Différences

Ci-dessous, les différences entre deux révisions de la page.

--- fables [2021/10/24 16:35] – kalinin0
+++ fables [2023/02/12 13:10] – kalinin0
@@ Ligne 1: / Ligne 1: @@
 ====== Séminaire "Fables Géométriques". ======
-The normal starting time of this seminar is 16.30 on Monday.
+----
+  Monday, February 27, 2023
+  room 6-13
+**15h00 — Evgeni Abakoumov (Paris/Eiffel U)**
+**Chui's conjecture аnd rational approximation**
+C. K. Chui conjectured in 1971 that the average gravitaional field strength in the unit disk due to unit point masses on its boundary was the smallest when these point masses were equidistributed on the circle. We will present an elementary solution to some weighted versions of this problem, and discuss related questions concerning approximation of holomorphic functions by simple partial fractions. This is joint work with A. Borichev and K. Fedorovskiy.
+**16h00 — Ferit Ozturk (Istanbul/Bosphorus U and Budapest/Renyi Inst)**
+**Every real 3-manifold admits a real contact structure**
+We survey our results regarding real contact 3-manifolds and present our result in the title.
+A real 3-manifold is a smooth 3-manifold together with an orientation preserving smooth involution, called a real structure.
+A real contact 3-manifold is a real 3-manifold with a contact distribution that is antisymmetric with respect to the real structure.
+The standard examples of real contact 3-manifolds are link manifolds of isolated, real analytic surface singularities.
+We show that every real contact 3-manifold can be obtained via contact surgery along invariant knots starting from the standard real contact 3-sphere.
+As a corollary we show that any oriented overtwisted contact structure on an integer homology real 3-sphere can be isotoped to be real.
+----
+  Monday, February 6, 2023
+:00, room 6-13
+**Sergey Finashin (Ankara)**
+**“Affine Real Cubic Surfaces”**
+Abstract: (A joint work with V.Kharlamov) We prove that the space of
+affine, transversal at infinity, non-singular real cubic surfaces has 15 connected components. We give a topological criterion to distinguish them and show also how these 15 components are adjacent to each other via wall-crossing.
+----
+  Thursday, June 16, 2022
+:00, room 1-07
+**Prof.  Yakov Eliashberg (Stanford)**
+**“Topology of spaces of Legendrian knots via Algebraic K-theory”**
+Abstract: The highly non-trivial stable homotopy groups of the Waldhausen’s
+h-cobordism space inject into the homotopy groups of spaces of appropriate Legendrian submanifolds. For instance,  there is  a  homotopically non-trivial 2-parametric family of Legendrian unknots in ${\mathbb R}^{2n+1}$ for a sufficiently large $n$. This is a joint work with Thomas Kragh.
+----
+  Fri 17.12.2021, 13h30, room 6-13
+  Andras Szenes
+**Diagonal bases and wall-crossings in moduli spaces of vector bundle**
+The idea  of the calculation of the Hilbert function of the moduli spaces of vector bundles on Riemann surfaces goes back to the works of Michael Thaddeus in the early 90’s.
+I describe joint work with Olga Trapeznikova where this plan is carried out in detail, which uses only basic tools of Geometric Invariant Theory and a combinatorial/analytic device introduced by myself: the diagonal basis of hyperplane arrangements.
 ----
   Nov 1, 16h15. Room 06-13
@@ Ligne 9: / Ligne 62: @@
   Vasily Golyshev (Moscow, Bures-sur-Yvette)
-**Modularity proofs via fibered motives**
-This is a report on joint work with Don Zagier, and joint work
+**Markov numbers in number theory, topology, algebraic geometry, and differential equations**
-in progress with Kilian Bönisch and Albrecht Klemm.
+I will explain how the Markov numbers arise in different mathematical
+disciplines, and sketch the links. A recent contribution will be discussed, too.
-The rigid Calabi-Yau threefolds that appear as conifold fibers
-in the hypergeometric Landau-Ginzburg models of Fano
-complete intersection fourfolds in [weighted] projective spaces
-are expected to be modular, but what is lacking is the
-construction of actual correspondences with Kuga-Sato
-threefolds. I will explain how the technique of fibered motives
-can be used to provide `opportunistic' modularity
-proofs for such fibers.
 ----