具有非零示性类的非球面流形
Aspherical manifolds with nonvanishing tautological classes
浏览论文内容
中文总结 AI 辅助
本文构造了一类具有非平凡中心基本群的非球面流形,其无穷多个示性类非零且非幂零,并给出不紧致流形边界的例子,从而反驳了 Hebestreit--Land--Lück--Randal-Williams 猜想。
中文摘要 AI 辅助
对于每个偶数整数 $m\geq 2$,我们构造一个闭的、可定向的、光滑的、非球面的 $(2m+1)$ 维流形,其基本群具有非平凡的中心,并且在其同伦平凡微分同胚群的分类空间的 $\mathbb{F}_2$ 上同调中,无穷多个示性类非零且非幂零。将计算特化到上同调度 $0$ 时,给出了此类流形不紧致光滑流形边界的例子。这些为 Hebestreit--Land--Lück--Randal-Williams 的一个猜想提供了反例。
英文摘要
For every even integer $m\geq 2$, we construct a closed, orientable, smooth, aspherical $(2m+1)$-manifold whose fundamental group has nontrivial center and for which infinitely many tautological classes in the $\mathbb{F}_2$-cohomology of the classifying space of its group of homotopically trivial diffeomorphisms are nonzero and not nilpotent. Specializing the calculation to cohomological degree $0$ gives examples of such manifolds that do not bound compact smooth manifolds. These provide counterexamples to a conjecture of Hebestreit--Land--Lück--Randal-Williams.