Seminar

Symplectic groups and cobordism categories

Higher algebraic structures in algebra, topology and geometry

01 March 14:15 - 16:00

Fabian Hebestreit - University of Bonn

The goal of the talk will be to explain joint work with M.Land and T.Nikolaus, in which we compute the so-called stable part of the cohomology of symplectic and orthogonal groups over the integers to a large extent, in particular at the previously mysterious prime 2. Our approach is via the group completion theorem, which relates the stable cohomology of these arithmetic groups (over general rings) to that of certain Grothendieck-Witt spaces. Recent work with W.Steimle identifies these in terms of algebraic cobordism categories, whence they can be analysed using the tools set-up in our previous joint work with B.Calmès, E.Dotto, Y.Harpaz, K.Moi and D.Nardin.

 

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Organizers
Gregory Arone
Stockholm University
Tilman Bauer
KTH Royal Institute of Technology
Alexander Berglund
Stockholm University
Søren Galatius
University of Copenhagen
Jesper Grodal,
University of Copenhagen
Thomas Kragh
Uppsala University

Program
Contact

Alexander Berglund

alexb@math.su.se

Søren Galatius

galatius@math.ku.dk

Thomas Kragh

thomas.kragh@math.uu.se

Other
information

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