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Loop-String companionship at the 2008 Bad Honnef conference

  1. Jun 24, 2008 #1


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    This is definitely a Social Science thread because it deals with the rapidly changing relations between the string and non-string quantum gravity research communities.
    The changing picture admittedly stems from current theoretical physics developments, and it its apt to have repercussions on future research directions---so it is closely bound up with purely physics issues.

    Can't really understand the social network changes without reference to the physics. But here all I need to do is REPORT without exploring underlying causes.

    Look at this April 14-16 conference program:
    The PDF slides for many of the talks are available for download.
    I've bolded some of the talks that interested me to see listed.

    Titles :

    I. Adam: Superstring perturbation theory
    A. Ashtekar: Loop quantum cosmology: a status report
    R. Blumenhagen: The landscape of string vacua
    B. de Wit: Supergravity and M theory
    L. Freidel: Status of spin foam models
    S. Giddings: Black Holes, high energy scattering, and locality
    H. Hamber: Lattice quantum gravity
    M. Henneaux: Cosmological billiards and hidden symmetries of gravity
    C. Kiefer: Quantum Geometrodynamics: whence, whither?
    D. Marolf: Black Holes, AdS, and CFTs
    K. Meissner: Background independence: a particle physicist's view
    M. Reuter: Asymptotically safe quantum gravity
    K. Stelle: Finiteness (or not) of N=8 supergravity
    T. Thiemann: Loop quantum gravity

    Discussion/Summary: Ashtekar, Blau, Giddings, Reuter, Stelle

    Basically what's happening here is that Hermann Nicolai who directs the quantum gravity and unification wing at Max Planck Potsdam set up a conference on approaches to quantum gravity. And as a matter of course, he brought together non-string QG people with string and former-string folks. No big deal. Nicolai just thought they would benefit by talking to each other :biggrin:

    Giddings and Marolf are at Santa Barbara. Neither of them IIRC has been doing especially stringy research recently. Both of their research has tended to be on black holes lately, a good topic for quantum gravity. Marolf is an old collaborator of Ashtekar's.
    So I would not classify Giddings and Marolf as belonging to a string CAMP, although they have in the past both participated in a lot of stringy research. That is the thing that I see most obviously in the Bad Honnef conference program. An absence of camp mentality.

    Nicolai's own research has always been in string, but he makes is institute at Potsdam hospitable to several non-string QG efforts.
    Last edited: Jun 24, 2008
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  3. Jun 24, 2008 #2


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    Hamber, another of the speakers, is the regular co-author of Ruth Williams at Cambridge. Hamber and Williams do simplicial QG----closely allied to the triangulations approach of the Utrecht bunch: so-called CDT.

    Kiefer is something of a QG generalist, I think. He writes comprehensive review articles and compiles books covering several QG approaches.

    Martin Reuter is someone we have had several threads discussing at PF Beyond forum. He and Roberto Percacci and half a dozen others have developed the Asymptotic Safety approach to QG. It has had some remarkable successes recently and some of the results are in surprising agreement with CDT, concerning the structure and dimensionality of spacetime at microscopic scale.

    We have company. I have to go. Maybe I'll have some time to continue this later today.

    It is kind of a sea-change, and noticeably European in manner. Worth thinking about.
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