Une somme amalgamée de schémas est décrite localement par un produit fibré d’anneaux. Ce texte donne un résultat global d’existence (§5.4) de schémas définis comme certaines sommes amalgamées et un procédé algébrique (§2.2) pour décrire les modules sur produits fibrés d’anneaux correspondants.
A ternary ring is an algebraic structure of type satisfying the identities and where, moreover, for any , , there exists a unique with . A congruence on is called normal if is a ternary ring again. We describe basic properties of the lattice of all normal congruences on and establish connections between ideals (introduced earlier by the third author) and congruence kernels.
Let be the algebraic closure of and be the local field of formal power series with coefficients in . The aim of this paper is the description of the set of conjugacy classes of series of order for the composition law. This work is concerned with the formal power series with coefficients in a field of characteristic which are invertible and of finite order for the composition law. In order to investigate Oort’s conjecture, I give a description of conjugacy classes of series by means...
Gröbner bases for modules are used to calculate a generalized linear immersion for a plant whose solutions to its regulation equations are polynomials or pseudo-polynomials. After calculating the generalized linear immersion, we build the controller which gives the robust regulation.
A method is presented making it possible to construct -groups with a strong theory of quasi-divisors of finite character and with some prescribed properties as subgroups of restricted Hahn groups , where are finitely atomic root systems. Some examples of these constructions are presented.