SEMINAR ON SYMPLECTIC AND CONTACT GEOMETRY

Université Libre de Bruxelles

Second Semester 2006-2007

Monday 14:00-15:00

Room 2.NO.906


Monday, January 29th

Brussels-Cologne joint seminar, Université Libre de Bruxelles
NO building (Campus Plaine), 9th floor (2.NO.906).
Directions

  
13:00 Oliver Fabert (Munich/Zurich)
Counting trivial curves in rational symplectic field theory
Branched covers of trivial cylinders are the trivial examples for punctured holomorphic curves studied in symplectic field theory. However, in order to determine the contribution of these trivial curves to the SFT differential algebras, one has to perturb the Cauchy-Riemann equation. In this talk I illustrate why we always get a trivial count. As an important consequence it follows that the differential in rational SFT (and contact homology) is strictly decreasing with respect to the action filtration.

14:30 Skander Zannad (Nantes)
Laminations, branched surfaces and contact structures
Laminations are an intermediate between surfaces and foliations. In particular, essential laminations generalize both incompressible surfaces and tight foliations. The main topological result about essential laminations, is that the universal cover of a manifold of dimension 3 carrying an essential lamination is R3. To study laminations, branched surfaces appear to be useful objects. In this talk, we will give a sufficient condition for a branched surface to fully carry a lamination, giving a piece of answer to a problem D. Gabai. In an attempt to link the theory of contact structures to the theory of branched surfaces and laminations, we give a sufficient condition so that two contact structures forming a pair are carried by the same branched surface. We will see how this result may be used to get topological results.


Monday, February 26th

Stefan Hainz (Bonn)
Stability of symplectic capacities


It is a well known fact that for ellipsoids in Rn all "normed" symplectic capacities are equal. We compare the Gromov radius, the Hofer-Zehnder, and the cylindrical capacity by constructing symplecting embeddings by hand, to show that this remains true for C4-deformations of ellipsoids in R4.

Monday, March 5th

Brussels-Cologne joint seminar, Universität zu Köln
Math building (Weyertal 86-90), 2nd floor (Großer Hörsall).
Directions

  
13:00 Alberto Abbondandolo (Pisa)
A Morse complex for Lorentzian geodesics
14:30 Gerhard Knieper (Bochum)
Geodesic flows on manifolds of nonpositive curvature


Monday, March 12th

Petya Pushkar (Technion and Moscow State University)
Morse theory on manifolds with boundary



Monday, March 26th

Klaus Niederkrüger (ULB)
A class of non-fillable contact structures, following Presas (part I)



Monday, April 16th

Klaus Niederkrüger (ULB)
A class of non-fillable contact structures, following Presas (part II)



Monday, April 23rd

Brussels-Cologne joint seminar, Université Libre de Bruxelles
NO building (Campus Plaine), 9th floor (2.NO.906).
Directions

  
13:00 Josh Sabloff (Haverford)
Duality for Legendrian Contact Homology in Three Dimensions and Higher
Legendrian contact homology (LCH) is a powerful non-classical invariant of Legendrian submanifolds of contact manifolds. I will discuss the structure of the linearized LCH for knots and in higher dimensions: it turns out that linearized LCH splits into a summand that records the homology of the submanifold and a summand that obeys a version of Poincare duality. This result simplifies calculations, establishes a framework for analyzing cohomology operations on the linearized LCH, and contextualizes Ekholm, Etnyre, and Sullivan's proof of the Arnold conjecture for double points of exact immersed Lagrangians in R2n. The higher dimensional case is joint work with Tobias Ekholm and John Etnyre.

14:30 Tom Coates (Imperial College)
Mirror Symmetry and the Crepant Resolution Conjecture
I will explain how to use mirror symmetry to determine how genus-zero Gromov-Witten invariants of toric orbifolds are related to those of their crepant resolutions. A key ingredient is the genus-zero version of Givental's quantization formalism. This is joint work with Alessio Corti, Hiroshi Iritani, and Hsian-Hua Tseng.


Monday, April 30th

Otto van Koert (ULB)
Every contact manifold can be given a contact non-fillable structure



Monday, May 21st

Muriel Heistercamp (ULB)
Covering simple symplectic 4-manifolds by hand



Monday, June 4th

Otto van Koert (ULB)
Action filtration for contact homology and connected sums



Monday, June 11th

Yuri Chekanov (Moscow Center for Continuous Math Education)
Overtwisted contact structures on S3 and their homotopies



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First Semester 2006-2007
Next Semester :
First Semester 2007-2008


Maintained by Frédéric Bourgeois.