On the Griffiths group of the cubic sevenfold.
We show that the Néron–Severi group of the Prym variety for a degree three unramified Galois covering of a hyperelliptic Riemann surface has a distinguished subgroup of rank three. For the general hyperelliptic curve, the algebra of Hodge cycles on the Prym variety is generated by this group of rank three.
We describe the polarised Hodge structure on the symmetric powers of a smooth projective curve.
We study the structure of the filtered Gauss-Manin system associated to a holomorphic function with an isolated singularity, and get a basis of the Brieskorn lattice over such that the action of is expressed byfor two matrices with semi-simple, where is the basis. As an application, we calculate the -function of in the case of two variables.
Let be a normal crossing divisor in the smooth complex projective algebraic variety and let be a tubular neighbourhood of in . Using geometrical properties of different intersections of the irreducible components of , and of the embedding , we provide the “normal forms” of a set of geometrical cycles which generate , where is one of the following pairs , , , and . The construction is compatible with the weights in of Deligne’s mixed Hodge structure. The main technical part...