June 22-June 26 Kaoru Ono(Kyoto University) TBA Bai-Ling Wang (Australian National University) Title: Lectures on virtual orbifold techniques for Gromov-Witten moduli spaces Abstract: In these four lectures, we will explain the basic ingredients in applying the virtual orbifold techniques for Gromov-Witten type moduli spaces, based on the joint work of Bohui Chen, Anmin Li and the speaker. Lecture 1: we will discuss the gluing principle for the moduli spaces of stable curves using a notion of horocycle structures on the universal curves. Lecture 2, we will define a notion of weak Lie groupoids and apply this notion to get a virtiual orbifold system from a topological orbifold Fredholm systems under some mild assumptions. Lecture three, we will apply the tools from Lecture 1 & 2 to get a virtiual orbifold system for the moduli space of stable maps in a closed symplectic manifold. In the final lecture, we will discuss the orientation issue for virtiual orbifold system and explain how this can be applied to define the cohomological Gromov-Witten invariants. If time permits, we will also discussion an on-going work of Bohui Chen, Jianxun Hu and the speaker on the K-theoretical Gromov-Witten invariants. Dingyu Yang (Institut de Math ?ematiques de Jussieu - Paris Rive Gauche) Title: Polyfolds and sc-analysis in Gromov-Witten theory. Abstract: Hofer-Wysocki-Zehnder’s theory of polyfolds is a powerful and rigorous framework, and is arguably the right language to do infinite dimensional analysis on varying domains, and one of its applications is to smoothly and canonically describe various moduli spaces in symplectic geometry in full generality and achieve transversality. The key ideas behind it are conceptually simple and elegant. It offers several nice features such as minimal artificial choices made, a global nature, similarity to the usual Fredholm theory, and completely separating analysis aspects from transversality and algebra. The latter means that most of theory should be transferrable/quotable to myriad of moduli spaces in symplectic geometry without semipositivity assumption, which are subtly different in setting and choices of algebra, but share similar essential features. Polyfold theory is also compatible with other virtual machineries. To achieve all that, polyfold theory starts with a new notion of a smooth map, a local model and Fredholmness right off the bat. To make the learning curve less steep, this mini course will motivate the polyfold philosophy and get some working knowledge and illustration from Gromov-Witten theory (http://arxiv.org/abs/1107.2097). This hopefully will demystify this particular virtual technique, and encourage the use of polyfold as a tool to try to generalize works from less general settings, and also provide some prerequisite for the forthcoming SFT polyfold paper. Bin Zhang (Sichuan University) TBA June 28-July 1 Kenji Fukaya(SCGP) Title:Wehrheim - Woodward functoriality by Lekili - Lipyanskiy technique Abstract:In this talk I will explain a way to realize the project initiated by Wehrheim – Woodward to construct a functor from the category of symplectic manifold (with Lagrangian correspondence as a morphism) to the category of filtered A infinity categories. Our construction is based on Lekili - Lipyanskiy's idea in their paper Adv. Math. 236 (2013) and uses Akaho - Joyce's Floer theory of immered Lagrangian submanifold. Note there is another (interesting) works of this problem which is due to Bottman-Wehrheim. Their method uses strip shrinking and figure 8 bubbles and is different from one I will explain in this talk. (They however both are based on the fundamental idea by Wehrheim - Woodward.) Weiping Li (Oklahoma State University and Southwestern Jiaotong University) TBA Dingyu Yang (Institut de Math ?ematiques de Jussieu - Paris Rive Gauche) Title: How does polyfold theory fit with other virtual techniques. Abstract: We will take a look at the relationship of polyfold theory with some of (hopefully all) 7 or so other proposed virtural techniques in symplectic geometry, and hopefully provide some unity among various perspectives. Li Guo(Rutgers University) TBA Huijun Fan (PKU) Title: A mathematical theory of Gauged linear sigma model Abstract: GLSM is an important unified theory in 2-d TFT