Title    name
Geometric Topology Fair 2017
  Speaker Takuya Sakasai
  Date 2017-05-11
  Place KAIST
  File  의 1 번째 Real Media 동영상입니다.   
Abstract : We construct an abelian quotient of the symplectic derivation Lie algebra of the free Lie algebra generated by the fundamental representation of the symplectic group. It gives an alternative proof of the fact first shown by Bartholdi that the top rational homology group of the moduli space of metric graphs of rank 7 is one dimensional. As an application, we construct a non-trivial abelian quotient of the homology cobordism group of a surface of positive genus. This talk is based on joint works with Shigeyuki Morita, Masaaki Suzuki and Gwénaël Massuyeau.