Prym varieties and the canonical map of surfaces of general type

C. Ciliberto, R. Pardini, F. Tovena

Let X be a smooth complex surface of general type such that the image of the canonical map $\varphi$ of X is a surface $\Sigma$ and that $\varphi$ has degree $\delta \ge 2$. Let $\epsilon :S\to \Sigma$ be a de…