symplectic
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symplectic [2022/05/02 14:59] – kalinin0 | symplectic [2023/11/09 23:30] – slavitya_gmail.com | ||
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===== GeNeSys: Geneva-Neuchâtel Symplectic geometry seminar ===== | ===== GeNeSys: Geneva-Neuchâtel Symplectic geometry seminar ===== | ||
+ | |||
+ | **2023, November 6, Monday, Université de Neuchâtel** | ||
+ | |||
+ | Prof. Dr. Emmanuel Opshtein (Université de Strasbourg) | ||
+ | 15:00, Université de Neuchâtel, Rue Emile-Argand 11, Room B217 | ||
+ | Liouville polarizations and their Lagrangian skeleta in dimension 4 | ||
+ | | ||
+ | In the simplest framework of a symplectic manifold with rational symplectic class, a symplectic polarization is a smooth symplectic hypersurface Poincaré-Dual to a multiple of the symplectic class. This notion was introduced by Biran, together with the isotropic skeleta associated to a polarization, | ||
+ | |||
+ | ------------- | ||
+ | **2023, April 26, Wednesday, Université de Genève** | ||
+ | |||
+ | Lionel Lang (Gävle) | ||
+ | Measuring holes of hypersurfaces | ||
+ | 14h00 | ||
+ | |||
+ | In 2000, Mikhalkin introduced a class of real algebraic planar curves now known as simple Harnack curves. Among their many nice properties, these curves appear as spectral curves of planar dimers. In this context, Kenyon and Okounkov showed that any simple Harnack curve is determined by the logarithmic area of some well chosen membranes bounded on the curve (plus some boundary conditions). This is a very special situation since, in general, the areas of these membranes only provide local coordinates on the space of curves under consideration. In this talk, Lionel Lang would like to discuss a generalization of this fact to arbitrary dimension, namely how logarithmic volumes of well chosen membranes provide local coordinates on linear systems of hypersurfaces. Moreover, these local coordinates have an obvious tropicalization that gives rise to global coordinates on the corresponding linear system of tropical hypersurfaces. Eventually, if time permits, he would like to discuss potential applications to deformation of real algebraic hypersurfaces. | ||
+ | |||
+ | Viatcheslav Kharlamov (Strasbourg) | ||
+ | Unexpected loss of Smith-Thom maximality: the case of Hilbert squares of surfaces | ||
+ | 16h00 | ||
+ | |||
+ | Viatcheslav Kharlamov explores the maximality of the Hilbert square of maximal real surfaces, and finds that in many cases the Hilbert square is maximal if and only if the surface has connected real locus. In particular, the Hilbert square of no maximal K3-surface is maximal. Nevertheless, | ||
---------------- | ---------------- | ||
- | | + | |
- | | + | **2023, March 21, Tuesday, Université de Neuchâtel** |
+ | |||
+ | Patricia Dietzsch (ETH Zürich) | ||
+ | Dehn twists along real Lagrangian spheres | ||
+ | 14h00 | ||
+ | |||
+ | A major tool in the study of the Dehn twist along a Lagrangian sphere is Seidel' | ||
+ | |||
+ | Cheuk Yu Mak (University of Southampton) | ||
+ | Non-displaceable Lagrangian links in 4 manifolds | ||
+ | 16h00 | ||
+ | |||
+ | One of the earliest fundamental applications of Lagrangian Floer theory is detecting the non-displaceablity of a Lagrangian submanifold. Much progress and generalizations have been made since then but little is known when the Lagrangian submanifold is disconnected. In this talk, we describe a new idea to address this problem. Subsequently, | ||
+ | ---------------- | ||
+ | |||
+ | **2022, October 18, Université de Genève, salle 6-13** | ||
+ | |||
+ | |||
+ | Ilia Itenberg (Sorbonne) | ||
