Overview

An international conference covering a broad range of recent developments in symplectic geometry, open to all interested participants.

Confirmed Speakers

Mohammed Abouzaid
Mohammed Abouzaid
Stanford University
Cengiz Aydin
Cengiz Aydin
Heidelberg University
Aleksander Doan
Aleksander Doan
University College London
Yoel Groman
Yoel Groman
Hebrew University of Jerusalem
Yusuf Barış Kartal
Yusuf Barış Kartal
National University of Singapore
Yoosik Kim
Yoosik Kim
Pusan National University
Grigory Mikhalkin
Grigory Mikhalkin
University of Geneva
Alex Oancea
Alex Oancea
University of Strasbourg
Kaoru Ono
Kaoru Ono
Kyoto University
Pedro Salomão
Pedro Salomão
Southern University of Science and Technology
Kazushi Ueda
Kazushi Ueda
University of Tokyo
Jun Zhang
Jun Zhang
University of Science and Technology of China

Program

Sessions will run Tuesday–Friday (Nov 25–28).

Note: This schedule is tentative and is likely to change closer to the conference date.

Tuesday, Nov 25
09:00–09:30 Registration
09:30–10:30 Talk 1: Kaoru OnoA symplectic fixed point theorem in the presence of infinite fundamental group
Abstract

Abstract will appear here.

10:30–11:00 Coffee Break
11:00–12:00 Talk 2: Grigory MikhalkinTotally real rational functions of degrees g and g-1 on real curves of genus g
Abstract

A real function is totally real if the inverse image of any real value consists entirely of real points. Such a function gives an (unramified) covering of the real locus over the circle. Kummer and Shaw have introduced the "separating semigroup" of a real curve consisting of all possible multidegrees appearing in this way. We overview what is known on this semigroup, paying a special attention to the elements of degree equal to the genus of the curve and those less by one. Based on a joint work in progress with Stepan Orevkov.

12:00–14:00 Lunch
14:00–15:00 Talk 3: Yoel GromanClosed strings and the reconstruction problem in mirror symmetry
Abstract

Consider a symplectic Calabi-Yau manifold which is either closed or geometrically bounded and which is equipped with a Maslov 0 Lagrangian torus fibration with singularities of simple Gross-Siebert type. The existence of such fibrations on anti-canonical hypersuraces in toric varieties has recently been announced by Matessi et al. In this setting I will discuss work in progress on a solution to the reconstruction problem in mirror symmetry which is based on symplectic cohomology with supports on invariant subsets of the fibration. A feature of this construction is that it leads to an explanation of closed string mirror symmetry.

15:00–15:30 Coffee Break
15:30–16:30 Talk 4: Yoosik KimCluster algebras and monotone Lagrangian tori
Abstract

In this talk, I will discuss one application of cluster algebras to symplectic geometry. Using the cluster algebra structure on unipotent cell and the existence of nice basis of the homogeneous coordinate ring of partial flag varieties, we construct monotone Lagrangian tori in partial flag varieties. We also present a convenient criterion, derived from properties of the dual canonical basis, for proving the existence of infinitely many distinct monotone Lagrangian tori. As an application, we show that whenever the corresponding cluster algebra is of infinite type, the associated family of monotone Lagrangian tori contains infinitely many distinct objects. This talk is based on joint work with Yunhyung Cho, Myungho Kim, and Euiyong Park.

Wednesday, Nov 26
09:30–10:30 Talk 5: Kazushi UedaSolid quasicoherent sheaves and homological mirror symmetry
Abstract

Homological mirror symmetry is originally formulated by Kontsevich as a conjectural equivalence between the derived Fukaya category of a Calabi-Yau manifold and the derived category of coherent sheaves on its mirror. If the symplectic form is irrational, then there are no compact Lagrangian submanifolds, and if the complex structure is general, there are only few coherent sheaves, so that these categories contain little information. In the talk, we will discuss speculations on a generalization of the Fukaya category consisting of noncompact Lagrangian submanifolds with solid local systems, which should be mirror to solid quasicoherent sheaves.

