Past Geometry and Analysis Seminar

17 November 2014
14:15
Andras Szenes
Abstract

 I will report on recent work on a tropical/symplectic approach to the Horn inequalities. These describe the possible spectra of Hermitian matrices which may be obtained as the sum of two Hermitian matrices with fixed spectra. This is joint work with Anton Alekseev and Maria Podkopaeva.

  • Geometry and Analysis Seminar
10 November 2014
14:15
Marco Gualtieri
Abstract

I will describe a generalization of toric symplectic geometry to a new class of Poisson manifolds which are
symplectic away from a collection of hypersurfaces forming a normal crossing configuration.  Using a "tropical
moment map",  I will describe the classification of such manifolds in terms of decorated log affine polytopes,
in analogy with the Delzant classification of toric symplectic manifolds. 

  • Geometry and Analysis Seminar
20 October 2014
14:15
to
16:30
Mark Gross
Abstract
I will discuss joint work with Ludmil Katzarkov and Helge Ruddat. Given a hypersurface X in a toric variety of positive Kodaira dimension, (with a certain number of hypotheses) we construct an object which we believe can be viewed as the mirror of X. In particular, it exhibits the usual interchange of Hodge numbers expected in mirror symmetry. This may seem puzzling at first. For example, a curve of genus g would be expected to have a mirror such that h^{0,0}=g, which is not possible for a variety. However, our mirror is a singular scheme Y along with a perverse sheaf F, whose cohomology carries a mixed Hodge structure. It then makes sense to compute Hodge numbers for F, and we find the traditional exchange of Hodge numbers.
  • Geometry and Analysis Seminar

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