# Polarizations of Prym varieties for Weyl groups via abelianization

### Christoph Scheven

Friedrich-Alexander-Universität Erlangen, Germany### Christian Pauly

Université de Montpellier II, France

## Abstract

Let $\pi: Z \ra X$ be a Galois covering of smooth projective curves with Galois group the Weyl group of a simple and simply connected Lie group $G$. For any dominant weight $\lambda$ consider the curve $Y = Z/\Stab(\lambda)$. The Kanev correspondence defines an abelian subvariety $P_\lambda$ of the Jacobian of $Y$. We compute the type of the polarization of the restriction of the canonical principal polarization of $\Jac(Y)$ to $P_\lambda$ in some cases. In particular, in the case of the group $E_8$ we obtain families of Prym-Tyurin varieties. The main idea is the use of an abelianization map of the Donagi-Prym variety to the moduli stack of principal $G$-bundles on the curve $X$.

## Cite this article

Christoph Scheven, Christian Pauly, Polarizations of Prym varieties for Weyl groups via abelianization. J. Eur. Math. Soc. 11 (2009), no. 2, pp. 315–349

DOI 10.4171/JEMS/152