Hyperelliptic plane curves of type .
Immersions of module varieties
We show that a homomorphism of algebras is a categorical epimorphism if and only if all induced morphisms of the associated module varieties are immersions. This enables us to classify all minimal singularities in the subvarieties of modules from homogeneous standard tubes.
Incollamento di punti chiusi e gruppo fondamentale algebrico e topologico
Injective endomorphisms of algebraic and analytic sets
We prove that every injective endomorphism of an affine algebraic variety over an algebraically closed field of characteristic zero is an automorphism. We also construct an analytic curve in ℂ⁶ and its holomorphic bijection which is not a biholomorphism.
Injective endomorphisms of algebraic varieties.
Intégration motivique sur les schémas formels
Nous généralisons la théorie de l’intégration motivique au cadre des schémas formels. Nous définissons et étudions l’anneau booléen des ensembles mesurables, la mesure motivique, l’intégrale motivique et nous démontrons un théorème de changement de variables pour cette intégrale.
Intrinsic Measures of Compact Complex Manifolds.
Invariant Subvarieties of Toric Varieties Which are Local Complete Intersections.
Invariants of a quadratic form attached to a tame covering of schemes
We build on preceeding work of Serre, Esnault-Kahn-Viehweg and Kahn to establish a relation between invariants, in modulo 2 étale cohomology, attached to a tamely ramified covering of schemes with odd ramification indices. The first type of invariant is constructed using a natural quadratic form obtained from the covering. In the case of an extension of Dedekind domains, mains, this form is the square root of the inverse different equipped with the trace form. In the case of a covering of Riemann...
Invariants of plane algebraic curves via representations of the braid group.
Inverting Reid's exact plurigenera formula.
Involutive birational transformations of arbitrary complexity in Euclidean spaces
A broad family of involutive birational transformations of an open dense subset of onto itself is constructed explicitly. Examples with arbitrarily high complexity are presented. Construction of birational transformations such that for a fixed integer is also presented.
Jacobian discrepancies and rational singularities
Inspired by several works on jet schemes and motivic integration, we consider an extension to singular varieties of the classical definition of discrepancy for morphisms of smooth varieties. The resulting invariant, which we call , is closely related to the jet schemes and the Nash blow-up of the variety. This notion leads to a framework in which adjunction and inversion of adjunction hold in full generality, and several consequences are drawn from these properties. The main result of the paper...
Jet schemes of complex plane branches and equisingularity
For , we determine the irreducible components of the th Jet Scheme of a complex branch and we give formulas for their number and for their codimensions, in terms of and the generators of the semigroup of . This structure of the Jet Schemes determines and is determined by the topological type of .
Joacobian surfaces in P4.
Joins of schemes, linear projections
Jung's type theorem for polynomial transformations of ℂ²
We prove that among counterexamples to the Jacobian Conjecture, if there are any, we can find one of lowest degree, the coordinates of which have the form + terms of degree < m+n.
Kodaira singularities and an extension of Arnold's strange duality
extension of adjoint line bundle sections
We prove an extension theorem of Ohsawa-Takegoshi type for line bundle sections on a subvariety of general codimension in a normal projective variety. Our method of proof gives conditions to be satisfied for such extension in a general setting, while such conditions are satisfied when the subvariety is given by an appropriate multiplier ideal sheaf.
La caractéristiqe d'Euler du complexe de Gauss-Manin.