The seminar on mathematical physics will be held on Wednesday from 12 – 1:30pm in CMSA Building, 20 Garden Street, Room G10.
The list of speakers for the upcoming academic year will be posted below and updated as details are confirmed. Titles and abstracts for the talks will be added as they are received.
For a listing of Mathematical Physics Seminars held prior to the 20172018 academic year, please click here.
Date  Name  Title/Abstract 
090417  No Talk  
09112017  YuShen Lin (Harvad CMSA)  Title: From the Decomposition of PicardLefschetz Transformation to Tropical Geometry
Abstract: PicardLefschetz transformation tells the monodromy of a fibration with “good” singular fibres. In the case of fibres are Lagrangian in a symplectic $4$manifold, there is a natural decomposition of PicardLefschetz transformation into two elementary transformations from Floer theory. The idea will help to develop the tropical geometry for some hyperKahler surfaces. 
091817  Yoosik Kim (Boston University) 
Title: Monotone Lagrangian tori in cotangent bundles. Abstract: As an attempt to classify Lagrangian submanifolds and due to their importance in Floer theory, monotone Lagrangian tori have been got attention. In this talk, we provide a way producing monotone Lagrangian tori in the cotangent bundles of some manifolds including spheres or unitary groups. The construction is based on the classification of Lagrangian fibers of a certain completely integrable system on a partial flag manifolds of various types. We then discuss when their Floer cohomologies (under a certain deformation by nonunitary flat line bundles) do not vanish. This talk is based on joint work with Yunhyung Cho and YongGeun Oh. 
092717  YuWei Fan (Harvard) 
WeilPetersson geometry on the space of Bridgeland stability conditions Abstract: Inspired by mirror symmetry, we define WeilPetersson geometry on the space of Bridgeland stability conditions on a CalabiYau category. The goal is to further understand the stringy Kahler moduli space of CalabiYau manifolds. This is a joint work with A. Kanazawa and S.T. Yau. 
100417  Dingxin Zhang, Brandeis 
Title: <1 part of slopes under degeneration” Abstract: For a smooth family of projective varieties over a field of characteristic p > 0, it is known that the Newton polygon of fibers goes up under specialization. In this talk, we will show that when the family acquires singular members, the less than one part of the slopes of the Newton polygon goes up under specialization. This could be viewed as a characteristic p analogue of a simple phenomenon in Hodge theory. 
101117 
No Talk  
10182017  Nati Blaier, Harvard CMSA 
Title: Geometry of the symplectic Torelli group Abstract: This talk has two parts. In the first part of the talk, I will introduce the group of symplectomorphism and try to convince you that it is a very important object in symplectic topology by surveying some known structural results and drawing a comparison with the situation in the smooth and Kahler geometries as well as the world of lowdimensional topology. In the second part, I’ll discuss the symplectic Torelli group for higher dimensional symplectic manifolds, and an ongoing project to use GromovWitten theory to detect interesting elements. 
10232017
*Monday* 
Florian Beck, Universität Hamburg 
Hitchin systems in terms of CalabiYau threefolds. Abstract: Integrable systems are often constructed from geometric and/or Lietheoretic data. Two important example classes are Hitchin systems and CalabiYau integrable systems. A Hitchin system is constructed from a compact Riemann surface together with a complex Lie group with mild extra conditions. In contrast, CalabiYau integrable systems are constructed from a priori purely geometric data, namely certain families of CalabiYau threefolds. Despite their different origins there is a nontrivial relation between Hitchin and CalabiYau integrable systems. More precisely, we will see in this talk that any Hitchin system for a simplyconnected or adjoint simple complex Lie group is isomorphicto a CalabiYau integrable system (away from singular fibers). 
11012017
*12:30pm1:30pm* 
Chenglong Yu, Harvard Math 
PicardFuchs systems of zero loci of vector bundle sections Abstract: We propose an explicit construction for PicardFuchs systems of zero loci of vector bundle sections. When the vector bundle admits large symmetry, the system we constructed is holonomic. This is a joint work with Huang, Lian and Yau. 
11062017
*Monday* 
Pietro Benetti Genolini (Univ. of Oxford) 
Topological AdS/CFT Abstract: I will describe a holographic dual to the DonaldsonWitten topological twist of gauge theories on a Riemannian fourmanifold. Specifically, I will consider asymptotically locally hyperbolic solutions to Romans’ gauged supergravity in five dimensions with the fourmanifold as conformal boundary, and show that the renormalised supergravity action is independent of the choice of boundary metric. This is a first step in the direction of combining topological quantum field theory with the AdS/CFT correspondence. 
11132017
*Monday 12:30pm* *Room G02* 
Yusuf Baris Kartal (MIT) 
Abstract: One can construct the symplectic mapping torus for a given a symplectic manifold with a symplectomorphism and use the flux invariant to distinguish the mapping tori of maps of different order. The essential argument is that the flow in a certain direction have different periods depending on the order of the symplectomorphism. In this talk, we will introduce an abstract categorical version of the mapping torus associated to an $A_\infty$ category and an autoequivalence. Then, we will construct a family of bimodules analogous to the flow and discuss how to characterize it intrinsically and how to use it to distinguish different categorical mapping tori.

11222017  No Talk  
11292017  Amitai Zernik (IAS)  Computing the A∞ algebra of RP2m ↪ CP2m using open fixedpoint localization. Abstract: I’ll explain how to compute the equivariant quantum A∞ algebra A associated with the Lagrangian embedding of RP2m in CP2m, using a new fixedpoint localization technique that takes into account contributions from all the corner strata. It turns out that A is rigid, so its structure constants are independent of all choices. When m = 1 and in the nonequivariant limit, they specialize to give Welschinger’s counts of real rational planar curves passing through some generic, conjugation invariant congurations of points in CP2m. So we get a diagrammatic expression for computing Welschinger invariants, which I’ll demonstrate with some examples. Time permitting, I’ll discuss a formal extension to higher genus which satises string and dilaton. 
12062017  Sarah Venkatesh (Columbia)  TBA 