On a lifting problem for principal Dedekind domains
Let F ∈ ℂ[x,y]. Some theorems on the dependence of branches at infinity of the pencil of polynomials f(x,y) - λ, λ ∈ ℂ, on the parameter λ are given.
Some results and problems that arise in connection with the foundations of the theory of ruled and rational field extensions are discussed.
In this paper, we show that if and are algebraic real hypersurfaces in (possibly different) complex spaces of dimension at least two and if is a holomorphic mapping defined near a neighborhood of so that , then is also algebraic. Our proof is based on a careful analysis on the invariant varieties and reduces to the consideration of many cases. After a slight modification, the argument is also used to prove a reflection principle, which allows our main result to be stated for mappings...
On généralise ici un théorème de Grauert-Manin pour les courbes (problème de Mordell pour les corps de fonctions). Soit un corps de fonctions algébriques sur un corps algébriquement clos de caractéristique 0, une variété propre et lisse sur , dont le fibré cotangent est ample; si l’ensemble de ses points rationnels est Zariski-dense, la variété se redescend sur .