Abstract:
In the second of the series of talks we focus on the symplectic excision.
Given a closed subset $Z$ of a noncompact symplectic manifold $(M, \omega)$, we use 5 approaches for the excisability of $Z$ from $(M, \omega)$: smooth excision, symplectic excision, symplectic neighbourhood excision, Hamiltonian excision, time-independent Hamiltonian excision. The latter ones imply the former ones.
For the first example, we construct a time-independent Hamiltonian excision of a ray from any ncsp manifold.
Further examples including excising a Cantor brush and a tree.
As an application, a tree in a compact symplectic manifold can be symplectically shrunk to a point.
We will also discuss subsets of ncsp manifolds that has some types of excisions but not others.
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