分野別セミナー

拡大版九大ポロジーセミナー
開催日：1月28日(火)
場所：W1-D-725
プログラム：
13:00〜14:00 北澤直樹氏（九州大学）
14:30〜15:30 小島道氏（九州大学）
16:00〜17:00 Boldizsar Kalmar 氏（Eotvos Lorand University/Budapest University of Technology and Economics）
講演はすべて英語です。

【講演要旨】Trisection is a certain decomposition of a 4-manifold into three 4-dimensional 1-handlebodies,
originally introduced by Gay and Kirby. They showed that any orientable, connected and closed 4-manifold admits a
trisection, and moreover, two trisections of a 4-manifold are isotopic after some stabilizations. In this talk, we will
exhibit some examples of pairs of trisections of some 4-manifolds which are shown to be non-isotopic through the
use of Nielsen equivalence. These examples were given by Islambouli in 2021 and the talk will be essentially a
survey of the result. At the end of the talk, we will give some related problems concerning trisections which are
expected to be solved by using Nielsen equivalence.