Geometry
Seminar
Divided
difference operators in equivariant cohomology
Professor Reyer Sjamaar
Cornell University
Abstract
Divided difference
operators were invented by Newton
for the purpose of numerical interpolation. More recently, they showed up
in work of Demazure and Bernstein-Gelfand-Gelfand on the invariant theory of
compact Lie groups and the cohomology of flag varieties. In this talk,
which describe joint work with Megumi Harada, Tara Holm and Greg Landweber, I
will show that they act naturally as bivariant operations in certain
equivariant cohomology theories. This leads to various computational
results as well as to a more precise version of Atiyah's "splitting
principle" for equivariant K-theory.
Date:
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February 20, 2008 (Wednesday)
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Time:
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2:00 – 3:00pm
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Place:
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Room 517, Meng Wah Complex, HKU
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Tea will be held in Room
516, Meng Wah Complex before the
lecture, at 1:45pm