BerlinHamburgSeminar am 26.6.2017
Vsevolod Shevchishin (Olsztyn) On symplectic mapping class group of rational 4manifolds: Presentation in the cases D_{l} and E_{5}
The symplectic mapping class group Symp(X,ω)
is the group of symplectomorphisms of (X,ω)
modulo symplectic isotopies. It appears that Symp(X,ω)
depends not only on the manifold X, but also on the symplectic
form.
In my talk I describe two special types of symplectic forms
on rational 4manifold (lfold blowups of CP^{2}),
called D_{l} and E_{l}. For symplectic forms of those
types I describe a construction which allows to find a natural geometric
presentation of the group Symp(X,ω), and
make a calculation for the types D_{l} and E_{5}.
Kyler Siegel (MIT) Subflexible symplectic manifolds and deformed symplectic invariants
One school of symplectic geometers believes that every symplectic creature either (a) satisfies an h principle or (b) has some nontrivial pseudoholomorphic curve invariant. Recent years have considerably progressed our understanding of the objects constituting category (a). In this talk, I will construct a class of examples, called "subflexible", which lie surprisingly close to the interface between (a) and (b). I will explain what types of symplectic invariants one must use to properly understand these examples and place them in category (b). Time permitting, I will end with some speculations about future symplectic invariants and exotica.
