On the mapping class groups of 4-manifolds with 1-handles
Jianfeng Lin, Yi Xie, Boyu Zhang
TL;DR
The paper addresses the problem of central elements in mapping class groups of 4-manifolds with a 1-handle by extending Budney-Gabai's W3 framework. It constructs a scanning map from diffeomorphism groups to embedding spaces and builds a cosimplicial/configuration-space framework to study embeddings via a spectral-sequence approach. The main results show that the image of the 1-handle diffeomorphism group into the ambient mapping class group has infinite rank under natural hypotheses, with extensions to homeomorphisms. This work links embedding calculus, configuration-space invariants, and spectral-sequence methods to provide a broad method for detecting infinite-rank centers in mapping class groups of 4-manifolds.
Abstract
We develop a framework that generalizes Budney-Gabai's $W_3$ invariant on $π_0\textrm{Diff}(S^1\times D^3,\partial)$ to 4-manifolds with 1-handles. As applications, we show that if $M=(S^1\times D^3)\natural \hat M$ where $\hat M$ either has the form $I\times Y$ or is a punctured aspherical manifold, then the center of the mapping class group of $M$ is of infinite rank.
