A note on the abelianizations of finite-index subgroups of the mapping class group
A note on the abelianizations of finite-index subgroups of the mapping class group
For some $g \geq 3$, let $\Gamma$ be a finite index subgroup of the mapping class group of a genus $g$ surface (possibly with boundary components and punctures). An old conjecture of Ivanov says that the abelianization of $\Gamma$ should be finite. In this note, we prove two theorems supporting …