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fables [2020/03/09 15:33]
fables [2020/05/10 17:37]
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 2316:30BattelleMaciej Zdanowicz (EPFL)+ 
 +  2020, Wednesday, May 20, 16:00 (CEST), Virtual seminar, Lionel Lang (Stockholm University) 
 +Meeting ID: 592 872 9514  Password: (the number of lines on a cubic surface) 
 +**Co-amoebas, dimers and vanishing cycles** 
 +In this joint work in progress with J. Forsgård, we study the topology of maps P:(\C*)^2 \to \C given by Laurent polynomials P(z,w).  
 +For specific P, we observed that the topology of the corresponding map can be described in terms of the co-amoeba of a generic fiber. When the latter co-amoeba is maximal, it contains a dimer (a particularly nice graph) whose fundamental cycles corresponds to the vanishing cycles of the map P. For general P, the existence of maximal co-amoebas is widely open. In the meantime, we can bypass co-amoebas, going directly to dimers using a construction of Goncharov-Kenyon and obtain a virtual correspondence between fundamental cycles and vanishing cycles. 
 +In this talk, we will discuss how this (virtual) correspondence can be used to compute the monodromy of the map P. 
 +  2020, Tuesday, April 7, 17:00, Virtual seminar (EDGE seminar) Grigory Mikhalkin (Geneva) 
 +Meeting ID: 870 554 816 Password: 014504  
 +**Area in real K3-surfaces** 
 +Real locus of a K3-surfaces is a multicomponent topological surface. The canonical class provides an area form on these components (well defined up to multiplication by a scalar). In the talk we'll explore inequalities on total areas of different components as well a link between such inequalities and a class of real algebraic curves called simple Harnack curves. Based on a joint work with Ilia Itenberg. 
 +  2020, Monday, March 3117:00Virtual seminarVladimir Fock (Strasbourg) 
 +Meeting ID: 737 573 471
-**Beauville--Bogomolov decomposition in characteristic p>0**+**Higher measured laminations and tropical curves**
-The classical Beauville--Bogomolov decomposition is a structural result concerning complex varieties with trivial first Chern class.  It states that such varieties can be decomposed, up to finite étale cover, into a product of simpler building blocks: abelian, Calabi--Yau  and hyperkähler varieties In the talk, I will first briefly explain how varieties with trivial first Chern class arise in algebraic geometry, and how to obtain the decomposition theorem using differential geometry methods.  Then I will present recent result, obtained in a joint work with Zsolt Patakfalvi (EPFL), providing weak version of the decomposition in characteristic p>0 geometry where standard analytic techniques are not available.+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 groupThis notion generalises the notion of the ordinary 
 +integral measured lamination and on the other hand of tropical 
 +curve and can be constructed out of integral Lagrangian submanifold 
 +of the cotangent bundle.
 ---- ----
-  2020, Monday, March 16, 16:30, Battelle, Alexander Veselov (Loughborough University)[POSTPONED TILL APRIL]+  2020, Monday, March 16, 16:30, Battelle, Alexander Veselov (Loughborough University)[POSTPONED]
 **On integrability, geometrization and knots** **On integrability, geometrization and knots**
fables.txt · Dernière modification: 2021/10/28 22:32 de kalinin0