**Date & Time:**Friday, July 26, 2013, 15:30-16:30

**Venue:** Ramanujan Hall

**Title:**Projective Modules and Various Avatars of the Euler Characteristic

**Speaker:**Sarang Sane, University of Kansas

**Abstract:** We trace a very brief history of the Euler class, beginning with the Euler characteristic in
graph theory/combinatorics through its relation with the obstruction class in topology, finally get to
the more recent notion of the Euler class in algebra/geometry and its use as an obstruction to the
splitting of projective modules. This recent notion has two approaches, Euler class groups and Chow-
Witt groups. We will briefly discuss the first approach and hope to delve deeper into the second
approach.
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