 
Summary: CANADA RESEARCH CHAIR TIER II
SEMINAR
Faculty of Science
SPEAKER: Dr. Donald Stanley
Department of Mathematics & Statistics
University of Regina
TITLE: Lefschetz Duality Revisited
ABSTRACT:
Let P be a subpolyhedron of a closed manifold M. Lefschetz duality gives us an exact
sequence for the linear structure of the cohomology of the complement of P in M. Using
only the homotopy class of the embedding of P in M we describe how to solve the
extension problem for this exact sequence and also how to determine the algebra structure
of the cohomology in the stable case. In the unstable case the algebra structure detects
different embeddings of P in M that lie in the same homotopy class. Our methods can also
be used to study configuration spaces and the blowup of a manifold M along a
submanifold. The work on the blowup can in turn be applied to construct examples of
nonKahler symplectic manifolds.
DATE: Wednesday, January 28, 2004
TIME: 9:30  10:30 a.m.
LOCATION: Mathematics Lounge, College West 307 (CW 307)
