Raggi estremali di varietà proiettive lisce
Ramification dans le corps des modules
Soit un revêtement de la droite projective défini sur , de groupe de monodromie . Soit le compositum des corps de rationalité des points de branchement , et le corps des modules correspondants. Partant du lien entre corps des modules et espaces de Hurwitz, on étudie la géométrie et l’arithmétique de ces espaces et des espaces de configuration de points complétés pour évaluer la ramification dans des mauvaises places de qui ne divisent pas l’ordre de , mais où les points de branchements...
Ramification divisors for branched coverings of IPn.
Ramification in etale cohomologie.
Rational 1- and 2-cuspidal plane curves.
Rational functions without poles in a compact set
Let X be an irreducible nonsingular complex algebraic set and let K be a compact subset of X. We study algebraic properties of the ring of rational functions on X without poles in K. We give simple necessary conditions for this ring to be a regular ring or a unique factorization domain.
Rational intersection cohomology of quotient varieties.
Rational Isogenies of Prime Degree.
Rational Puiseux expansions
Rational real algebraic models of topological surfaces.
Rationalité des Singularités Canoniques.
Rationality of the quotient of ℙ2 by finite group of automorphisms over arbitrary field of characteristic zero
Let be a field of characteristic zero and G be a finite group of automorphisms of projective plane over . Castelnuovo’s criterion implies that the quotient of projective plane by G is rational if the field is algebraically closed. In this paper we prove that is rational for an arbitrary field of characteristic zero.
Real algebraic threefolds I. Terminal singularities.
The aim of this series of papers is to develop the theory of minimal models for real algebraic threefolds. The ultimate aim is to understand the topology of the set of real points of real algebraic threefolds. We pay special attention to 3–folds which are birational to projective space and, more generally, to 3–folds of Kodaira dimension minus infinity.present work contains the beginning steps of this program. First we classify 3–dimensional terminal singularities over any field of characteristic...
Real equivalence of complex matrix pencils and complex projections of real Segre varieties.
Recent Advances in the theory of minimal models.
Reconstructing birational maps from their face functions.
Reduction and lifting of special metacyclic covers
Reduction and specialization of polynomials
We show explicit forms of the Bertini-Noether reduction theorem and of the Hilbert irreducibility theorem. Our approach recasts in a polynomial context the geometric Grothendieck good reduction criterion and the congruence approach to HIT for covers of the line. A notion of “bad primes” of a polynomial P ∈ ℚ[T,Y] irreducible over ℚ̅ is introduced, which plays a central and unifying role. For such a polynomial P, we deduce a new bound for the least integer t₀ ≥ 0 such that P(t₀,Y) is irreducible...
Réduction d'albanèse d'un morphisme propre et faiblement kahlérien. II. Groupes d'automorphismes relatifs
Réduction d'albanèse d'un morphisme propre et faiblement kahlérien. I