The large scale geometry of big mapping class groups

Israel Morales Jiménez
UNAM-Oaxaca (México)
Abstract:
The mapping class group, 
\[Map(S)\]
, of an orientable surface 
\[S\]
, is the group of all isotopy classes of homeomorphisms of 
\[S\]
to itself. For surfaces of finite type (surfaces whose fundamental group is finitely generated), 
\[Map(S)\]
is a discrete topological group, it is finitely generated and its large-scale geometry has been extensively studied.
The topology of 
\[Map(S)\]
is more interesting if 
\[S\]
is an orientable infinite-type surface; it is uncountable, topologically perfect, totally disconnected, and it has the structure of a Polish group. This class of groups is called “big mapping class groups (big 
\[MCGs\]
)”.
Recently, based on the Rosendal framework, K. Mann and K. Rafi have started the study of the large-scale geometry of big 
\[MCGs\]
. In this talk I will present generalities of the theory to study the large-scale geometry of topological groups and of big 
\[MCGs\]
. At the end, I will present some results obtained in a joint work with Rita Jimenez Rolland where we characterize the large-scale geometry of 
\[Map(S)\]
when 
\[S\]
is a surface of infinite type with space of ends homeomorphic to 
\[\omega^{\alpha}+1\]
.