[geometry-ml:00958] Miniworkshop at IPMU 11/16-17 (Shakleton's abstract added)

[Satoshi Kondo]

Dear colleagues:

We announce again the following miniworkshop at IPMU
(the Institute for the Physics and Mathematics of the Universe)
now with Shakleton's title and abstract.

Regards,

Satoshi Kondo (IPMU)
http://ipmu.jp/

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Workshop on Recent Advances in Mathematics at IPMU

Date:   Nov. 16-17, 2009
Place:  Seminar Room at IPMU Prefab B
Organizing Committee:  Alexey Bondal and Kyoji Saito

Program:

16 November (Mo)
 9:45 - 10:45     Yuichi Nohara
11:00 - 12:00     Sergei Galkin
14:00 - 15:00     Alex Bene
15:30 - 16:30     Alexander Getmanenko

17 November (Tu)
 9:45 - 10:45     Tathagata Basak
11:00 - 12:00     Paul Bressler
14:00 - 15:00     Mikael Pichot
15:30 - 16:30     Ken Shakleton


***** Title and Abstract of Talks *****

Yuichi Nohara:
Title: Toric degenerations of Gelfand-Cetlin systems
      and potential functions
Abstract: It is well known that a polarized toric variety is
      related to a moment polytope in two different ways,
      monomial basis and the moment map. In the case of flag manifolds,
      certain polytopes, called Gelfand-Cetlin polytopes, also appear
      in similar ways: the Gelfand-Cetlin basis, a basis of an
      irreducible representation; and the Gelfand-Cetlin system,
      a completely integrable system. Furthermore the flag manifold
      admits a degeneration into a toric variety corresponding to
      the Gelfand-Cetlin polytope. Kogan and Miller proved that
      the Gelfand-Cetlin basis can be deformed into monomial basis
      on the toric variety under the degeneration.
      We show that the Gelfand-Cetlin system can be deformed into
      a moment map on the toric variety. We also apply the result
      to disk counting and calculate the potential function for a
      Lagrangian torus fiber of the Gelfand-Cetlin system.
      This is a joint work with T. Nishinou and K. Ueda.

Sergei Galkin:
Ttitle: Landau-Ginzburg models of Fano varieties
Abstract: TBA

Alex Bene:
Ttitle: Feynman diagrams and mapping class representations.
Abstract: In this talk, I will review how elementary moves on fatgraphs,
    a type of Feynman diagram with cyclically oriented vertices
    arising in 2D quantum gravity, defines the so-called Ptolemy groupoid, which
    can be viewed as an enlargement of the mapping class group of a
    bordered surface.  This viewpoint allows for the possibility of
    certain mapping class representations to be "extended to the groupoid
    level."  I will discuss examples of such representations which have
    target a certain vector space generated by similar Feynman diagrams
    called Jacobi diagrams which have arisen in the field of finite type
    invariants and Chern-Simons theory.

Alexander Getmanenko:
Title: Towards proving existence of resurgent solutions of a linear ODE.
Abstract: The talk will be devoted to discussion of foundational issues
    in the mathematically rigorous hyperasymptotic, or
    "resurgent",theory of linear differential equations. We will look at
    Shatalov-Sternin's proof of existence of resurgent  solutions of a
    linear ODE and discuss the construction of analytic continuation to a
    common "Riemann surface'' of all terms of the von Neumann
    series appearing in their proof. A more modest statement will be
    presented that we could write up in a detailed and rigorous fashion.
    We will also mention possible applications of the theory.

Reference: arXiv:0907.2934

Tathagata Bassak:
Title: TBA

Paul Bressler:
Title: Deformations of gerbes

Mikael Pichot:
Title: Groups of intermediate rank.
Abstract: I will introduce countable
      discrete groups which interpolate
      the classical (integer) values of the
      rank, especially between rank 1
      and rank 2. This is joint work with
      S. Barre.

Ken Shakleton
Title: On the coarse geometry of Teichmueller space
Abstract: We discuss the synthetic geometry of the
     pants graph in comparison with the Weil-Petersson
     metric, whose geometry the pants graph coarsely
     models following work of Brock’s. We also restrict
     our attention to the pants graph of the 5-holed sphere,
     studying the Gromov bordification and the dynamics
     of pseudo-Anosov mapping classes.
===========================

You can check the location from
http://www.ipmu.jp/access/img/KashiwaCampusMap.png

The schedule of the seminar can be checked from
http://db.ipmu.jp/seminar/