and mirror symmetry, which was proposed by Witten in 90's. Recently, due to the rapid development in Landau-Ginzburg model the mathematical realization of GLSM becomes an realistic and important program. In the past several years, Fan-Jarvis-Ruan have made some important progress in the related moduli problem from the side of algebraic geometry and meanwhile the side of differential geometry. In this minicourse, I will report our progress in this direction. The minicourse will talk about the analytical theory of GLSM and consists of the following parts: 1. Geometrical and analytical setting. (including moment map, connection theory) 2. The gauged Witten equation (Related perturbed symplectic Vortex equations and some important examples) 3. Slice theorem, Index theorm 4. Compactness theorem. Yoel Groman(Hebrew University) Title:Floer theory on open manifolds Abstract:I will discuss a recent construction which allows the definition of Floer theoretic invariants for tame symplectic manifolds. As an application I will discuss a computation of zeroth symplectic cohomology for the complement of an anticanonical divisor in toric Calabi Yau manifolds. The result fits nicely with predictions arising from mirrror symmetry. Xiaobo Liu (PKU) Title: Connecting the Kontsevich-Witten and Hodge tau-functions by the Virasoro operators. Abstract: Kontsevich-Witten tau-function and the Hodge tau-function are generating functions for two types of intersection numbers on moduli spaces of stable curves. Both of them are tau functions for the KP hierarchy. In this talk, I will describe how to connect these two tau-functions by differential operators belonging to the $\widehat{GL(\infty)}$ group. Indeed, these two tau-functions can be connected using Virasoro operators. This proves a conjecture posted by Alexandrov. This is a joint work with Gehao Wang. Bai-Ling Wang (Australian National Universty) Title: Orientifold Gromov-Witten theory Abstract: Motivated by applying the virtual orbifold techniques to other moduli problem, Bohui Chen and I made some progresses in the Gromov-Witten theory for orientifolds. Orientifolds, and a genarliazed of orbifolds, have been promoted by physicists to the study of string theory for unoriented strings. In this talk, we explain what symplectic orientifolds are and how to establish Gromov-Witten theory on any symplectic orientifold. Bohan Fang(PKU) Title:Mirror B-model for toric Calabi-Yau 3-folds Abstract: I will discuss, by examples, the mirror curve of a toric Calabi-Yau 3-fold (including oribfolds). In particular, I will explain the mirror curves around the large radius limit, and the family of mirror curves over the toric variety of the secondary fan. This is the B-model set-up in BKMP (Bouchard-Klemm-Marino-Pasquetti) remodeling conjecture, and the understanding of the global B-model behavior is a requirement to apply this conjecture to many interesting examples, e.g. modularity of Gromov-Witten invariants and all genus crepant resolution conjecture. Remark:an invitation letter (in Chinese) with dates 06/26-07/08 of my visit to Sichuan University Hiroshi Ohta (Nagoya University) Title:The trace map in cyclic $A_{\infty}$ category Abstract: Based on my joint works with K. Fukaya, Y-G. Oh, K. Ono and partially with M. Abouzaid, I will introduce and discuss the trace map in cyclic $A_{\infty}$ category, especially from the point of view of Frobenius manifold structure. Hui Ma (Tsinghua Unversity) Title: Lagrangian intersection of the Gauss images of isoparametric hypersurfaces Abstract: The Gauss image of an isoparametric hypersurface in the unit sphere is a compact minimal Lagrangian submanifold embedded in the complex hyperquadric. In this talk, we will discuss the Hamiltonian non-displaceablity of such monotone Lagrangian submanifolds in complex hyperquadrics. The talk is based on a joint work with Hiroshi Iriyeh, Reiko Miyaoka and Yoshihiro Ohnita. Yong-Geun Oh (IBS, Postech) Title: Bulk deformations, tropicalizations and non-displaceable Lagrangian toric fibers. Abstract: In this talk, I will first explain how we can deform Lagrangian Floer homology by cycles from the given ambient symplectic manifold, and apply this to Lagrangian torus fibers of toric manifolds. Then we will characterize what FOOO call `bulk-balanced