activity
20242026
collaborators

7 papers

math.GT2026

The Dax isomorphism for topological -manifolds

Jianfeng Lin, Yi Xie, Boyu Zhang

Let be an oriented topological -manifold with boundary. We establish a Dax isomorphism for the fundamental group of the space of embedded arcs in . Here, the embedding sp…

math.GT2026

Splitting spheres for -links in

Jianfeng Lin, Yi Xie, Boyu Zhang

We prove that every smooth two-component split sphere link admits infinitely many smooth splitting -spheres that are topologically non-isotopic. This gene…

math.SG2026

Topological symplectic manifolds and bi-Lipschitz structures

Dan Cristofaro-Gardiner, Boyu Zhang

We show that a topological symplectic manifold has a canonically associated bi-Lipschitz structure. As a corollary, we obtain the first examples of non-existence and non-uniqueness…

math.GT2026

Pseudo-isotopies of 3-manifolds with infinite fundamental groups

Jianfeng Lin, Yi Xie, Boyu Zhang

Suppose is a compact, connected, oriented 3-manifold possibly with boundary, such that is infinite. Let denote the group of s…

math.GT2025

On the mapping class groups of 4-manifolds with 1-handles

Jianfeng Lin, Yi Xie, Boyu Zhang

We develop a framework that generalizes Budney-Gabai's invariant on to 4-manifolds with 1-handles. As applications, we show that if…

math.GT2025

Dax invariants, light bulbs, and isotopies of symplectic structures

Jianfeng Lin, Weiwei Wu, Yi Xie +1

This paper addresses several isotopy problems on -manifolds. First, we classify the isotopy classes of embeddings of in that are geometrically dual to $\{\mbox…

math.DG2024

Z/2 harmonic 1-forms, R-trees, and the Morgan-Shalen compactification

Siqi He, Richard Wentworth, Boyu Zhang

This paper studies the relationship between an analytic compactification of the moduli space of flat connections on a closed, oriented 3-manifold de…