+ | Real enumerative invariants and their refinement | ||
+ | Salle 6-13, 14h15 | ||
+ | |||
+ | **Abstract: | ||
+ | |||
+ | The talk is devoted to several real and tropical enumerative problems. | ||
+ | We suggest new invariants of the projective plane (and, more generally, of toric surfaces) | ||
+ | that arise as results of an appropriate enumeration of real elliptic curves. | ||
+ | These invariants admit a refinement (according to the quantum index) similar to the one introduced by Grigory Mikhalkin in the rational case. | ||
+ | We discuss the combinatorics of tropical counterparts of the elliptic invariants under consideration and establish a tropical algorithm | ||
+ | allowing one to compute them. | ||
+ | This is a joint work with Eugenii Shustin. | ||
+ | ---------------- | ||
+ | **2022, September | ||
+ | |||
+ | |||
+ | Richard Hind (University of Notre Dame) | ||
+ | Obstructing Lagrangian isotopies | ||
+ | Room B107, 14:00 | ||
+ | |||
+ | **Abstract: | ||
+ | |||
+ | I will describe some obstructions to the existence of Lagrangian tori in subsets of Euclidean space, and also to isotopies between the tori. The obstructions come from holomorphic curves and In simple situations are sharp. As a consequence we can derive obstructions to certain 4 dimensional symplectic embeddings, which turn out not to be especially strong, but the analysis does lead to precise statements about stabilized ellipsoid embeddings. Results are taken from joint works with Emmanuel Opshtein, Jun Zhang and Kyler Siegel and Dan Cristofaro-Gardiner. | ||
+ | |||
+ | Joé Brendel (Université de Neuchâtel and Tel Aviv University) | ||
+ | Lagrangian tori in S^2 x S^2 | ||
+ | Room E213, 16:00 | ||
+ | |||
+ | **Abstract: | ||
+ | |||
+ | There is an obvious family of Lagrangian tori in $S^2 \times S^2$, namely those obtained as a product of circles in the factors. We discuss the classification of such product tori up to symplectomorphisms and note that the non-monotone case is qualitatively very different from the monotone one. In the proof, we use a symmetric version of McDuff' | ||
+ | |||
+ | ---------------- | ||
+ | 2022, July 15, Friday, Université de Genève | ||
+ | |||
+ | |||
+ | Kyler Siegel (University of Southern California) | ||
+ | |||
+ | "On the symplectic complexity of affine varieties" | ||
+ | |||
+ | Abstract | ||
+ | |||
+ | Symplectic topology is a framework for studying global features of spaces, lying somewhere between differential topology and algebraic geometry in terms of flexibility versus rigidity. In this talk we introduce a new notion of " | ||
+ | |||
+ | Welcome and lunch. 11h-14h | ||
+ | |||
+ | Lecture 1. 14h-15h | ||
+ | |||
+ | Lecture 2. 15h30. | ||
+ | |||
+ | |||
+ | ---------------- | ||
+ | 2022, April 29, Friday, Université de Neuchâtel | ||
+ | |||
Yakov Eliashberg (Stanford, visiting ITS-Zürich) | Yakov Eliashberg (Stanford, visiting ITS-Zürich) | ||
| | ||
Ligne 8: | Ligne 104: | ||
Abstract | Abstract | ||
+ | |||
Two years ago Ko Honda and Yang Huang proved a series of remarkable results concerning contact convexity in high dimension. | Two years ago Ko Honda and Yang Huang proved a series of remarkable results concerning contact convexity in high dimension. | ||
Unfortunately, | Unfortunately, | ||
While it follows the same overall strategy as Honda-Huang’s proof, | While it follows the same overall strategy as Honda-Huang’s proof, | ||
+ | |||
+ | Welcome and lunch. 12h-14h | ||
Lecture 1. 14h-15h | Lecture 1. 14h-15h | ||
+ | |||
Lecture 2. 15h30. | Lecture 2. 15h30. | ||
symplectic.txt · Dernière modification : 2023/11/27 17:55 de slavitya_gmail.com