A lower bound of the distortion of the Torelli group in the mapping   class group with boundary components
  We prove that each Torelli group of an orientable surface with any number of boundary components is at least exponentially distorted in the mapping class group by using Broaddus-Farb-Putman's techniques. Further we show that the distortion of each Torelli group in the level $d$ mapping class group is the same as that of in the mapping class group. 
Erika Kuno, Genki Omori
math.GT math.GR