Université Libre de Bruxelles
Second Semester 2006-2007
Monday 14:00-15:00
Room 2.NO.906
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Monday, January 29th Brussels-Cologne joint seminar,
Université Libre de Bruxelles |
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| 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
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Monday, March 5th Brussels-Cologne joint seminar,
Universität zu Köln |
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| 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)
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Monday, April 23rd Brussels-Cologne joint seminar,
Université Libre de Bruxelles |
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| 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