7 papers
Big mapping class groups and the co-Hopfian property
Javier Aramayona, Christopher J. Leininger, Alan McLeay
We study injective homomorphisms between big mapping class groups of infinite-type surfaces. First, we construct (uncountably many) examples of surfaces without boundary whose (pur…
Ideally, all infinite type surfaces can be triangulated
Alan McLeay, Hugo Parlier
We show that any surface of infinite type admits an ideal triangulation. Furthermore, we show that a set of disjoint arcs can be completed into a triangulation if and only if, as a…
Homeomorphic subsurfaces and the omnipresent arcs
Federica Fanoni, Tyrone Ghaswala, Alan McLeay
In this article, we are concerned with various aspects of arcs on surfaces. In the first part, we deal with topological aspects of arcs and their complements. We use this understan…
The mapping class group of the Cantor tree has only geometric normal subgroups
Alan McLeay
A normal subgroup of the (extended) mapping class group of a surface is said to be geometric if its automorphism group is the mapping class group. We prove that in the case of the…
Big Torelli groups: generation and commensuration
Javier Aramayona, Tyrone Ghaswala, Autumn E. Kent +3
For any surface of infinite topological type, we study the Torelli subgroup of the mapping class group , whose elements are those mapping classe…
Geometric normal subgroups in mapping class groups of punctured surfaces
Alan McLeay
We prove that many normal subgroups of the extended mapping class group of a surface with punctures are geometric, that is, that their automorphism groups and abstract commensurato…