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Universität Augsburg
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Universität Augsburg
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Dr. Renée Hoekzema
University of Oxford
spricht am
Montag, 15. Januar 2018
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16:00 Uhr
im
Raum 2004 (L1)
über das Thema:
| Abstract: |
| Orientable manifolds have even Euler characteristic unless the dimension is a multiple of 4. I give a generalisation of this theorem: k-orientable manifolds have even Euler characteristic (and in fact vanishing top Wu class), unless their dimension is 2k+1m for some integer m. Here we call a manifold k-orientable if the ith Stiefel-Whitney class vanishes for all 0< i< 2k. This theorem is strict for k=0,1,2,3, but whether there exist 4-orientable manifolds with an odd Euler characteristic is a new open question. Such manifolds would have dimensions that are a multiple of 32. I discuss manifolds of dimension high powers of 2 and present the results of calculations on the cohomology of the second Rosenfeld plane, a special 64-dimensional manifold with odd Euler characteristic. |
| Hierzu ergeht herzliche Einladung. |
| Prof. Dr. Fabian Hebestreit |
Kaffee, Tee und Gebäck eine halbe Stunde vor Vortragsbeginn im Raum 2006 (L1).