Let P ∪P ′ be the two component Prym variety associated to anétale double cover˜C → C of a non-hyperelliptic curve of genus g ≥ 6 and let |2Ξ 0 | and |2Ξ ′ 0 | be the linear systems of second order theta divisors on P and P ′ respectively. The component P ′ contains canonically the Prym curve˜C. We show that the base locus of the subseries of divisors containing˜C ⊂ P ′ is exactly the curve˜C. ...

The Prym variety of a pair of coverings is defined roughly speaking as the complement of the Prym variety of one morphism in the Prym variety of another morphism. We show that this definition is symmetric and give conditions when such a Prym variety is isogenous to an ordinary Prym variety or to another such Prym variety. Moreover in order to show that these varieties actually occur we compute ...

Introduction 1 1. Kanev’s construction and Prym-Tyurin varieties of E6-type 7 2. The E6 lattice 11 3. Degenerations of Jacobians and Prym varieties 13 4. Degenerations of Prym-Tyurin-Kanev varieties 15 5. The global geometry of the Hurwitz space of E6-covers 20 6. The Prym-Tyurin map along boundary components of Hur 30 7. Ordinary Prym varieties regarded as Prym-Tyurin-Kanev varieties 39 8. The...

Let G denote a finite group and π : Z → Y a Galois covering of smooth projective curves with Galois group G. For every subgroup H of G there is a canonical action of the corresponding Hecke algebra Q[H\G/H ] on the Jacobian of the curve X = Z/H . To each rational irreducible representation W of G we associate an idempotent in the Hecke algebra, which induces a correspondence of the curve X and ...

Let π : Z → 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 λ consider the curve Y = Z/Stab(λ). The Kanev correspondence defines an abelian subvariety Pλ 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...

The Prym map of type (g, n, r) associates to every cyclic covering of degree n of a curve of genus g, ramified at a reduced divisor of degree r, the corresponding Prym variety. We show that the corresponding map of moduli spaces is generically finite in most cases. From this we deduce the dimension of the image of the Prym map.

Our main theorem is an improvement of the Criterion of Kanev about Prym–Tyurin varieties induced by correspondences, which includes correspondences with fixed points. We give some examples of Prym–Tyurin varieties using this criterion.