幾何解析セミナー

過去の記録 ~07/26次回の予定今後の予定 07/27~

担当者 今野北斗,高津飛鳥,本多正平
セミナーURL https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/

2025年07月10日(木)

14:00-15:00   数理科学研究科棟(駒場) 056号室
Jeff Viaclovsky 氏 (University of California, Irvine)
Fibrations on the $6$-sphere and Clemens threefolds (英語)
[ 講演概要 ]
Let $Z$ be a compact, connected $3$-dimensional complex manifold with vanishing first and second Betti numbers and non-vanishing Euler characteristic. We prove that there is no holomorphic mapping from $Z$ onto any $2$-dimensional complex space. In other words, $Z$ can only possibly fiber over a curve. This result applies in particular to a class of threefolds, known as Clemens threefolds, which are diffeomorphic to a connected sum of $k$ copies of $S^3 \times S^3$ for $k > 1$. This result also gives a new restriction on any hypothetical complex structure on the $6$-sphere $S^6$. This is joint work with Nobuhiro Honda.