arXiv subjects
Publications and source records attributed to Guillaume Jamet.
We show that any hyperplane section of a variety which is the inverse image of a smooth variety of dimension at least 2 by an endomorphism (wich is not an automorphism) of the projective space, is linearly complete. We stress the case of smooth surfaces in projective fourspace.
In this paper we give smoothness criterions for a good quotient Y of a smooth variety X by a reductive group G. Our results partially answer a question raised by J. Fogarty in the case where G is a finite group. They also give a converse to a theorem of M. Brion, telling that invariant horizontal differential forms on X and differential forms on Y are isomorphic under the assumption that Y is smooth. The proof of our criterion rely on a new description of the dualizing sheaf of Y established in this article.