Thursday, April 26, 2018
Time  Items 

All day 

3pm 
04/26/2018  3:00pm to 4:00pm Let Vd,n⊂(Pd)n be the Zariski closure ofthe set of ntuples of points lying on a rational normal curve. The variety Vd,n was introduced because it provides interesting birational models of \barM0,n: namely, the GIT quotients Vd,n // LSLd+1.In this talk our goal is to find the defining equations of Vd,n. In thecase d=2 we have a complete answer. Fortwisted cubics, we use the Gale transform to find equations defining V3,n union the locus of degenerate point configurations. We prove a similar result for d≥4 and n=d+4. This is joint work with Alessio Caminata, Noah Giansiracusa, and HanBom Moon. Location:
LOM 206

4pm 
04/26/2018  4:00pm A vampire and his paramour, a medusa, wish to rendezvous in a large museum. Alas, the vampire cannot abide any rooms with direct sunlight, while the medusa must stay away from any rooms with human occupants, lest she turn them to stone. Thankfully, there is a dark, unoccupied room. How can they be sure to visit the room at the same time? We’ll discuss the combinatorics of such discovery problems, drawing a connection to the Ramsey numbers and Cayley expander graphs. Location:
LOM 215
04/26/2018  4:00pm A vampire and his paramour, a medusa, wish to rendezvous in a large museum. Alas, the vampire cannot abide any rooms with direct sunlight, while the medusa must stay away from any rooms with human occupants, lest she turn them to stone. Thankfully, there is a dark, unoccupied room. How can they be sure to visit the room at the same time? We’ll discuss the combinatorics of such discovery problems, drawing a connection to the Ramsey numbers and Cayley expander graphs. Location:
LOM 215
04/26/2018  4:30pm to 5:30pm Symplectic duality, as defined by BradenLicataProudfootWebster, is an equivalence between categories of deformation quantization modules on certain pairs of holomorphic symplectic manifolds. Surprisingly all known symplectic dual pairs arise as Higgs and Coulomb branches of 3d N=4 supersymmetric quantum field theories. In this talk I would like to argue that symplectic duality, as formulated by BLPW, is just a shadow of a more fundamental equivalence between certain factorization categories. More precisely each 3d N=4 theory gives rise two topological field theories: the 3d Amodel and the 3d Bmodel. The factorization categories of line operators in these theories can be computed by compactifying on a circle where they look like ordinary 2d A/Bmodels on loop spaces. Then symplectic duality is a corollary of the equivalence between Amodel line operators in a theory and the Bmodel line operators in the mirror theory. When a 3d theory is equipped with an action of a reductive group G the category of Atype line operators carries an action of Dmod(G((t))) and the Btype line operators carry an action of QCoh(Loc_G(D^*)). This allows us to make a link between symplectic duality and the local geometric Langlands program. This work is joint with Philsang Yoo, Tudor Dimofte, and Davide Gaiotto. Location:
LOM 206
