tricky way he arranged for the most interesting slides to be shown at the end of the talk, thus strealing time from the next speaker. I think it was in part intentional, given the good general desing of the talk. Besides Pionner annomaly he mentioned some other ones in launching of satelites or something so.
     
  15. Sep 12, 2006 #14

    arivero

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    The "web seminar" page, which amounts to a series of MP3 files, is here: http://www.newton.cam.ac.uk/webseminars/pg+ws/2006/ncg/ncgw02/

    I strongly suggest downloading Connes MP3 as an alternative to hear usual podcasts :-) For the hurried people, some interesiting passages are:

    -the starting ten minutes. Around minute 7-8 there is some reference to Tomita theory.
    -about 00:33 some reference to gravity results by Reuter (??) as a posible origin of the dimension of the spectral triple.
    -about 00:37-00:39 and ff some discussion about the posible q-group origin of the spectral triple
    -about 00:41-00:42 a slight, discarded, possibility of lepton quark mising is aluded.
    -in 52..53 the use of the tadpole constant
    -at 1:02 about symplectic random matrices as (a, other) possibility for the physics origin, or the physics at Planck scale or so, because it follows...
    ... at 1:06 some discussion on Newton contant and scale.
    -At 1:13.40, the assertion that Calabi Yau objects are not expected here.
    -at 1:25 ?
    -at 1:35 a final comparision with string theory, asked by the public
     
    Last edited: Sep 12, 2006
  16. Sep 12, 2006 #15

    Kea

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    Thanks, arivero. I finally sat down and listened to the whole thing. I found it much more helpful than the short paper. Really excellent. Nice to see that he was quite enthusiastic about symplectic matrix models (which we all know is about twisted ribbon graphs), and also that he stressed again and again the two option idea, namely (a) buying a car that runs up to a certain speed (b) buying a car that can do anything!

    Exciting times.
    :smile:
     
    Last edited: Sep 13, 2006
  17. Sep 12, 2006 #16

    marcus

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    paper by M. Khovanov just posted on arxiv. QA section.
    braids, might be of interest (e.g. to Kea). put link in biblio-thread
     
    Last edited: Sep 13, 2006
  18. Sep 13, 2006 #17

    arivero

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    Probably most people will find my notes are unreadable. This is partly because of sloopiness on my side, partly because I have not calibrated myself to write into a Wacom tablet yet (actually, an iRex electronic ink tablet with a Wacom under). But really the talk went straightforward, "rectopalante" as we say in spanish :biggrin: Barrett left open the epsilon, epsilon' coefficients Connes use to implement J and gamma, and used the Minkowskian Dirac operator plus the requeriment of the physical states to be positive eigenstates of said J, gamma, to avoid in this way the Fermion doubling and to get the usual solutions of Dirac equation. Then the values of epsilon, epsilon' become fixed from whole consistency requeriments.

    I found Barrett very didactical, even after years of playing with these models.
     
  19. Sep 13, 2006 #18

    marcus

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    Thanks for posting your notes. I found the series of 9 slides----in an approximate sense they matched up with Barrett's paper so even though I could not follow the notes they gave me an idea of the scope of his Monday 11 September talk.

    As an afterthought from this Newton Institute conference (listening to some MP3 audio and hearing about it from you) I wanted to find out more about the QG group in the Maths department at Nottingham

    http://www.maths.nottingham.ac.uk/QG/seminars.html

    it seems small and relatively uneventful but in the Spring 2006 term they had seminars by Kirill Krasnov, John Barrett, and (guest) Aristide Baratin.
     
  20. Sep 13, 2006 #19

    arivero

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    You have a good instinct! Even if it is by now a small group in the local, they seem to have great prospectives in the global: Barret took the opportunity during the workshop to explain they were about organising some of these european "research networks".
     
  21. Sep 13, 2006 #20

    marcus

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    enjoyed reading this blog of Paul Cook for two reasons

    http://ppcook.blogspot.com/2006/09/penrose-universe.html

    One is his account of Penrose new cosmology idea

    Other is some anecdotes from the Cambridge NCG workshop
    especially about how Alain Connes comported himself at the Thursday evening panel discussion

    it is a long blog and the anecdotes are towards the end
    ===========

    Paul Cook links to your (Arivero's) report and your Barrett notes at the beginning of his blog
     
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