An Implementation of the Bestvina-Handel Algorithm for Surface Homeomorphisms

自由积自同态的不动子群的显式界

Explicit bounds for fixed subgroups of endomorphisms of free products

本文研究自由积自同态的不动子群，旨在给出其秩的显式界，推广了 Bestvina 和 Handel 关于自由群自同构不动子群的 Scott 猜想。

Invariant laminations for irreducible automorphisms of free groups

For every atoroidal iwip automorphism $ϕ$ of $F_N$ (i.e. the analogue of a pseudo-Anosov mapping class) it is shown that the algebraic lamination dual to the forward limit tree $T_+(ϕ)$ is obtained as "diagonal closure" of the support of the backward limit current $μ_-(ϕ)$. This diagonal closure is obtained through a finite procedure in analogy to adding diagonal leaves from the complementary components to the stable lamination of a pseudo-Anosov homeomorphism. We also give several new characterizations as well as a structure theorem for the dual lamination of $T_+(ϕ)$, in terms of Bestvina-Fe…

一种判定外自同构是否为几何的算法

An algorithm to decide if an outer automorphism is geometric

针对一般外自同构的几何性判定难题，本文提出一种构造性算法，可判定其是否由紧致曲面同胚实现并在存在时给出该同胚。