Resumen de Nikulin involutions on K 3 surfaces

Bert Van Geemen, Alessandra Sarti

• We study the maps induced on cohomology by a Nikulin (i.e. a symplectic) involution on a K3 surface. We parametrize the 11-dimensional irreducible components of the moduli space of algebraic K3 surfaces with a Nikulin involution and we give examples of the general K3 surface in various components. We conclude with some remarks on Morrison¿Nikulin involutions, these are Nikulin involutions which interchange two copies of E 8(-1) in the Néron Severi group