Affiliation:
University of Edinburgh
Date:
Mon, 17/10/2016 - 16:30 - 17:00
The talk will report on the current status of a joint project with Dave Benson, Caterina Campagnolo and Carmen Rovi. Werner Meyer (Bonn thesis 1972) proved that the signature $\sigma(E) \in \mathbb{Z}$ of a surface bundle $\Sigma_g \to E \to \Sigma_h$ is divisible by 4, and can be computed from a cohomology class $\tau \in H^2(\operatorname{Sp}(2g,\mathbb{Z});\mathbb{Z})$ and the monodromy $\pi_1(\Sigma_h) \to \operatorname{Sp}(2g,\mathbb{Z})$.