fables
Différences
Ci-dessous, les différences entre deux révisions de la page.
Les deux révisions précédentesRévision précédenteProchaine révision | Révision précédenteProchaine révisionLes deux révisions suivantes | ||
fables [2019/10/07 14:29] – weronika | fables [2020/03/31 13:00] – weronika | ||
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Ligne 4: | Ligne 4: | ||
The normal starting time of this seminar is 16.30 on Monday. | The normal starting time of this seminar is 16.30 on Monday. | ||
+ | 2020, Monday, March 31, 17:00, Virtual seminar, Vladimir Fock (Strasbourg) | ||
+ | | ||
+ | **Higher measured laminations and tropical curves** | ||
+ | |||
+ | We shall define a notion of a higher lamination - a graph embedded | ||
+ | into a Riemann surface with edges coloured by generators of an affine | ||
+ | Weyl group. This notion generalises the notion of the ordinary | ||
+ | integral measured lamination and on the other hand of a tropical | ||
+ | curve and can be constructed out of a integral Lagrangian submanifold | ||
+ | of the cotangent bundle. | ||
+ | |||
+ | ---- | ||
+ | |||
+ | 2020, Monday, March 16, 16:30, Battelle, Alexander Veselov (Loughborough University)[POSTPONED TILL APRIL] | ||
+ | |||
+ | **On integrability, | ||
+ | |||
+ | |||
+ | I will start with a short review of Liouville integrability in relation with Thurston’s geometrization programme, | ||
+ | using as the main example the geodesic flows on the 3-folds with SL(2, | ||
+ | |||
+ | A particular case of such 3-folds the modular quotient SL(2, | ||
+ | |||
+ | The talk is partly based on a recent joint work with Alexey Bolsinov and Yiru Ye. | ||
+ | |||
+ | ---- | ||
+ | |||
+ | 2020, Monday, February 17, 16:30, Battelle, Karim Adiprasito | ||
+ | (University of Copenhagen, Hebrew University of Jerusalem) | ||
+ | | ||
+ | ** Algebraic geometry of the sphere at infinity, polyhedral de Rham theory and L^2 vanishing conjectures ** | ||
+ | |||
+ | |||
+ | I will discuss a conjecture of Singer concerning the vanishing of L^2 cohomology on non-positively curved manifolds, and relate it to Hodge theory on a Hilbert space that arises as the limit of Chow rings of certain complex varieties. | ||
+ | |||
+ | ---- | ||
+ | |||
+ | |||
+ | |||
+ | 2019, Friday, December 6, 15:00, Battelle, Tomasz Pelka (UniBe) | ||
+ | ** Q-homology planes satisfying the Negativity Conjecture ** | ||
+ | |||
+ | A smooth complex algebraic surface S is called a Q-homology plane if H_i(S,Q)=0 for i>0. This holds for example if S is a complement of a rational cuspidal curve in P^2. The geometry of such S is understood unless S is of log general type, in which case the log MMP applied to the log smooth completion (X,D) of S is insufficient. The idea of K. Palka was to study the pair (X,(1/2)D) instead. This approach gives much stronger constraints on the shape of D, and leads to the Negativity Conjecture, which asserts that the Kodaira dimension of K_X+(1/2)D is negative. It is a natural generalization e.g. of the Coolidge-Nagata conjecture about rational cuspidal curves, which was recently proved using these methods by M. Koras and K. Palka. | ||
+ | |||
+ | If this conjecture holds, all Q-homology planes of log general type can be classified. It turns out that, as expected by tom Dieck and Petrie, they are arranged in finitely many discrete families, each obtainable in a uniform way from certain arrangements of lines and conics on P^2. As a consequence, | ||
+ | |||
+ | |||
+ | ---- | ||
+ | |||
+ | 2019, Monday, November 25, 16:30, Battelle, Felix Schlenk (UniNe) | ||
+ | ** (Real) Lagrangian submanifolds ** | ||
+ | |||
+ | We start with describing how Lagrangian submanifolds of symplectic | ||
+ | manifolds naturally appear in many ways: In celestial mechanics, integrable systems, symplectic geometry, and algebraic geometry. | ||
+ | We then look at real Lagrangians, | ||
+ | of an anti-symplectic involution. How special is the property of being real? | ||
+ | While many of the examples discussed above are real, we explain why the | ||
+ | central fibres in toric symplectic manifolds are real only if the moment polytope | ||
+ | is centrally symmetric. | ||
+ | The talk is based on work of and with Joé Brendel, Yuri Chekanov, and Joontae Kim. | ||
+ | |||
+ | ---- | ||
+ | |||
+ | |||
+ | 2019, Friday, November 8, 14:00, Battelle, Johannes Rau (University of Tübingen) | ||
+ | ** The dimension of an amoeba ** | ||
+ | |||
+ | Amoebas are projections of algebraic varieties in logarithmic coordinates and were originally introduced by Gelfand, Kapranov and Zelevinsky in their influential book. Based on some computation, | ||
+ | |||
+ | |||
+ | ---- | ||
2019, Monday, November 4, 16.30, Battelle, Pierrick Bousseau (ETH Zurich) | 2019, Monday, November 4, 16.30, Battelle, Pierrick Bousseau (ETH Zurich) | ||
- | ** Title: TBA ** | + | ** Quasimodular forms from Betti numbers** |
+ | |||
+ | This talk will be about refined curve counting on local P2, the noncompact Calabi-Yau 3-fold total space of the canonical line bundle of the projective plane. I will explain how to construct quasimodular forms starting from Betti numbers of moduli spaces of dimension 1 coherent sheaves on P2. This gives a proof of some stringy predictions about the refined topological string theory of local P2 in the Nekrasov-Shatashvili limit. Partly based on work in progress with Honglu Fan, Shuai Guo, and Longting Wu. | ||
- | + | ||
- | ---- | + | ---- |
2019, Monday, October 28, 16.30, Battelle, Ilia Itenberg, (Sorbonne University) | 2019, Monday, October 28, 16.30, Battelle, Ilia Itenberg, (Sorbonne University) |
fables.txt · Dernière modification : 2023/12/05 11:54 de slavitya_gmail.com