10:30–11:00 Coffee Break
11:00–12:00 Talk 6: Jun ZhangHamiltonian shape invariant and its quantitative applications
Abstract

In this talk, we introduce a non-linear symplectic capacity for 4-dimensional Euclidean domains $X$, known as the shape invariant of $X$, which describes the embeddability of product Lagrangian tori into $X$. We will present a computational framework for this invariant using techniques from symplectic field theory. Furthermore, we explore its applications in uncovering new obstructions to symplectic embeddings and detecting Hamiltonian knottedness of Lagrangian tori. This talk is based on joint work with Richard Hind.

Thursday, Nov 27
09:30–10:30 Talk 7: Alex OanceaDynamics in cotangent bundles via symplectic homology with differential graded coefficients
Abstract

I will start by presenting the recent construction of symplectic homology with differential graded coefficients, as developed in joint work with Barraud, Damian and Humilière. I will then present applications to dynamics in cotangent bundles of closed manifolds that are not aspherical.

10:30–11:00 Coffee Break
11:00–12:00 Talk 8: Mohammed AbouzaidRevisiting Contact Homology
Abstract

I will discuss joint work in progress with Zhengyi Zhou towards understanding how to lift contact homology to a bordism-valued invariant.

12:00–14:00 Lunch
14:00–15:00 Talk 9: Yusuf Barış KartalGeneralized homology and symplectic cohomology
Abstract

Symplectic cohomology of a Liouville manifold is not very sensitive to its topology: the homology of the manifold can be arbitrarily complicated while its symplectic cohomology vanishes. However, it has been shown that, by remembering the circle action and the filtration on it, one can recover the rational homology of the underlying manifold, by a filtered version of the Tate cohomology. On the other hand, this construction loses the torsion information in homology. In this talk, we show how to recover further information about the homotopy type of the underlying symplectic manifold, including torsion part of its homology, complex K-theory and Morava K-theory from enhanced versions of symplectic cohomology and the structures on it, via a modified Tate construction. This is joint work with Laurent Cote.

15:00–15:30 Coffee Break
15:30–16:30 Talk 10: Aleksander DoanHolomorphic curves, gauge fields, and Cauchy-Riemann operators
Abstract

It is a long-standing open problem to generalize sheaf-counting invariants of complex projective three-folds to symplectic manifolds of real dimension six. One approach to this problem involves counting J-holomorphic curves, for a generic almost complex structure J, with weights depending on J. Various known symplectic invariants can be expressed as such weighted counts. In this talk, based on joint work with Thomas Walpuski, I will discuss a new construction of weights associated with curves and a closely related problem on the structure of the space of Cauchy-Riemann operators on a Riemann surface.

Friday, Nov 28
09:30–10:30 Talk 11: Cengiz AydinApplications of Conley-Zehnder Index to periodic orbits in the Hill problem
Abstract

In this talk I discuss two applications of Conley-Zehnder Index to periodic orbits in the framework of the spatial circular Hill three-body problem. (1) I demonstrate how to express lunar months in terms of Conley-Zehnder Indices and Floquet multipliers associated to Hill's lunar orbit. (2) I show how to use the Conley-Zehnder Index to analyze the network structure of symmetric periodic orbit families of the Hill problem. The extensive collection of families within this problem constitutes a complex network, fundamentally comprising the so-called basic families of periodic solutions, including the orbits of the satellite $g$, $f$, the libration (Lyapunov) $a$, $c$, halo and collision $\mathcal{B}_0$ families. Since the Conley-Zehnder Index leads to a grading on a topological bifurcation invariant, the local Floer homology and its Euler characteristic, the computation of those indices facilitates the construction of well-organized bifurcation graphs depicting the interconnectedness among families of periodic solutions.

10:30–11:00 Coffee Break
11:00–12:00 Talk 12: Pedro SalomãoFinite energy foliations in the restricted three-body problem
Abstract

In this talk I will explain the use of pseudo-holomorphic curves to study the circular planar restricted three-body problem. For mass ratios sufficiently close to 1/2 and energies slightly above the first Lagrange value, we show the existence of finite energy foliations whose binding orbits are two retrograde orbits around the primaries and the Lyapunov near the first Lagrange point. These foliations explain the existence of homoclinic orbits to the Lyapunov orbits. This is joint work with L. Liu.

Venue

Seoul National University
Seoul, South Korea

The talks will take place in 27-220 (i.e. building 27, room 220).

Practical Information

Organizers

Cheol-Hyun Cho
POSTECH
Jungsoo Kang
Seoul National University
Kyler Siegel
University of Southern California
Otto Van Koert
Seoul National University