Invarianten der degenerierten Fasern in lokalen Familien von Kurven.
Invarianten quasihomogener vollständiger Durchschnitte.
Invarianten unipotenter Gruppen.
Invariants de classes : propriétés fonctorielles et applications à l’étude du noyau
L’homomorphisme de classes mesure la structure galoisienne de torseurs – sous un schéma en groupes fini et plat – obtenus grâce au cobord d’une suite exacte. Son introduction est due à Martin Taylor (la suite exacte étant une isogénie entre schémas abéliens). Nous commençons par énoncer quelques propriétés générales de cet homomorphisme, puis nous poursuivons son étude dans le cas où la suite exacte est donnée par la multiplication par sur une extension d’un schéma abélien par un tore.
Invariants de plusieurs formes binaires
Invariants des courbes de Frey-Hellegouarch et grands groupes de Tate-Shafarevich
Invariants d'un sous-groupe unipotent maximal d'un groupe semi-simple
Soit un groupe algébrique semi-simple complexe, un sous-groupe unipotent maximal de , un tore maximal de normalisant . Si est un -module rationnel de dimension finie, alors opère sur l’algèbre des fonctions polynomiales sur ; la structure de -module de est décrite par la -algèbre des -invariants de . Cette algèbre est de type fini et multigraduée (par le degré de et le poids par rapport à ). On donne une formule intégrale pour la série de Poincaré de cette algèbre graduée....
Invariants numériques des groupes de Hilbert.
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 bi-Lipschitz equivalence of real analytic functions
We construct an invariant of the bi-Lipschitz equivalence of analytic function germs (ℝⁿ,0) → (ℝ,0) that varies continuously in many analytic families. This shows that the bi-Lipschitz equivalence of analytic function germs admits continuous moduli. For a germ f the invariant is given in terms of the leading coefficients of the asymptotic expansions of f along the sets where the size of |x| |grad f(x)| is comparable to the size of |f(x)|.
Invariants of four subspaces
We consider problems in invariant theory related to the classification of four vector subspaces of an -dimensional complex vector space. We use castling techniques to quickly recover results of Howe and Huang on invariants. We further obtain information about principal isotropy groups, equidimensionality and the modules of covariants.
Invariants of plane algebraic curves via representations of the braid group.
Invariants of real symplectic four-manifolds out of reducible and cuspidal curves
We construct invariants under deformation of real symplectic four-manifolds. These invariants are obtained by counting three different kinds of real rational -holomorphic curves which realize a given homology class and pass through a given real configuration of (the appropriate number of) points. These curves are cuspidal curves, reducible curves and curves with a prescribed tangent line at some real point of the configuration. They are counted with respect to some sign defined by the parity of...
Invariants of several matrices.
Invariants of singularities of polynomials in two complex variables and the Newton diagrams.
Invariants of Unipotent Radicals.
Invariants polaires de courbes planes.
Invariants symétriques entiers des groupes de Weyl et torsion.
Invariants symétriques et fibrés vectoriels sur les courbes.
Invariants, torsion indices and oriented cohomology of complete flags
Let be a split semisimple linear algebraic group over a field and let be a split maximal torus of . Let be an oriented cohomology (algebraic cobordism, connective -theory, Chow groups, Grothendieck’s , etc.) with formal group law . We construct a ring from and the characters of , that we call a formal group ring, and we define a characteristic ring morphism from this formal group ring to where is the variety of Borel subgroups of . Our main result says that when the torsion index...