Speaker: Emily Clader (San Francisco State University)

Title: Sigma models and phase transitions

Abstract: The Landau-Ginzburg/Calabi-Yau (LG/CY) correspondence is a proposed equivalence between two enumerative theories associated to a homogeneous polynomial: the Gromov-Witten theory of the hypersurface cut out by the polynomial in projective space, and the Landau-Ginzburg theory of the polynomial when viewed as a singularity. Such a correspondence was originally suggested by Witten in 1993 as part of a far-reaching conjecture relating the "gauged linear sigma models" arising at different phases of a GIT quotient. I will discuss an explicit formulation and proof of Witten's proposal for complete intersections in weighted projective space, generalizing the LG/CY correspondence for hypersurfaces and introducing a number of new features. This is joint work with Dustin Ross.