Nariya Kawazumi

(University of Tokyo)

(University of Tokyo)

Seminar

Tuesday, 28 September, 2010, at 16:15-17:15, in Aud. D3 (1531-215)

Abstract:

Let \Sigma_{g,1} be a compact connected oriented surface of genus g (\geq 1) with one boundary component, \pi the fundamental group of the surface \Sigma_{g,1}. We prove any symplectic expansion of the group \pi in the sense of Massuyeau induces a natural homomorphism of the Goldman Lie algebra of the surface \Sigma_{g,1} to an extension of Kontsevich's ''associative'' Lie algebra. As applications, we obtain an explicit escription of the action of Dehn twists on the completed group ring of the group \pi, and compute the center of the Goldman Lie algebra of the surface \Sigma_{\infty,1} = \varinjlim_{g\to\infty}\Sigma_{g,1}.

This talk is based on a joint work with Yusuke Kuno (Hiroshima University, JSPS)

Contact person: Jørgen Ellegaard Andersen