Subfactor Seminar

Spring 2010

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Organizers: Dietmar Bisch, Richard Burstein, Ionut Chifan, and Jesse Peterson

Fridays, 4:10-5:30pm in SC 1432

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• Date: 1/29/10

• Canceled due to inclement weather.

Date: 2/5/10

• Richard Burstein, Vanderbilt University
• Title: Enumeration of Bisch-Haagerup subfactors, I
• Abstract:
  Let G be a finite group, generated by finite subgroups H and K. Results
  of Bisch, Das and Ghosh imply that the 3-cocycles of G which vanish on H
  and K correspond to the standard invariants of certain group-type
  (Bisch-Haagerup) subfactors. I will describe a new method of
  enumerating such cocycles, allowing the enumeration of all
  Bisch-Haagerup subfactors with specified (small) principal graph.

Date: 2/11/10

• Colloquium Talk by Vaughan Jones, UC Berkeley.
  4:10-5:00 in SC 5211.

Date: 2/12/10

• Richard Burstein, Vanderbilt University
• Title: Enumeration of Bisch-Haagerup subfactors, II
• Abstract:
  Let G be a finite group, generated by finite subgroups H and K. Results
  of Bisch, Das and Ghosh imply that the 3-cocycles of G which vanish on H
  and K correspond to the standard invariants of certain group-type
  (Bisch-Haagerup) subfactors. I will describe a new method of
  enumerating such cocycles, allowing the enumeration of all
  Bisch-Haagerup subfactors with specified (small) principal graph.

Date: 2/13/10 – 2/14/10

• Shanks Workshop on Subfactors and Fusion Categories

Date: 3/12/10

• No Meeting. Spring break.

Date: 3/26/10

• Romain Tessera, École Normale Supérieure de Lyon
• Title: Filling loops in Lie groups
• Abstract:
  It is well known that in Lie groups the isoperimetric function grows at
  most exponentially.
  For nilpotent or semi-simple Lie groups, it grows polynomially, whereas
  for certain solvable Lie groups, it grows exponentially. We will
  discuss some recent progress on the problem of characterizing Lie groups
  with exponential isoperimetric function.

Date: 4/2/10

• Jesse Peterson, Vanderbilt University
• Title: W*-superrigidity for Bernoulli shift actions of property (T) groups, I (after A. Ioana)

Date: 4/16/10

• Jesse Peterson, Vanderbilt University
• Title: W*-superrigidity for Bernoulli shift actions of property (T) groups, II (after A. Ioana)

Date: 4/23/10

• Richard Burstein, Vanderbilt University
• Title: Generators for finite depth subfactor planar algebras
• Abstract:
  Following Kodilayam and Tupirani, I will show that any finite depth subfactor planar algebra is generated by a single element.

Date: NCGOA Seminar, Tuesday 5/4/10

• Pinhas Grossman, Cardiff University
• Title: Q-systems and the Asaeda-Haagerup subfactor
• Abstract:
  We will introduce the notion of a Q-system, due to Longo, and discuss
  applications to constructing new subfactors from known ones. In
  particular, we will discuss the construction of a new subfactor with
  index one larger than the Asaeda-Haagerup subfactor, and possible
  additional related ones. This is joint work with M. Asaeda. Time
  permitting, we will also discuss work in progress on classifying certain
  planar algebras associated to quadrilaterals of factors.

Date: 5/10/10 – 5/19/10

• NCGOA Spring Institute 2010 on von Neumann Algebras

End of Spring Semester.