Projective homogeneous varieties birational to quadrics.
We study the pullback maps on cohomology groups for equivariant rational maps (i.e., monomial maps) on toric varieties. Our method is based on the intersection theory on toric varieties. We use the method to determine the dynamical degrees of monomial maps and compute the degrees of the Cremona involution.
If denotes the variety of irreducible plane curves of degree with exactly nodes as singularities, Diaz and Harris (1986) have conjectured that is a torsion group. In this note we study rational equivalence on some families of singular plane curves and we prove, in particular, that is a finite group, so that the conjecture holds for . Actually the order of is , the group being cyclic if is odd and the product of and a cyclic group of order if is even.
Gabber a déduit son théorème d’indépendance de de la cohomologie d’intersection d’un résultat général de stabilité sur les corps finis. Dans cet article, nous démontrons un analogue sur les corps locaux de ce résultat général. Plus précisément, nous introduisons une notion d’indépendance de pour les systèmes de complexes de faisceaux -adiques sur les schémas de type fini sur un corps local équivariants sous des groupes finis et nous établissons sa stabilité par les six opérations de Grothendieck...
The goal of this paper is at least two-fold. First we attempt to give a survey of some recent (and developed up to the time of the Banach Center workshop Parameter Spaces, February '94) applications of the theory of symmetric polynomials and divided differences to intersection theory. Secondly, taking this opportunity, we complement the story by either presenting some new proofs of older results (and this takes place usually in the Appendices to the present paper) or providing some new results which...