To every abelian subvariety of a principally polarized abelian variety (A,L) we canonically associate a numerical class in the Néron–Severi group of A.We prove that these classes are characterized by their intersection ...

Let f: M -> M be a fiber-preserving map where S -> M -> B is a bundle and S is a closed surface. We study the abelianized obstruction, which is a cohomology class in dimension 2, to deform f to a fixed point free map by a ...

Let f:M → M be a fiber-preserving map where S → M → B is a bundle and S is a closed surface. We study the abelianized obstruction, which is a cohomology class in dimension 2, to deform f to a fixed point free map by a ...

Generalizing the method of Faltings–Serre, we rigorously verify that certain abelian surfaces without extra endomorphisms are paramodular. To compute the required Hecke eigenvalues, we develop a method of specialization ...

Given a closed Riemann surface R of genus p >= 2 together with an anticonformal involution tau : R -> R with fixed points, we consider the group K(R, tau) consisting of the conformal and anticonformal auto-morphisms of R ...

The (-1 )-involution on the Jacobian Jr of an arbitrary Riemann surfacer of genus two leads to a singular surface, the Kummer surface Icr of Jr, which,after desingularization, defines a X-3 surface Kr . We consider ample ...

Let f: M -> M be a fiber-preserving map where S -> M -> B is a bundle and S is a closed surface. We study the abelianized obstruction, which is a cohomology class in dimension 2, to deform f to a fixed point free map by a ...

Let f: M -> M be a fiber-preserving map where S -> M -> B is a bundle and S is a closed surface. We study the abelianized obstruction, which is a cohomology class in dimension 2, to deform f to a fixed point free map by a ...