|Date: Friday, October 02, 2015
Location: 4088 East Hall (3:10 PM to 4:00 PM)
Title: Total positivity for the Lagrangian Grassmannian
Abstract: The stratification of the Grassmannian by positroid varieties has a rich combinatorial theory. Positroid varieties are indexed by a number of interesting combinatorial posets, including k-Bruhat intervals and bounded affine permutations. In addition, Postnikov's boundary measurement map gives a family of parametrizations for each positroid variety; the domain of each parametrization is the space of edge weights of a weighted planar network.
In this paper, we generalize the combinatorics of positroid varieties to the Lagrangian Grassmannian, the moduli space of maximal isotropic subspaces with respect to a symplectic form.
Speaker: Rachel Karpman
Institution: U. Michigan