Joseph Chuang, City,
        University of London
    
    
    
    Rank functions on triangulated
      categories.
    
     
    A rank function is a nonnegative
      real-valued, additive, translation-invariant function on the
      objects of a triangulated category satisfying the triangle
      inequality on distinguished triangles. One way to obtain a rank
      function is as the mass of a Bridgeland stability condition, but
      rank functions may exist in the absence of t-structures. Rank
      functions on the perfect derived category of a ring are related to
      Sylvester rank functions on finitely presented modules, and
      therefore, via the work of Cohn and Schofield, to representations
      of the ring over skew fields. This is joint work with Andrey
      Lazarev.