幾何学コロキウム：【講演取り消しのお知らせ】Cobordism of Morse functions, B_2 points, and their application to map germs（Dominik Wrazidlo氏，九州大学）

開催日時

2019年7月19日 16時 30分 ～ 2019年7月19日 18時 00分

場所

理学部３号館３－２０４室

講演者

Dominik Wrazidlo（九州大学IMI，日本学術振興会外国人特別研究員）

タイトル：　Cobordism of Morse functions, B_2 points, and their application to map germs

アブストラクト：
By Morse functions we mean stable real-valued smooth functions on compact manifolds possibly with boundary. In particular, the critical points of a Morse function are non-degenerate and do not lie on the boundary, and the restriction of a Morse function to the boundary is again a Morse function. One can consider several cobordism relations for Morse functions that are all based on proper stable maps of manifolds possibly with boundary into the plane. For Morse functions on surfaces, the resulting cobordism groups have been computed by O. Saeki and T. Yamamoto. Their method is based on the cohomology of the universal complex of singular fibers, and combinatorial arguments using labeled Reeb graphs.

In this talk, we compute cobordism groups of Morse functions on manifolds of arbitrary dimension. Our approach is based on manipulations of folds, cusps, and B_2 singularities. Similar methods apply to the analogous problem for Morse maps into the circle. In the end, we apply our results to generic map germs of boundary points into the plane.

講演者体調不良により講演取り消しとなりました（７月１２日記）．