Lagrangian torus fibers' as the intersections of certain collection of tropical curves selected purely in terms of the associated moment polytope. This talk is based on a joint work with Fukaya-Ohta and Ono (for the first part), and also on the work of ! Weiwei Wu(CRM, University of Montreal) Title: Dehn twists exact sequences through Lagrangian cobordism. Abstract: In this talk we first introduce a new "singularity-free" approach to the proof of Seidel's long exact sequence, including the fixed-point version. This conveniently generalizes to Dehn twists along Lagrangian submanifolds which are rank one symmetric spaces and their covers, including RP^n and CP^n, matching a mirror prediction due to Huybrechts and Thomas. Cheol-Hyun Cho (Seoul National Unversity) TBA Kaoru Ono (Kyoto University) TBA Xiaojun Chen (Sichuan University) TBA Wei-Ping Li (HKUST) Title: Master Spin Fields on the Quintic. Abstract: The Gromov-Witten invariants are essentially the counting of the number of genus g curves in a compact complex manifold. It originated in 1990’s from the mirror symmetry of the string theory,a physical theory trying to unit everything in high-energy physics. The GW invariants of the qunitic, which is the zero locus of a degree 5 homogenous polynomial of 5 variables in the four dimensional projective space, is one of the most famous research topics from the very first day of mirror symmetry to today. There is another physical theory for the polynomial mentioned above, called Landau-Ginzburg theory. Physicists conjectured that these two theories can be identified via some mysterious transformations. The mathematical foundation of the LG-theory was established by Fan-Jarvis-Ruan, in which the invariants analogous to GW-invariants are also defined by them and called FJRW invariants. Master Spin Field theory is a mathematical attempt to unlock the mysterious link between GW-invariants and FJRW-invariants. It is an on-going joint work with H.L. Chang, J. Li and Melissa Liu. Yi Lin (Georgia Southern University) Title:The Hard Leschetz Property for contact manifolds Abstract: In the literature, there are two different versions of Hard Lefschetz theorems for a co mpact Sasakian manifold. The first more classical version, due to Kacimi-Alaoui, asserts that the basic cohomology of a compact Sasakian manifold satisfies the Hard Lefschetz property. The second version , established far more recently by Cappelletti-Montano, De Nicola, and Yudin, holds for the De Rham cohomology of a compact Sasakian manifold. In this talk, we will di scuss a new approach to the Hard Lefschetz theorem for Sasakian manifolds using th e formalism of odd dimensional symplectic geometry. It leads to a Hard Lefschetz t heorem for the more general $K$-contact manifolds, which immediately implies that the two exis ting versions of Hard Lefschetz theorem are mathematically equivalent to each other. Our method sheds new insights on the topology of a Sasakian manifold. For instance, we will discuss how to use it to construct simply-connected $K$ contact manifolds w hich do not support any Sasakian structures in any dimension greater than or equal to seven. This in particular answers an open question asked by Boyer and late Galicki. I f time permits, we will also discuss some recently discovered new topological obstruc tions to the existence of a Sasakian metric. Shaofeng Wang(PKU) Title: Constructing virtual Euler cycles and classes Abstract: In 2006 Guangcun Lu and Gang Tian constructed (virtual) Euler cycles over stratified Banach manifolds (orbifolds) in the general abstract setting. In this talk we replace “quasi-transversal” assumption in their paper with “semi-stable” assumption and reconstruct Euler cycles in manifold cases. This weakened assumption is easier to verify and the process of construction has potential to wide use. Changzheng Li(IBS) Title: A special Lagrangian fibration on a complex Grassmannian of two planes Abstract: We study the complex Grassmannian Gr(2, n) of two plane equipped with a meromorphic volume form which has simple pole along a specified anti-canonical divisor -K. We construct a special Lagrangian fibration on the complement of -K in Gr(2, n). This is my joint work with Kwok Wai Chan and Naichung Conan Leung. Yongbin Ruan (PKU) TBA