Lei Chen

activity

20172022

most citedThe universal surface bundle over the Torelli space has no sections

1 citations · 2 across the 7 of their papers we have counts for

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14 papers · 1 filter

math.GT2022

Nielsen Realization for sphere twists on 3-manifolds

Lei Chen, Bena Tshishiku

For a 3-manifold M, the twist group Twist(M) is the subgroup of the mapping class group Mod(M) generated by twists about embedded 2-spheres. We study the Nielsen realization proble…

math.GT2020

From pure braid groups to hyperbolic groups

Lei Chen

In this note we show that any homomorphism from a pure surface braid group to a torsion-free hyperbolic group either has a cyclic image or factors through a forgetful map. This ext…

math.GT2020

There are no exotic actions of diffeomorphism groups on 1-manifolds

Lei Chen, Kathryn Mann

Let $M$ be a manifold, $N$ a 1-dimensional manifold. Assuming $r \neq = dim (M) + 1$ , we show that any nontrivial homomorphism $ρ : Diff_{c}^{r} (M) \to Homeo (N)$ has a standard…

math.GT2020

Global fixed points of mapping class group actions and a theorem of Markovic

Lei Chen, Nick Salter

We give a short and elementary proof of the non-realizability of the mapping class group via homeomorphisms. This was originally established by Markovic, resolving a conjecture of…

math.GT2020★ 1 cited

Non-realizability of the pure braid group as area-preserving homeomorphisms

Lei Chen

Let $Homeo_{+} (D_{n}^{2})$ be the group of orientation-preserving homeomorphisms of $D^{2}$ fixing the boundary pointwise and $n$ marked points as a set. Nielsen realization problem…

math.GT2020

Vanishing of the Euler class in Power subgroups of the punctured mapping class group

Lei Chen

In this paper, we use a result of Dahmani to show that the Euler class of some power subgroup (the subgroup normally generated by a fixed power of Dehn twist about a non-separating…