Décomposition cellulaire de variétés paramétrant des idéaux homogènes de . Incidence des cellules I
Décomposition de la cohomologie cyclique bivariante des algèbres commutatives.
Décomposition du Galois-module des entiers d'une extension cyclique de degré premier d'un corps local ou d'un corps de nombres
Décomposition du Galois-module des entiers d'une extension cyclique de degré premier d'un corps de nombres ou d'un corps local
Soit un anneau de Dedekind, de corps des fractions , et soit une extension galoisienne de , dont le groupe de Galois est cyclique d’ordre premier. On note la clôture intégrale de dans . Il existe une unique décomposition du -module en somme directe de sous-modules indécomposables. On détermine cette décomposition lorsque est un corps local ou un corps de nombres. Le résultat dépend d’une part des caractères irréductibles de sur , d’autre part des nombres de ramification associés...
Decomposition of finitely generated modules using Fitting ideals
Let be a commutative Noetherian ring and be a finitely generated -module. The main result of this paper is to characterize modules whose first nonzero Fitting ideal is a product of maximal ideals of , in some cases.
Decomposition of the diagonal action of on the coinvariant space of .
Décompositions primaires dans les catégories de Grothendieck commutatives. II.
Décompositions primaires dans les catégories de Grothendieck commutatives. I.
Deformation of determinantal schemes
Deformation Theory (Lecture Notes)
First three sections of this overview paper cover classical topics of deformation theory of associative algebras and necessary background material. We then analyze algebraic structures of the Hochschild cohomology and describe the relation between deformations and solutions of the corresponding Maurer-Cartan equation. In Section we generalize the Maurer-Cartan equation to strongly homotopy Lie algebras and prove the homotopy invariance of the moduli space of solutions of this equation. In the last...
Deformation to the normal cone, rationality and the Stückrad-Vogel cycle.
Deformation von Cohen-Macaulay Algebren.
Deformation von Gorenstein-Singularitäten der Kodimension 3.
Deformations of border bases
Deformations of free and linear free divisors
We study deformations of free and linear free divisors. We introduce a complex similar to the de Rham complex whose cohomology calculates the deformation spaces. This cohomology turns out to be zero for all reductive linear free divisors and to be constructible for Koszul free divisors and weighted homogeneous free divisors.
Deformations of graded algebras.
Deformations of maximal Cohen-Macaulay modules.
Deforming syzygies of liftable modules and generalised Knörrer functors
Maps between deformation functors of modules are given which generalise the maps induced by the Knörrer functors. These maps become isomorphisms after introducing certain equations in the target functor restricting the Zariski tangent space. Explicit examples are given on how the isomorphisms extend results about deformation theory and classification of MCM modules to higher dimensions.
Degeneration of the Kummer sequence in characteristic
We study a deformation of the Kummer sequence to the radicial sequence over an -algebra, which is somewhat dual for the deformation of the Artin-Schreier sequence to the radicial sequence, studied by Saidi. We also discuss some relations between our sequences and the embedding of a finite flat commutative group scheme into a connected smooth affine commutative group schemes, constructed by Grothendieck.
Degree estimate for subalgebras generated by two elements
We develop a new combinatorial method to deal with a degree estimate for subalgebras generated by two elements in different environments. We obtain a lower bound for the degree of the elements in two-generated subalgebras of a free associative algebra over a field of zero characteristic. We also reproduce a somewhat refined degree estimate of Shestakov and Umirbaev for the polynomial algebra, which plays an essential role in the recent celebrated solution of the Nagata conjecture and the strong...