Seminar: Symplektische Geometrie / Symplectic Geometry — Sommersemester 2018, HU Berlin

This is a working group seminar run by Chris Wendl (and normally also Klaus Mohnke, but he is on sabbatical this semester) on recent developments in symplectic geometry. Participants normally are expected to be familiar with the basics of symplectic geometry, including some knowledge of holomorphic curves and/or Floer-type theories. The seminar is conducted in English.

From the second meeting onward, the seminar this semester meets on Mondays at 15:00 (c.t.) in room 1.315 (Rudower Chaussee 25).

Tuesday April 17, 2018
11:00-13:00 (c.t.)
RUD 25, Room 4.007
discussion of topics
Monday April 23, 2018
15:00-17:00 (c.t.)
RUD 25 Room 1.315
no seminar
Monday April 30, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
no seminar
Monday May 7, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Agustin Moreno
Topic: Donaldson hypersurfaces
Monday May 14, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Agustin Moreno
Topic: Donaldson hypersurfaces (continuation)
Monday May 21, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
no seminar
Tuesday May 22, 2018
11:00-13:00 (c.t.)
RUD 25, Room 1.315
Speaker: Agustin Moreno
Topic: Donaldson hypersurfaces (the final battle)
Wednesday May 23, 2018 Jo Nelson in the Differential Geometry and Geometric Analysis seminar
Monday May 28, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
no seminar
Monday June 4, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
no seminar
Monday June 11, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Chris Wendl
Topic: Some remarks on transversality and symmetry
Abstract: Transversality results are frequently needed in differential topology and many related fields: common examples include the lemma that generic smooth functions satisfy the Morse condition, or that generic sections of a vector bundle are transverse to the zero-section so that their zero-sets are submanifolds. But such statements typically become problematic if the data are required to satisfy symmetry conditions: as a rule, one cannot have transversality and symmetry at the same time. I will explain in this talk what the precise nature of this problem is, and how to recognize when it can be solved. As a test case, I will sketch a proof that for any smooth manifold with a smooth action of a finite group G, generic smooth G-invariant functions are Morse.
Monday June 18, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
no seminar
Monday June 25, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Felix Schmäschke
Topic: Closed Geodesics on Orbifolds
Abstract: The study of closed geodesics on Riemannian manifolds is a very old and renowned field of Riemannian geometry and in particular the question of the existence of at least one closed geodesic on a compact Riemannian manifold has been answered positively by Lyusternik and Fet with a proof in 1951. The same question for Riemannian orbifolds however, initially studied by Guruprasad and Haefliger in 2006, turns out to be surprisingly difficult and up to this day remains open, despite the fact that orbifolds are just a mild generalization of manifolds and often exhibit similar properties. In the talk I reprove and slightly improve the results by Guruprasad and Haefliger using an alternative approach. This is a joint project with Luca Asselle.
Monday July 2, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Klaus Niederkrüger (Lyon)
Topic: Exotic tight contact structures on Euclidean spaces
Monday July 9, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Felix Schmäschke
Topic: TBA
Monday July 16, 2018
15:00-17:00 (c.t.)
RUD 25, Room 1.315
Speaker: Jonathan Bowden (Monash University)
Topic: From Foliations to Contact Structures
Abstract: In the mid 90's Eliashberg and Thurston established a fundamental link between the more classical theory of (smooth!) foliations and that of contact topology in dimension 3, which, amongst other things, played an important role in Mrowka and Kronheimer's proof of the Property P Conjecture. Their theory gains its potency from the fact that Gabai gave a powerful method for constructing (smooth) taut foliations on (irreducible) 3-manifolds from non-trivial homology classes. On the other hand most foliations that occur in nature via (pseudo)-Anosov flows, surgery, gluing, blow ups... are not smooth in general. This naturally motivates the need to apply Eliashberg and Thurston's theory to foliations of lower regularity. In this talk I will report on how (and hopefully why) their theory generalises. Time permitting I will discuss some applications and related questions.

last semester's symplectic seminar